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4NEC2?
Jim GM4DHJ ... wrote:
"Stephen Thomas Cole" wrote in message ... Roger Hayter wrote: Stephen Thomas Cole wrote: Roger Hayter wrote: mm0fmf wrote: snip Of course none of us would **** on Burt if he were on fire. Apart from Dicky 'Rimjob' Brown. But that's because he's trying to hide the fact he lied about his licence level. You say "none of us" - there are only three of you! Most group users don't particularly love Reay and his acolytes much more than Spike, I would think. I'd **** on Burt if he weren't on fire. Does that make you feel better, Rog? I'd also put a dog dirt through his letterbox. Quite so. But there are still only three of you. If I were you, Rog, I wouldn't take a straw poll on how many of the group's regulars would put a dog dirt through your letterbox. I wouldn't do that to anybody...... Thanks for the re****, Jim. -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
On 15 Oct 2018 19:36:42 GMT
Stephen Thomas Cole wrote: Geoff wrote: On Mon, 15 Oct 2018 16:46:06 +0000 Spike wrote: On 14/10/2018 11:57, Geoff wrote: On Sun, 14 Oct 2018 11:55:13 +0000 Spike wrote: On 14/10/2018 11:44, Geoff wrote: On Sun, 14 Oct 2018 11:39:58 +0000 Spike wrote: On 14/10/2018 11:04, Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. Then we only have your word that it ever exsisted. I choose not to believe a word of it. 'It's been deleted' means it did exsist. You can't delete was was never posted. You might ask yourself why it was deleted. That's all you need to know about his ego and and his ability with radio. We only have your word for any of that. I choose not to believe a word of it. JFTR the offending message was posted in the group free.uk.amateur-radio, on the 1st of December 2013. Some news servers will carry messages this far back, the one used for this exercise has messages back to 27 June 2003. Downloading all available messages from that group shows that the offending message has 'disappeared'. We only have your word for that. I choose not to believe you. A response to the offending message remains and quotes in full the original message. The OP's answer to that response has also 'disappeared'. The full text of the offending message was reposted by the responder. It's been reposted here too: "Was pottering at my radio last night, heard the scream of data being sent and was triggered to revisit a long parked project; getting going on RTTY! Here's the hardware I'm using: Yaesu FT757-GXii Serial/USB cable interface thing PowerMac G4 running CocoaModem I've got everything hooked up, have CocoaModem configured and displaying a waterfall but when set to RTTY mode it's just decoding gibberish... Other than a couple of short spells at club days, this is my first go at this and I have no idea what I'm doing... Any tips? It confirms the confusion in the OP's mind concerning which sideband to use on 40m, just as was stated. No, it doesn't. Even his followup: "Will do. I was doing this on 40m, so had the rig on LSB. Would people use USB for RTTY? Just Googled and I see LSB is customary for RTTY, which I was vaguely aware of... I need to do more reading!" Confirms that he knew which sideband to use on 40. It's RTTY that he has the doubt about. . It is left to others to speculate on why two such embarrassing messages should have 'disappeared' out of the 530+ from the OP that remain. The original message can be found on Google Groups: https://groups.google.com/forum/#!or...A/_ityI76x0IMJ Feel free to choose to believe what you will. I believe that you are a bitter, spiteful old man who will say whatever suits his ends. I think Burt’s gotten to. Steve, Burt's up to his neck in ****ed-up-juice, Steve. Steve, all he can do is spit, Steve. Steve, Thanks, Steve. |
4NEC2?
On Mon, 15 Oct 2018, Jim GM4DHJ ... wrote:
"Gareth's Downstairs Computer" wrote in message ... On 14/10/2018 23:14, Ralph Mowery wrote: I think the tests have gotten away from the technical part of ham radio and are now geared more to the operating practices. It is never too late to correct such an egregious mistake, for operating as such is CB Radio whereas Amateur / Ham Radio is a whole-life technical pursuit. I have been persuing an HRO500 since the 60's .......... I once saw a Galaxy R-530, a somewhat similar general coverage receiver, but from later in the sixties. All I'd ever seen was the ads, it was actually bigger than I expected. I have no idea how that landed in a local's hands, but I sort of knew the guy who bought it, and he seemed ahppy. This was about 20 years ago. Michael |
4NEC2?
On Mon, 15 Oct 2018, Ralph Mowery wrote:
In article , says... Consider a 2 tone signal at the 9MHz USB IF, comprising 900Hz and 1300Hz tones. The components will be 9.0009 and 9.0013 Subtract the VFO at 5.5MHz: 9.0009 - 5.5 = 3.50009 9.0013 - 5.5 = 3.50013 Nothing has been inverted. The 80m signal is still upper sideband. GB3BERNIE Ralph is posting from rec.radio.amateur.antenna and google groups strips the crosspost - without a repeater, he's not going to answer you. Try it the other way around and use a ssb generated at 5 mhz and the vfo at 9 mhz. It is difficult for me to remember which was used for the vfo and ssb generator. I think the origins are with a 5MHz IF. This has come up before, the same explanation given, yet if I wasn't sick and did the figuring, I think it's that the 9Mhz one wasn't it, but a 5MHz IF does do the inversion. But I can't remember what rig had a 5MHz IF. THey existed, but the ones I can think of came later. So maybe it was a phasing rig, but which did conversion rather than generate the SSB signal on the signal frequency. The Central Electronics 10 transmitter maybe, reinforced by their later 20, but I havent' checked. There was a popular rig in QST that worked out the figures so the low IF was converted up to an intermediate frequency with one crystal, one caused no inversion, but if you multiplied the crystal frequency by three, it was high side and inverted the sideband. But since it did both sidebands, it wouldn't have been a standard for LSB below a certain frequency, There were early ssb rigs that didn't have selectable sideband, they just picked conversion frequency properly so below 10MHz, it was LSB, and above was USB. Since nobody used the opposite sideband, no need for a switch. Michael |
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Stephen Thomas Troll wrote:
On 15 Oct 2018 19:36:42 GMT Stephen Thomas Cole wrote: Geoff wrote: On Mon, 15 Oct 2018 16:46:06 +0000 Spike wrote: On 14/10/2018 11:57, Geoff wrote: On Sun, 14 Oct 2018 11:55:13 +0000 Spike wrote: On 14/10/2018 11:44, Geoff wrote: On Sun, 14 Oct 2018 11:39:58 +0000 Spike wrote: On 14/10/2018 11:04, Geoff wrote: On Sun, 14 Oct 2018 08:50:13 +0000 Spike wrote: On 14/10/2018 01:32, Jeff Liebermann wrote: wrote: Gareth once complained about a mobile CB set-up he installed in a 4x4 couldn’t reach further than a quarter mile. That’s all you need to know about Gareth and radio. He probably didn't need any antenna at 1/4 mile (400 meters). snip interesting detection story Stephen Thomas Cole, the PP, just after gaining his UK Full licence by 'acing' all three exams, appeared on a UK Amateur group asking which sideband he should use on 40m. That's all you need to know about him and and his ability with radio. That sounds interesting - can you provide a link to that post? No. For some reason it's been deleted. Then we only have your word that it ever exsisted. I choose not to believe a word of it. 'It's been deleted' means it did exsist. You can't delete was was never posted. You might ask yourself why it was deleted. That's all you need to know about his ego and and his ability with radio. We only have your word for any of that. I choose not to believe a word of it. JFTR the offending message was posted in the group free.uk.amateur-radio, on the 1st of December 2013. Some news servers will carry messages this far back, the one used for this exercise has messages back to 27 June 2003. Downloading all available messages from that group shows that the offending message has 'disappeared'. We only have your word for that. I choose not to believe you. A response to the offending message remains and quotes in full the original message. The OP's answer to that response has also 'disappeared'. The full text of the offending message was reposted by the responder. It's been reposted here too: "Was pottering at my radio last night, heard the scream of data being sent and was triggered to revisit a long parked project; getting going on RTTY! Here's the hardware I'm using: Yaesu FT757-GXii Serial/USB cable interface thing PowerMac G4 running CocoaModem I've got everything hooked up, have CocoaModem configured and displaying a waterfall but when set to RTTY mode it's just decoding gibberish... Other than a couple of short spells at club days, this is my first go at this and I have no idea what I'm doing... Any tips? It confirms the confusion in the OP's mind concerning which sideband to use on 40m, just as was stated. No, it doesn't. Even his followup: "Will do. I was doing this on 40m, so had the rig on LSB. Would people use USB for RTTY? Just Googled and I see LSB is customary for RTTY, which I was vaguely aware of... I need to do more reading!" Confirms that he knew which sideband to use on 40. It's RTTY that he has the doubt about. . It is left to others to speculate on why two such embarrassing messages should have 'disappeared' out of the 530+ from the OP that remain. The original message can be found on Google Groups: https://groups.google.com/forum/#!or...A/_ityI76x0IMJ Feel free to choose to believe what you will. I believe that you are a bitter, spiteful old man who will say whatever suits his ends. I think Burt’s gotten to. Steve, Burt's up to his neck in ****ed-up-juice, Steve. Steve, all he can do is spit, Steve. Steve, Thanks, Steve. I suppose, when you think about it, Burt’s the usual suspect that my presence here has caused most trouble for. I mean, it was in the middle of his obsessed grandstanding against me I unn.config that he dropped that Burton Bradstock bollock and my continual referencing of that starting from a couple of months later has permanently involuntarily renamed him. Additionally, it’s also down to me that whenever a ukra regular hears the term “car aerial” they see in their mind’s eye Burt crying in his living room as two small children throw stones at his windows. Poor Old Burt, the scrotum-necked feeble ****. Years of show ponying and smuggery he’d invested in building up his ukra profile, and it’s all gone down the drain. He’s very bitter about it. The only other poster I’ve possibly derailed near as much as Burt is Rich, which I sometimes feel a bit (intermediately?) bad about as he’s just a dozy bugger rather than a Full arsehole, but it can’t be helped. -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
"Michael Black" wrote in message news:alpine.LNX.2.20.1810152215530.24529@thrush... On Mon, 15 Oct 2018, Jim GM4DHJ ... wrote: "Gareth's Downstairs Computer" wrote in message ... On 14/10/2018 23:14, Ralph Mowery wrote: I think the tests have gotten away from the technical part of ham radio and are now geared more to the operating practices. It is never too late to correct such an egregious mistake, for operating as such is CB Radio whereas Amateur / Ham Radio is a whole-life technical pursuit. I have been persuing an HRO500 since the 60's .......... I once saw a Galaxy R-530, a somewhat similar general coverage receiver, but from later in the sixties. All I'd ever seen was the ads, it was actually bigger than I expected. I have no idea how that landed in a local's hands, but I sort of knew the guy who bought it, and he seemed ahppy. This was about 20 years ago. Michael never seen any galaxy gear......still want an SX101A but they are too big my HRO500 is big enough...running out of space...have to sell some stuff..... |
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On 15/10/2018 16:45, Jeff Liebermann wrote:
On Mon, 15 Oct 2018 12:16:14 +0000, Spike wrote: On 15/10/2018 01:20, Jeff Liebermann wrote: On Sun, 14 Oct 2018 11:12:14 -0700, Jeff Liebermann wrote: Since you prefer a minimalist approach to test equipment, as an alternative to your light bulb, may I suggest a return loss bridge: https://www.google.com/search?q=return+loss+bridge&tbm=isch Note that there are several basic designs and configurations but all are fairly simple and easy to construct. Note that these are NOT the same as directional couplers. To use it, you need a minimum of an RF signal generator and a voltmeter or oscilloscope. I prefer to sweep the frequency range of interest, so I use an RF sweep generator, and display the result on an oscilloscope. With this arrangement, you can tune your antenna without requiring a light bulb. So, let me get this right. By employing a return-loss bridge, an RF signal generator, and either a voltmeter or an oscilloscope, you can get results that a distant station can't distinguish from those obtained by using a torch bulb? No. Per my previous rant, if your intent is "to be able to transmit signals intended to be received by another station", then a light bulb will suffice at producing the desired result. If your intent is to design the best possible antenna, then you'll need something better. If you just want to talk to someone, almost any kind of RF metering device is sufficient. There have been plenty of accounts of comparing various types of antennas. For example, PSK Reporter is a good way to perform such a test, where one can actually see the effects of antenna changes. https://pskreporter.info/pskmap.html What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control. A given antenna might be far superior under one set of condition, and rather disgusting under another. Most signal reports also tend to be very subjective, inaccurate, and not repeatable. If you are using a light built to tune a commercial antenna, which has already been optimized in extensive lab and field tests, I suspect that it is likely that a light bulb will give a similar result a proper VSWR measuring device. (Actually, that's not quite correct because I don't tune my antennas for minimum VSWR). However, that's not why someone purchases and uses a VNA or swept return loss bridge. They use these because they're building their own antenna, or optimizing a commercial antenna. Once the antenna has been properly tuned and tweaked, the VNA and return loss bridge are no longer needed unless something changes. Incidentally, I use a remote field strength meter to compare antennas. It has it's limitations, but it's better than using VSWR or maximum antenna current as in your light bulb method. Given your ability to estimate the performance of an antenna by looking at it rather than employ modelling methods, I would have though you would be sympathetic to the merits of the torch bulb approach. Since you seem impressed with my powers of observation, it might be useful to know that to the best of my limited knowledge, light bulbs went out of fashion in the 1930's, to be replaced by thermocouple antenna current meters. https://www.google.com/search?q=thermocouple+rf+ammeter&tbm=isch It is much easier to see changes in a meter deflection than changes in light bulb intensity, unless you also use a light meter. If you select different light bulbs for different power levels, you might be able to keep the losses to a minimum. In any case, a VNA or even a return loss bridge is not for you. There are plenty of things one can do with ham radio including "to be able to transmit signals intended to be received by another station". You seem intent on using the oldest and most crude methods of accomplishing this. That's fine as there is room for retro-radio, antique radio techniques, and preserving historical technology. I would guess(tm) that your radios all use tube (thermionic valves) and that you tune the transmitter for maximum cherry red glow in the finals. Best of luck, but that's not for me. Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
Spike wrote:
On 15/10/2018 16:45, Jeff Liebermann wrote: On Mon, 15 Oct 2018 12:16:14 +0000, Spike wrote: On 15/10/2018 01:20, Jeff Liebermann wrote: On Sun, 14 Oct 2018 11:12:14 -0700, Jeff Liebermann wrote: Since you prefer a minimalist approach to test equipment, as an alternative to your light bulb, may I suggest a return loss bridge: https://www.google.com/search?q=return+loss+bridge&tbm=isch Note that there are several basic designs and configurations but all are fairly simple and easy to construct. Note that these are NOT the same as directional couplers. To use it, you need a minimum of an RF signal generator and a voltmeter or oscilloscope. I prefer to sweep the frequency range of interest, so I use an RF sweep generator, and display the result on an oscilloscope. With this arrangement, you can tune your antenna without requiring a light bulb. So, let me get this right. By employing a return-loss bridge, an RF signal generator, and either a voltmeter or an oscilloscope, you can get results that a distant station can't distinguish from those obtained by using a torch bulb? No. Per my previous rant, if your intent is "to be able to transmit signals intended to be received by another station", then a light bulb will suffice at producing the desired result. If your intent is to design the best possible antenna, then you'll need something better. If you just want to talk to someone, almost any kind of RF metering device is sufficient. There have been plenty of accounts of comparing various types of antennas. For example, PSK Reporter is a good way to perform such a test, where one can actually see the effects of antenna changes. https://pskreporter.info/pskmap.html What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control. A given antenna might be far superior under one set of condition, and rather disgusting under another. Most signal reports also tend to be very subjective, inaccurate, and not repeatable. If you are using a light built to tune a commercial antenna, which has already been optimized in extensive lab and field tests, I suspect that it is likely that a light bulb will give a similar result a proper VSWR measuring device. (Actually, that's not quite correct because I don't tune my antennas for minimum VSWR). However, that's not why someone purchases and uses a VNA or swept return loss bridge. They use these because they're building their own antenna, or optimizing a commercial antenna. Once the antenna has been properly tuned and tweaked, the VNA and return loss bridge are no longer needed unless something changes. Incidentally, I use a remote field strength meter to compare antennas. It has it's limitations, but it's better than using VSWR or maximum antenna current as in your light bulb method. Given your ability to estimate the performance of an antenna by looking at it rather than employ modelling methods, I would have though you would be sympathetic to the merits of the torch bulb approach. Since you seem impressed with my powers of observation, it might be useful to know that to the best of my limited knowledge, light bulbs went out of fashion in the 1930's, to be replaced by thermocouple antenna current meters. https://www.google.com/search?q=thermocouple+rf+ammeter&tbm=isch It is much easier to see changes in a meter deflection than changes in light bulb intensity, unless you also use a light meter. If you select different light bulbs for different power levels, you might be able to keep the losses to a minimum. In any case, a VNA or even a return loss bridge is not for you. There are plenty of things one can do with ham radio including "to be able to transmit signals intended to be received by another station". You seem intent on using the oldest and most crude methods of accomplishing this. That's fine as there is room for retro-radio, antique radio techniques, and preserving historical technology. I would guess(tm) that your radios all use tube (thermionic valves) and that you tune the transmitter for maximum cherry red glow in the finals. Best of luck, but that's not for me. Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". #Waves -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
On 16/10/2018 08:08, Jeff wrote:
I'm fairly sure the SSB was generated at 9MHz. Googling for a reminder, I find a large number of 9MHz sideband crystal filters available, while nothing for 5MHz. Presumably, the 9MHz sideband crystal filter is use for both the receiver IF filter and in the exciter SSB generator to strip off the unwanted sideband. You are correct 9MHzwas a common IF for both tx & rx. A common way of generating both usb and lsb was to have 2 switched crystals with frequencies just above and below 9MHz in the oscillator, feeding a balanced mixer, before the xtal filter, and switch depending on which sideband you required. Is there a mathematician on here that can explain the maths of sideband inversion/retention? -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On 16/10/2018 09:14, Jeff wrote:
A common way of generating both usb and lsb was to have 2 switched crystals with frequencies just above and below 9MHz in the oscillator, feeding a balanced mixer, before the xtal filter, and switch depending on which sideband you required. Is there a mathematician on here that can explain the maths of sideband inversion/retention? No inversion is required with this method. If you feed a ~9MHz signal and audio into a balanced mixer the output will be both sidebands plus a suppressed carrier. Your xtal filter is ~2.4kHz wide centred on 9MHz, so if you move the frequency of the ~9Mhz signal (switch a crystal) going into the balanced mixer either above or below 9MHz you can select which side band goes through your filter. Simples. Wasn't a similar system used in the Yaesu FT-200 (9MHz IF, 5 MHz VFO)? IIRC the set had a NORM/INV sideband switch. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On 15/10/2018 20:42, Roger Hayter wrote:
wrote: Roger Hayter wrote: You say "none of us" - there are only three of you! Most group users don't particularly love Reay and his acolytes much more than Spike, I would think. I'd **** on Burt if he weren't on fire. Does that make you feel better, Rog? I'd also put a dog dirt through his letterbox. Quite so. But there are still only three of you. What did we do to deserve such tedious windbags? -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
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On Tue, 16 Oct 2018 14:18:56 +0000
Spike wrote: On 15/10/2018 20:42, Roger Hayter wrote: wrote: Roger Hayter wrote: You say "none of us" - there are only three of you! Most group users don't particularly love Reay and his acolytes much more than Spike, I would think. I'd **** on Burt if he weren't on fire. Does that make you feel better, Rog? I'd also put a dog dirt through his letterbox. Quite so. But there are still only three of you. What did we do to deserve such tedious windbags? Burt, you spent years of your life on Usenet being a horrible ****, Burt. Burt, Thanks, Burt. |
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On Tue, 16 Oct 2018 07:44:53 +0000, Spike
wrote: Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". Perhaps an analogy might be useful. Instead of an HF radio, you're dealing with your automobile. Under normal circumstances, it will get you to work and back fairly efficiently. However, you notice that your gasoline (petrol) mileage is not quite what you might expect. So, you have a choice of mechanics. The first mechanic tunes the engine with a light bulb, divining rod, magic incantations, and offers a rather bizarre description of what work was done on the vehicle. The second mechanic uses proper computerized test equipment to analyze the situation, uses factory parts, and delivers the car with a detailed printout of what was done, what changes were made, what parts were used, and a before-after gas mileage comparison performed on a dynamometer. Now, which mechanic would you prefer? Your car will still go to work and back in some manner. The second mechanic will cost more, because he has to pay for all the expensive equipment and genuine parts. If you're impoverished, obviously the first mechanic will be the only available choice, but assuming you plan to keep the vehicle, one might suspect it is a bad long term solution. From my perspective, both professional and as a ham, I deal in numbers. I can tell by looking at the numbers what is happening and what needs to be done. I have a small collection of aging test equipment to help me generate the numbers. Light bulbs do not generate numbers and are therefore (in my never humble opinion) useless and worthless. However, I will concede that if your intent is "to be able to transmit signals intended to be received by another station", a light bulb is sufficient to determine that your transmitter is spewing RF, spurs, harmonics, and noise into an antenna-like device that is either radiating the RF, absorbing it into heat, or reflecting it back to the transmitter (because the light bulb indicates the same in both directions). -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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On Tue, 16 Oct 2018, Spike wrote:
On 16/10/2018 09:14, Jeff wrote: A common way of generating both usb and lsb was to have 2 switched crystals with frequencies just above and below 9MHz in the oscillator, feeding a balanced mixer, before the xtal filter, and switch depending on which sideband you required. Is there a mathematician on here that can explain the maths of sideband inversion/retention? No inversion is required with this method. If you feed a ~9MHz signal and audio into a balanced mixer the output will be both sidebands plus a suppressed carrier. Your xtal filter is ~2.4kHz wide centred on 9MHz, so if you move the frequency of the ~9Mhz signal (switch a crystal) going into the balanced mixer either above or below 9MHz you can select which side band goes through your filter. Simples. Wasn't a similar system used in the Yaesu FT-200 (9MHz IF, 5 MHz VFO)? IIRC the set had a NORM/INV sideband switch. That wasn't uncommon, the conversion scheme allowing for the "default" sideband to be one switch position, so the only time you needed to switch sidebands was if you needed the "wrong" sideband". Michael |
4NEC2?
On Tue, 16 Oct 2018 13:22:28 -0400, Ralph Mowery
wrote: Again, it all depends on the mechanic. The computer tune may only get you a small improvement and it will take 5 years to make up the cost difference. I had a car that started running real bad. After the simple things I replaced like spark plugs, wires and coil, I looked on an Autozone page and one thing was a $ 500 sensor that may cause the problem. I took it to a dealer that should have all the proper equipment. After about 3 weeks he finally replaced that sensor and it fixed the problem. The part would have taken less than half an hour to replace. They may still have been working on it if I had not sent off a nice email to Toyota after a week and a half of no repair. I know of a case where a Freeze plug was leaking and the motor company wanted to pull the engine to get to it. Shade tree mechanic pulled back the carpet inside the car, took a hole saw and cut a hole in the firewall to get to the plug. Repaired the hole with a beer can and pop rivits for less than $ 100. All that you've shown is that an idiot with all the technology of modern electronics can screw things up, and that simple repairs can be done simply and cheaply by someone who has some experience. I'm talking about a given situation, which could be done with either a light bulb or a pile of test equipment. Not two different repair situations. So, let's take your blown $500 black box, presumably out of warranty. Would you take the problem to the shade tree mechanic with his beer can and pop rivet tool? What would you expect him to do? Drill open the black box and start replacing parts until it works? Would he offer a warranty? At best, he would find a similar black box at a scrap yard, box rebuider, or midnight auto, and sell it to you at a discount. Would you consider that acceptable? Let me bring it closer to home. You purchased an expensive HF radio with all the bells and whistles. It's out of warranty and you need something fixed. Would you send it to 1) the factory, 2) an authorized repair station, 3) a rebuilder in China, 4) the ham equivalent of the shade tree mechanic, or 5) the teenager next door? The distinction between these choices is a experience and training, but also access to the necessary test equipment and parts. Better yet, if you knew any of these used a light bulb to determine if your transmitter was working, and a "talk test" as QA, would you do business with them? No need to answer the questions. Just think about the implications. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
On 16/10/2018 14:38, Ralph Mowery wrote:
In article , lid says... Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". Sometimes it is who is doing the adjusting and not how good the equipment is. That's very true, of course. Some good equipment is in the 'wrong hands'. Almost 40 years ago I started keeping a repeater on the air that was started by someone else. My test equipment at that time was a VTVM, a $ 25 Heathkit signal generator, old Oscilloscope, swr meter, and frequency counter. To tune the receiver my best 'signal generator' was a ham near the edge of the repeater coverage. I would have him just to key down for a minute or two at a time while I adjusted the receiver. Over the years a better receiver and transmitter was installed. Now I have some very good test equipment, but can not say the coverage of the repeater is very much better. What little improvement is made is probably because the radio equipment is better. Thanks! That's just the sort of thing I was on about - in this case you actually used a distant station to help with the set-up, and it worked well. At that time one thing I did not try to adjust or check was the duplexer as I did not think I could with what I had to work with. Many years ago the tuning instructions for duplexers was to tune for maximum signal on the pass and best rejection. As test equipment became better and priced in range, the pass tuning change to using a return loss bridge and SA/TG. This seems to work much better. I found the pass was broad and you could usually give the tuning rod a turn or two without much effect, but he RLB shows up in less than 1/2 of a turn. Does it make a difference ? Probably not in effective coverage (it may extend the range a foot or two,hi), but at least I know it tuned the best it can be with what I have to work with. One thing that does come with better test equipment is knowing that the equipment is tuned so it meets or exceeds the specifications. Before it was just a guess as if the equipment did or did not meet specifications. Quite so. But 'specifications' are often written with other things in mind - compatibility, spurii, stability, etc, and not necessarily anything at all to do with how the distant station receives/perceives one's signal. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On 16/10/2018 20:47, Jeff Liebermann wrote:
Let me bring it closer to home. You purchased an expensive HF radio with all the bells and whistles. It's out of warranty and you need something fixed. Would you send it to 1) the factory, 2) an authorized repair station, 3) a rebuilder in China, 4) the ham equivalent of the shade tree mechanic, or 5) the teenager next door? If you send to anyone other than yourself then you are not a real radio ham or radio amateur. A CBer, probably. |
4NEC2?
On 16/10/2018 16:17, Jeff Liebermann wrote:
On Tue, 16 Oct 2018 07:44:53 +0000, Spike wrote: Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". Perhaps an analogy might be useful. Instead of an HF radio, you're dealing with your automobile. Under normal circumstances, it will get you to work and back fairly efficiently. However, you notice that your gasoline (petrol) mileage is not quite what you might expect. So, you have a choice of mechanics. The first mechanic tunes the engine with a light bulb, divining rod, magic incantations, and offers a rather bizarre description of what work was done on the vehicle. The second mechanic uses proper computerized test equipment to analyze the situation, uses factory parts, and delivers the car with a detailed printout of what was done, what changes were made, what parts were used, and a before-after gas mileage comparison performed on a dynamometer. Now, which mechanic would you prefer? Your car will still go to work and back in some manner. The second mechanic will cost more, because he has to pay for all the expensive equipment and genuine parts. If you're impoverished, obviously the first mechanic will be the only available choice, but assuming you plan to keep the vehicle, one might suspect it is a bad long term solution. From my perspective, both professional and as a ham, I deal in numbers. I can tell by looking at the numbers what is happening and what needs to be done. I have a small collection of aging test equipment to help me generate the numbers. Light bulbs do not generate numbers and are therefore (in my never humble opinion) useless and worthless. They don't need to generate numbers! I can think of at least one method, using light bulbs, that will get a pretty accurate measurement of power, and if you want, balance, in a system. The distant station, of course, knows nothing of this, and couldn't tell whether I'd used the 'numbers' of your method or the analogue approach of mine. However, I will concede that if your intent is "to be able to transmit signals intended to be received by another station", a light bulb is sufficient to determine that your transmitter is spewing RF, spurs, harmonics, and noise into an antenna-like device that is either radiating the RF, absorbing it into heat, or reflecting it back to the transmitter (because the light bulb indicates the same in both directions). But the people your imaginary friend works for care for none of this, as his car gets him to work on time. To bring this back to the issue at hand, I claimed that "I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA" and so far that still stands. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On 17/10/2018 08:51, Spike wrote:
To bring this back to the issue at hand, I claimed that "I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA" and so far that still stands. With all his blustering and gratuitous personal abuse, Lieberman presents as the Yank version of M3OSN. |
4NEC2?
Spike wrote:
On 16/10/2018 14:38, Ralph Mowery wrote: In article , lid says... Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". Sometimes it is who is doing the adjusting and not how good the equipment is. That's very true, of course. Some good equipment is in the 'wrong hands'. Almost 40 years ago I started keeping a repeater on the air that was started by someone else. My test equipment at that time was a VTVM, a $ 25 Heathkit signal generator, old Oscilloscope, swr meter, and frequency counter. To tune the receiver my best 'signal generator' was a ham near the edge of the repeater coverage. I would have him just to key down for a minute or two at a time while I adjusted the receiver. Over the years a better receiver and transmitter was installed. Now I have some very good test equipment, but can not say the coverage of the repeater is very much better. What little improvement is made is probably because the radio equipment is better. Thanks! That's just the sort of thing I was on about - in this case you actually used a distant station to help with the set-up, and it worked well. At that time one thing I did not try to adjust or check was the duplexer as I did not think I could with what I had to work with. Many years ago the tuning instructions for duplexers was to tune for maximum signal on the pass and best rejection. As test equipment became better and priced in range, the pass tuning change to using a return loss bridge and SA/TG. This seems to work much better. I found the pass was broad and you could usually give the tuning rod a turn or two without much effect, but he RLB shows up in less than 1/2 of a turn. Does it make a difference ? Probably not in effective coverage (it may extend the range a foot or two,hi), but at least I know it tuned the best it can be with what I have to work with. One thing that does come with better test equipment is knowing that the equipment is tuned so it meets or exceeds the specifications. Before it was just a guess as if the equipment did or did not meet specifications. Quite so. But 'specifications' are often written with other things in mind - compatibility, spurii, stability, etc, and not necessarily anything at all to do with how the distant station receives/perceives one's signal. ISTR it being a licence condition that one checked all the above periodically - more honoured in the breach, perhaps, with commercial kit. -- Roger Hayter |
4NEC2?
Jeff Liebermann wrote:
On Tue, 16 Oct 2018 07:44:53 +0000, Spike wrote: Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". Perhaps an analogy might be useful. Instead of an HF radio, you're dealing with your automobile. Under normal circumstances, it will get you to work and back fairly efficiently. However, you notice that your gasoline (petrol) mileage is not quite what you might expect. So, you have a choice of mechanics. The first mechanic tunes the engine with a light bulb, divining rod, magic incantations, and offers a rather bizarre description of what work was done on the vehicle. The second mechanic uses proper computerized test equipment to analyze the situation, uses factory parts, and delivers the car with a detailed printout of what was done, what changes were made, what parts were used, and a before-after gas mileage comparison performed on a dynamometer. Now, which mechanic would you prefer? Your car will still go to work and back in some manner. The second mechanic will cost more, because he has to pay for all the expensive equipment and genuine parts. If you're impoverished, obviously the first mechanic will be the only available choice, but assuming you plan to keep the vehicle, one might suspect it is a bad long term solution. From my perspective, both professional and as a ham, I deal in numbers. I can tell by looking at the numbers what is happening and what needs to be done. I have a small collection of aging test equipment to help me generate the numbers. Light bulbs do not generate numbers and are therefore (in my never humble opinion) useless and worthless. However, I will concede that if your intent is "to be able to transmit signals intended to be received by another station", a light bulb is sufficient to determine that your transmitter is spewing RF, spurs, harmonics, and noise into an antenna-like device that is either radiating the RF, absorbing it into heat, or reflecting it back to the transmitter (because the light bulb indicates the same in both directions). Burt won’t appreciate being given an absolute schooling from Jeff here. -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
Gareth's Downstairs Computer
wrote: On 16/10/2018 20:47, Jeff Liebermann wrote: Let me bring it closer to home. You purchased an expensive HF radio with all the bells and whistles. It's out of warranty and you need something fixed. Would you send it to 1) the factory, 2) an authorized repair station, 3) a rebuilder in China, 4) the ham equivalent of the shade tree mechanic, or 5) the teenager next door? If you send to anyone other than yourself then you are not a real radio ham or radio amateur. A CBer, probably. G is for gurgler. -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
On 17/10/2018 10:00, Roger Hayter wrote:
Spike wrote: On 16/10/2018 14:38, Ralph Mowery wrote: In article , lid says... Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". Sometimes it is who is doing the adjusting and not how good the equipment is. That's very true, of course. Some good equipment is in the 'wrong hands'. Almost 40 years ago I started keeping a repeater on the air that was started by someone else. My test equipment at that time was a VTVM, a $ 25 Heathkit signal generator, old Oscilloscope, swr meter, and frequency counter. To tune the receiver my best 'signal generator' was a ham near the edge of the repeater coverage. I would have him just to key down for a minute or two at a time while I adjusted the receiver. Over the years a better receiver and transmitter was installed. Now I have some very good test equipment, but can not say the coverage of the repeater is very much better. What little improvement is made is probably because the radio equipment is better. Thanks! That's just the sort of thing I was on about - in this case you actually used a distant station to help with the set-up, and it worked well. At that time one thing I did not try to adjust or check was the duplexer as I did not think I could with what I had to work with. Many years ago the tuning instructions for duplexers was to tune for maximum signal on the pass and best rejection. As test equipment became better and priced in range, the pass tuning change to using a return loss bridge and SA/TG. This seems to work much better. I found the pass was broad and you could usually give the tuning rod a turn or two without much effect, but he RLB shows up in less than 1/2 of a turn. Does it make a difference ? Probably not in effective coverage (it may extend the range a foot or two,hi), but at least I know it tuned the best it can be with what I have to work with. One thing that does come with better test equipment is knowing that the equipment is tuned so it meets or exceeds the specifications. Before it was just a guess as if the equipment did or did not meet specifications. Quite so. But 'specifications' are often written with other things in mind - compatibility, spurii, stability, etc, and not necessarily anything at all to do with how the distant station receives/perceives one's signal. ISTR it being a licence condition that one checked all the above periodically - more honoured in the breach, perhaps, with commercial kit. That's the sort of road that Liebermann wanted to take the discussion down; an interesting topic but not the issue under discussion. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
Stephen Thomas Cole wrote:
Jeff Liebermann wrote: On Tue, 16 Oct 2018 07:44:53 +0000, Spike wrote: Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". Perhaps an analogy might be useful. Instead of an HF radio, you're dealing with your automobile. Under normal circumstances, it will get you to work and back fairly efficiently. However, you notice that your gasoline (petrol) mileage is not quite what you might expect. So, you have a choice of mechanics. The first mechanic tunes the engine with a light bulb, divining rod, magic incantations, and offers a rather bizarre description of what work was done on the vehicle. The second mechanic uses proper computerized test equipment to analyze the situation, uses factory parts, and delivers the car with a detailed printout of what was done, what changes were made, what parts were used, and a before-after gas mileage comparison performed on a dynamometer. Now, which mechanic would you prefer? Your car will still go to work and back in some manner. The second mechanic will cost more, because he has to pay for all the expensive equipment and genuine parts. If you're impoverished, obviously the first mechanic will be the only available choice, but assuming you plan to keep the vehicle, one might suspect it is a bad long term solution. From my perspective, both professional and as a ham, I deal in numbers. I can tell by looking at the numbers what is happening and what needs to be done. I have a small collection of aging test equipment to help me generate the numbers. Light bulbs do not generate numbers and are therefore (in my never humble opinion) useless and worthless. However, I will concede that if your intent is "to be able to transmit signals intended to be received by another station", a light bulb is sufficient to determine that your transmitter is spewing RF, spurs, harmonics, and noise into an antenna-like device that is either radiating the RF, absorbing it into heat, or reflecting it back to the transmitter (because the light bulb indicates the same in both directions). Burt won't appreciate being given an absolute schooling from Jeff here. I don't appreciate an interesting discussion being interpreted as a schoolyard fight by ignorant troublemakers like you and Gareth. -- Roger Hayter |
4NEC2?
"Roger Hayter" wrote in message ... Stephen Thomas Cole wrote: Jeff Liebermann wrote: On Tue, 16 Oct 2018 07:44:53 +0000, Spike wrote: Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". Perhaps an analogy might be useful. Instead of an HF radio, you're dealing with your automobile. Under normal circumstances, it will get you to work and back fairly efficiently. However, you notice that your gasoline (petrol) mileage is not quite what you might expect. So, you have a choice of mechanics. The first mechanic tunes the engine with a light bulb, divining rod, magic incantations, and offers a rather bizarre description of what work was done on the vehicle. The second mechanic uses proper computerized test equipment to analyze the situation, uses factory parts, and delivers the car with a detailed printout of what was done, what changes were made, what parts were used, and a before-after gas mileage comparison performed on a dynamometer. Now, which mechanic would you prefer? Your car will still go to work and back in some manner. The second mechanic will cost more, because he has to pay for all the expensive equipment and genuine parts. If you're impoverished, obviously the first mechanic will be the only available choice, but assuming you plan to keep the vehicle, one might suspect it is a bad long term solution. From my perspective, both professional and as a ham, I deal in numbers. I can tell by looking at the numbers what is happening and what needs to be done. I have a small collection of aging test equipment to help me generate the numbers. Light bulbs do not generate numbers and are therefore (in my never humble opinion) useless and worthless. However, I will concede that if your intent is "to be able to transmit signals intended to be received by another station", a light bulb is sufficient to determine that your transmitter is spewing RF, spurs, harmonics, and noise into an antenna-like device that is either radiating the RF, absorbing it into heat, or reflecting it back to the transmitter (because the light bulb indicates the same in both directions). Burt won't appreciate being given an absolute schooling from Jeff here. I don't appreciate an interesting discussion being interpreted as a schoolyard fight by ignorant troublemakers like you and Gareth. what was interesting about it ?..... |
4NEC2?
On 17/10/2018 14:20, Jim GM4DHJ ... wrote:
"Roger Hayter" wrote in message Stephen Thomas Cole wrote: Jeff Liebermann wrote: On Tue, 16 Oct 2018 07:44:53 +0000, Spike wrote: Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". Perhaps an analogy might be useful. Instead of an HF radio, you're dealing with your automobile. Under normal circumstances, it will get you to work and back fairly efficiently. However, you notice that your gasoline (petrol) mileage is not quite what you might expect. So, you have a choice of mechanics. The first mechanic tunes the engine with a light bulb, divining rod, magic incantations, and offers a rather bizarre description of what work was done on the vehicle. The second mechanic uses proper computerized test equipment to analyze the situation, uses factory parts, and delivers the car with a detailed printout of what was done, what changes were made, what parts were used, and a before-after gas mileage comparison performed on a dynamometer. Now, which mechanic would you prefer? Your car will still go to work and back in some manner. The second mechanic will cost more, because he has to pay for all the expensive equipment and genuine parts. If you're impoverished, obviously the first mechanic will be the only available choice, but assuming you plan to keep the vehicle, one might suspect it is a bad long term solution. From my perspective, both professional and as a ham, I deal in numbers. I can tell by looking at the numbers what is happening and what needs to be done. I have a small collection of aging test equipment to help me generate the numbers. Light bulbs do not generate numbers and are therefore (in my never humble opinion) useless and worthless. However, I will concede that if your intent is "to be able to transmit signals intended to be received by another station", a light bulb is sufficient to determine that your transmitter is spewing RF, spurs, harmonics, and noise into an antenna-like device that is either radiating the RF, absorbing it into heat, or reflecting it back to the transmitter (because the light bulb indicates the same in both directions). Burt won't appreciate being given an absolute schooling from Jeff here. I don't appreciate an interesting discussion being interpreted as a schoolyard fight by ignorant troublemakers like you and Gareth. what was interesting about it ?..... The clash of cultures between the open-minded out-of-the-box thinker, and a rules-and-regulations-trump-everything engineer. We have the latter type on UKRA too, more's the pity. Then there's those that don't know a sideband from a sideburn, waving their 'Vouvray for our side' banners. In all senses of the word. -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On Wed, 17 Oct 2018 08:48:04 +0100, Gareth's Downstairs Computer
wrote: On 16/10/2018 20:47, Jeff Liebermann wrote: Let me bring it closer to home. You purchased an expensive HF radio with all the bells and whistles. It's out of warranty and you need something fixed. Would you send it to 1) the factory, 2) an authorized repair station, 3) a rebuilder in China, 4) the ham equivalent of the shade tree mechanic, or 5) the teenager next door? If you send to anyone other than yourself then you are not a real radio ham or radio amateur. Are you suggesting that you have the ability to repair a modern HF radio? Do you have the equipment? Do you have the knowledge? I have both and believe me, it's often very difficult. Today's electronics is not made to be easily repaired. Much of the stuff I fix was sent to me after some ham attempted to fix it themselves. Usually, they won't admit it. On the repair bench right now is an Astron power supply, an MFJ-259 antenna analyzer, two HP5300 series counters, and unfortunately, my IFR-1500 service monitor. All of them are the results of botched repairs. Can you do better? After you fail, which of the above 5 choices would be your next step? Or would you just sell the radio and pretend there was nothing wrong? A CBer, probably. It's interesting that all of your brilliant pontifications include a derogatory comment about CB'ers. That's odd because I've always assumed that you are a CB'er or at least own and use a CB radio. Is that true? Is it possible for you to write something without mentioning CB or insulting the reader in some manner? Judging by your past history, I doubt it. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
On Wed, 17 Oct 2018 10:36:45 +0000, Spike
wrote: That's the sort of road that Liebermann wanted to take the discussion down; an interesting topic but not the issue under discussion. Guilty as charged. I do tend to divert discussions in directions that I find interesting. After all, why bother writing a long rant that nobody will read? One-line pontifications, or the all too common SMS/chat messaging method of discussion are terminally boring, and rarely produce anything worth reading. The lack of substantiation, references, and detail found in such short comments offer little in the way of an education, unless refining one's skill at delivering insults is considered educational. I've tried to adopt a policy of only writing and posting things that I think might be worth reading. That which is unlikely to be of general interest, I don't bother posting. If everyone followed such a policy, the various newsgroups would be much more pleasant and interesting to read. Anyway, I would rant some more, but I'm late for an exercise trudge in the local state park followed by a lunch meeting with the local hams. More rants later, if I survive. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
On 17/10/2018 16:00, Jeff Liebermann wrote:
On Wed, 17 Oct 2018 08:48:04 +0100, Gareth's Downstairs Computer wrote: On 16/10/2018 20:47, Jeff Liebermann wrote: Let me bring it closer to home. You purchased an expensive HF radio with all the bells and whistles. It's out of warranty and you need something fixed. Would you send it to 1) the factory, 2) an authorized repair station, 3) a rebuilder in China, 4) the ham equivalent of the shade tree mechanic, or 5) the teenager next door? If you send to anyone other than yourself then you are not a real radio ham or radio amateur. Are you suggesting that you have the ability to repair a modern HF radio? Yes Do you have the equipment? Yes Do you have the knowledge? Yes I have both and believe me, it's often very difficult. Best deal with someone else who is competent, then. Today's electronics is not made to be easily repaired. Best deal with someone else who is competent, then. Much of the stuff I fix was sent to me after some ham attempted to fix it themselves. Usually, they won't admit it. On the repair bench right now is an Astron power supply, an MFJ-259 antenna analyzer, two HP5300 series counters, and unfortunately, my IFR-1500 service monitor. All of them are the results of botched repairs. Can you do better? Yes. Send them to me with prepaid return packaging. After you fail, which of the above 5 choices would be your next step? I don't fail, so your question has no meaning. Or would you just sell the radio and pretend there was nothing wrong? That's your train of thought but not mine. A CBer, probably. It's interesting that all of your brilliant pontifications include a derogatory comment about CB'ers. I don't make derogatory comments about CBers but I do distinguish the operating hobby which is CB Radio and the whole-life technical pursuit that is amateur radio. CBers in their own world are harmless until they try to pass themselves off as radio amateurs. That's odd because I've always assumed that you are a CB'er or at least own and use a CB radio. Your modus operandi is to be rude, which is why you are largely passed over without even being read. Is that true? I am not in a position to determine that what you said is what you assumed. Is it possible for you to write something without mentioning CB or insulting the reader in some manner? I do not insult my readership. That is your habit. Judging by your past history, I doubt it. Your habit. QED. |
4NEC2?
Roger Hayter wrote:
Stephen Thomas Cole wrote: Jeff Liebermann wrote: On Tue, 16 Oct 2018 07:44:53 +0000, Spike wrote: Very interesting, but I'd have to say that none of what you say refutes my original contention that the distant station, which after all is the one we are trying to communicate with, will notice any difference to the received signal whether the sending station's antenna was tuned with a 20c torch bulb or a $300 VNA. You touched on the main vagaries of the system when you said "What I've found is that such side by side comparisons do not account for variations in propagation, path, interference, local noise, time of day, position of the moon, and other factors beyond the operators control". Perhaps an analogy might be useful. Instead of an HF radio, you're dealing with your automobile. Under normal circumstances, it will get you to work and back fairly efficiently. However, you notice that your gasoline (petrol) mileage is not quite what you might expect. So, you have a choice of mechanics. The first mechanic tunes the engine with a light bulb, divining rod, magic incantations, and offers a rather bizarre description of what work was done on the vehicle. The second mechanic uses proper computerized test equipment to analyze the situation, uses factory parts, and delivers the car with a detailed printout of what was done, what changes were made, what parts were used, and a before-after gas mileage comparison performed on a dynamometer. Now, which mechanic would you prefer? Your car will still go to work and back in some manner. The second mechanic will cost more, because he has to pay for all the expensive equipment and genuine parts. If you're impoverished, obviously the first mechanic will be the only available choice, but assuming you plan to keep the vehicle, one might suspect it is a bad long term solution. From my perspective, both professional and as a ham, I deal in numbers. I can tell by looking at the numbers what is happening and what needs to be done. I have a small collection of aging test equipment to help me generate the numbers. Light bulbs do not generate numbers and are therefore (in my never humble opinion) useless and worthless. However, I will concede that if your intent is "to be able to transmit signals intended to be received by another station", a light bulb is sufficient to determine that your transmitter is spewing RF, spurs, harmonics, and noise into an antenna-like device that is either radiating the RF, absorbing it into heat, or reflecting it back to the transmitter (because the light bulb indicates the same in both directions). Burt won't appreciate being given an absolute schooling from Jeff here. I don't appreciate an interesting discussion being interpreted as a schoolyard fight by ignorant troublemakers like you and Gareth. I couldn’t give a **** what you don’t appreciate, Rog. HTH. Vote Steve! -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
Jeff Liebermann wrote:
On Wed, 17 Oct 2018 08:48:04 +0100, Gareth's Downstairs Computer wrote: On 16/10/2018 20:47, Jeff Liebermann wrote: Let me bring it closer to home. You purchased an expensive HF radio with all the bells and whistles. It's out of warranty and you need something fixed. Would you send it to 1) the factory, 2) an authorized repair station, 3) a rebuilder in China, 4) the ham equivalent of the shade tree mechanic, or 5) the teenager next door? If you send to anyone other than yourself then you are not a real radio ham or radio amateur. Are you suggesting that you have the ability to repair a modern HF radio? He’s got a track record of not even being able to tune up an FT101 because his copy of the manual was missing the relevant pages. Do you have the equipment? Do you have the knowledge? I have both and believe me, it's often very difficult. Today's electronics is not made to be easily repaired. Much of the stuff I fix was sent to me after some ham attempted to fix it themselves. Usually, they won't admit it. On the repair bench right now is an Astron power supply, an MFJ-259 antenna analyzer, two HP5300 series counters, and unfortunately, my IFR-1500 service monitor. All of them are the results of botched repairs. Can you do better? After you fail, which of the above 5 choices would be your next step? Or would you just sell the radio and pretend there was nothing wrong? A CBer, probably. It's interesting that all of your brilliant pontifications include a derogatory comment about CB'ers. That's odd because I've always assumed that you are a CB'er or at least own and use a CB radio. Is that true? Is it possible for you to write something without mentioning CB or insulting the reader in some manner? Judging by your past history, I doubt it. Gareth tried CB once but botched the install in his car so badly his signal couldn’t get even a quarter mile away. It’s all in the archives. -- STC / M0TEY / http://twitter.com/ukradioamateur |
4NEC2?
On Wed, 17 Oct 2018, Gareth's Downstairs Computer wrote:
On 16/10/2018 20:47, Jeff Liebermann wrote: Let me bring it closer to home. You purchased an expensive HF radio with all the bells and whistles. It's out of warranty and you need something fixed. Would you send it to 1) the factory, 2) an authorized repair station, 3) a rebuilder in China, 4) the ham equivalent of the shade tree mechanic, or 5) the teenager next door? If you send to anyone other than yourself then you are not a real radio ham or radio amateur. A CBer, probably. Except you've built a lot of equipment, and know the theory well. Maybe you bought one of those fancy rigs that include 50/144/432 so you can go to a mountaintop so easily and work DX when the band is open. Way more portable thant equipment from fifty years ago, and it covers all bands (though maybe not the newer LF bands). Your experimentation is in following and observing propaganda. And if you just spent a lot of money on that rig, you might hesitate because it's small and expensive, rather than because you don't understand the circuitry, I know I'm tempted, 46 years after I was licensed, some money I could spend on it when I've never bought a new rig (or anything much in the way of used rigs) over the decades. I like the idea of a portable rig, and I like the idea of it being all bands, because I am way more interested in VHF and UHF SSB than HF. I know I drooled over the ICOM portables from the seventies, they had a line that included a 2M FM rig, but also 6M SSB and 2M SSB, and I think one for 432. Compact and portable and low power. You can't expect much from an SSB VHF rig unless you're expecting to do something esoteric with it, like DX or satellite work. YOu are endlessly trying to set up a classification system that would never really let many in. The only person I knew that had a COllins rig was the guy who ran the local code & theory class for decades, who was very much into the technical end of the hobby and lamented when the rules changed so the one couldn't build a transmitter with the entry level license. There's no contradiction, he had his rig and he fixed it when necessary, but he also build things and kept up with the technical end of the hobby. Michael |
4NEC2?
On 17/10/2018 20:44, Michael Black wrote:
YOu are endlessly trying to set up a classification system that would never really let many in. Untrue, all those truly self-motivated technically are welcomed. Amateur radio has privileges to be jealously guarded and is not now, nor has it ever been, a numbers game to increase bums on seats. |
4NEC2?
On Wed, 17 Oct 2018 08:00:55 -0700, Jeff Liebermann
wrote: On Wed, 17 Oct 2018 08:48:04 +0100, Gareth's Downstairs Computer m wrote: On 16/10/2018 20:47, Jeff Liebermann wrote: Let me bring it closer to home. You purchased an expensive HF radio with all the bells and whistles. It's out of warranty and you need something fixed. Would you send it to 1) the factory, 2) an authorized repair station, 3) a rebuilder in China, 4) the ham equivalent of the shade tree mechanic, or 5) the teenager next door? If you send to anyone other than yourself then you are not a real radio ham or radio amateur. Are you suggesting that you have the ability to repair a modern HF radio? Do you have the equipment? Do you have the knowledge? I have both and believe me, it's often very difficult. Today's electronics is not made to be easily repaired. Much of the stuff I fix was sent to me after some ham attempted to fix it themselves. Usually, they won't admit it. On the repair bench right now is an Astron power supply, an MFJ-259 antenna analyzer, two HP5300 series counters, Which ones, if you don't mind my asking? |
4NEC2?
On Wed, 17 Oct 2018 20:55:22 +0100, Custos Custodum
wrote: On Wed, 17 Oct 2018 08:00:55 -0700, Jeff Liebermann wrote: Much of the stuff I fix was sent to me after some ham attempted to fix it themselves. Usually, they won't admit it. On the repair bench right now is an Astron power supply, an MFJ-259 antenna analyzer, two HP5300 series counters, Which ones, if you don't mind my asking? I'm now sure what you mean by "which ones" so I'll detail all that I have in the queue. 1. Astron VS-35m. On arrival, it has all 4 pass transistors blown, the 723CN regulator blown, two 1N4002 diodes shorted, and a 2N3906 shorted. That left a TIP29 transistor and an MCR225 SCR, which I've elected to replace instead of test. I don't know what caused all the damage but I'll confess to blowing up the 723CN regulator by plugging it into the IC socket backwards. 2. Yet another MJF-259 to repair. I posted a web page on how to fix these after the input bridge is blown up. It's easy to blow and doesn't even require a transmitter. You can easily do it with just a static discharge to the coax connector center pin. http://www.learnbydestroying.com/jeffl/MFJ-269-repair/ The one I'm trying to repair is an early model and has the usual blown RF shottky input diodes, with some water damage, leaky battery damage, and the chronic crappy MFJ soldering on the ribbon cables. Note that the needed diodes are discontinued and are becoming difficult to find. I just ordered 100pcs on eBay. The repair will be easy enough, but the subsequent calibration is a real time burner. The owner has graciously offered to do the work if he could do it at my shop as he's lacking in some of the needed test equipment. https://www.mfjenterprises.com/MFJ-259Bcalibration.php (not so good) https://www.w8ji.com/mfj-259b_calibration.htm (more better) 3. There are now three counters in the queue. One HP5300A counter with HP5302A 50MHz universal counter front end. Two HP5300B counter with HP5308A 75MHz timer/counter front end https://picclick.com/HEWLETT-PACKARD-MEASURING-SYSTEM-5300B-HP-50MHz-Universal-123106839896.html I also have motley assortment of D/A, DC power, and plotter interface. They all work except the batteries in the DC supply should be replaced. All the counter sections seem to have the same problems. There electrolytics in the AC supply show high ESR and all the rotary switch contacts are tarnished. I just slopped some mineral oil and oleic acid mix on one of the switches. The contacts look clean and there are no more bad connections. I'll wash off the acid tomorrow so that none of the nearby copper becomes corroded. I just ordered some substitute electrolytics on eBay. Looking around the shop, there's quite a bit of additional test equipment that could use my attention. Most of it is not worth the time but I do it anyway. For example, three sweep generators: http://www.learnbydestroying.com/jeffl/pics/home/slides/BL-shop5.html There also a bunch of big linear power supplies that probably need new electrolytics. My IFR-1500 has a blown power supply that I can't seem to fix. I thought I had it fixed in 2010, but it died again in 2015: http://www.learnbydestroying.com/jeffl/IFR-1500%20Power%20Supply%20Repair/IFR-1500%20power%20supply%20repair.html Does that answer your question? -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
On Wed, 17 Oct 2018 14:32:20 +0000, Spike
wrote: The clash of cultures between the open-minded out-of-the-box thinker, and a rules-and-regulations-trump-everything engineer. We have the latter type on UKRA too, more's the pity. Then there's those that don't know a sideband from a sideburn, waving their 'Vouvray for our side' banners. In all senses of the word. I guess it's too late to put you back into your box. Yes, I'm one of those rules-n-regs types. I've even been involved in manufacturing a few standards. Since you have an open mind, I hope you don't mind if I pour some reasons why we have rules-n-regs into your wide open mind. In order to talk with someone via radio, you don't really need rules. You could simply build or buy something that generates and detects RF, attach a modulator, and now you're talking. The necessary ingredients are commonly available and fairly inexpensive. Not much more than a frequency counter or frequency standard are required so that you and your accomplice are both on the same frequency. Tuning with a light bulb is perfectly functional and will probably help with the tuning. However, there's a problem. You and your accomplice are not the only people on the air. There are others that also want to communicate with their friends and find that spurious crap belched by badly designed, badly constructed, or mis-adjusted transmitters are making their communications rather difficult. Similarly, your ability to receive transmissions from your accomplice might be limited by the spurious junk produced by the other users of the spectrum. Therefore, it would helpful if your receiver was somewhat tolerant to intermod, overload, blocking, adjacent channel, spurious responses, and other anomalies. In order to insure a minimum level of quality, the various regulatory agencies produce specifications and testing procedures. In other words, they produce numbers. Manufacturers and builders of radios are expected to test their products to those standards and fix anything that fails to comply. If everyone complies, then there's a good chance that you and your accomplice will be able to communicate without either transmitting or receiving any interference. Like you, I once had an open mind when it came to radio regulations. At the time, I was designing marine VHF FM radios. I was faced with a blocking (receiver overload) specification that was almost impossible. The interfering signal was so high that my test equipment could not produce the level required. I calculated that the interfering station antenna would need to be about 2 ft (60 cm) from my radio antenna to produce the required interference level. My open mind declared that to be ridiculous. I protested the specification and waited. In the return mail (this was before email), I received several photos of typical marine masts, yardarms, and towers, showing dual watch VHF antennas about 2ft away from each other. Oops. It was a real problem that required the radio to meet the specification. Obviously, all these specifications ultimately manifest themselves in the form or numbers. You'll find them all over the various FCC and Ofcom rules-n-regs. They're there to insure that you, your accomplice, and other users can communicate without mutual interference. There is no other way to insure reliable communications without measurements and test equipment. So, how do you make an RF tuning light bulb produce numbers? A light meter? -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
4NEC2?
On 18/10/2018 01:35, Jeff Liebermann wrote:
On Wed, 17 Oct 2018 14:32:20 +0000, Spike wrote: The clash of cultures between the open-minded out-of-the-box thinker, and a rules-and-regulations-trump-everything engineer. We have the latter type on UKRA too, more's the pity. Then there's those that don't know a sideband from a sideburn, waving their 'Vouvray for our side' banners. In all senses of the word. I guess it's too late to put you back into your box. Yes, I'm one of those rules-n-regs types. I've even been involved in manufacturing a few standards. Since you have an open mind, I hope you don't mind if I pour some reasons why we have rules-n-regs into your wide open mind. diversion into a side-topic snipped So, how do you make an RF tuning light bulb produce numbers? A light meter? By calculation, old boy, by calculation. Don't you do calculations in the US? -- Spike "Nearly all men can stand adversity, but if you want to test a man's character, give him an internet group to manage" |
4NEC2?
On Wed, 17 Oct 2018 17:01:33 -0700, Jeff Liebermann
wrote: On Wed, 17 Oct 2018 20:55:22 +0100, Custos Custodum wrote: On Wed, 17 Oct 2018 08:00:55 -0700, Jeff Liebermann wrote: Much of the stuff I fix was sent to me after some ham attempted to fix it themselves. Usually, they won't admit it. On the repair bench right now is an Astron power supply, an MFJ-259 antenna analyzer, two HP5300 series counters, Which ones, if you don't mind my asking? I'm now sure what you mean by "which ones" so I'll detail all that I have in the queue. 1. Astron VS-35m. On arrival, it has all 4 pass transistors blown, the 723CN regulator blown, two 1N4002 diodes shorted, and a 2N3906 shorted. That left a TIP29 transistor and an MCR225 SCR, which I've elected to replace instead of test. I don't know what caused all the damage but I'll confess to blowing up the 723CN regulator by plugging it into the IC socket backwards. 2. Yet another MJF-259 to repair. I posted a web page on how to fix these after the input bridge is blown up. It's easy to blow and doesn't even require a transmitter. You can easily do it with just a static discharge to the coax connector center pin. http://www.learnbydestroying.com/jeffl/MFJ-269-repair/ The one I'm trying to repair is an early model and has the usual blown RF shottky input diodes, with some water damage, leaky battery damage, and the chronic crappy MFJ soldering on the ribbon cables. Note that the needed diodes are discontinued and are becoming difficult to find. I just ordered 100pcs on eBay. The repair will be easy enough, but the subsequent calibration is a real time burner. The owner has graciously offered to do the work if he could do it at my shop as he's lacking in some of the needed test equipment. https://www.mfjenterprises.com/MFJ-259Bcalibration.php (not so good) https://www.w8ji.com/mfj-259b_calibration.htm (more better) 3. There are now three counters in the queue. One HP5300A counter with HP5302A 50MHz universal counter front end. Two HP5300B counter with HP5308A 75MHz timer/counter front end https://picclick.com/HEWLETT-PACKARD-MEASURING-SYSTEM-5300B-HP-50MHz-Universal-123106839896.html I also have motley assortment of D/A, DC power, and plotter interface. They all work except the batteries in the DC supply should be replaced. All the counter sections seem to have the same problems. There electrolytics in the AC supply show high ESR and all the rotary switch contacts are tarnished. I just slopped some mineral oil and oleic acid mix on one of the switches. The contacts look clean and there are no more bad connections. I'll wash off the acid tomorrow so that none of the nearby copper becomes corroded. I just ordered some substitute electrolytics on eBay. Looking around the shop, there's quite a bit of additional test equipment that could use my attention. Most of it is not worth the time but I do it anyway. For example, three sweep generators: http://www.learnbydestroying.com/jeffl/pics/home/slides/BL-shop5.html There also a bunch of big linear power supplies that probably need new electrolytics. My IFR-1500 has a blown power supply that I can't seem to fix. I thought I had it fixed in 2010, but it died again in 2015: http://www.learnbydestroying.com/jeffl/IFR-1500%20Power%20Supply%20Repair/IFR-1500%20power%20supply%20repair.html Does that answer your question? Yes, thanks. I was curious about the counters as I have some post-design experience of some of the later models in that range, but yours were a bit before my time (mid-70s, IIRC). I might have been able to help you out with hard-to-get parts. |
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