Home |
Search |
Today's Posts |
#81
![]() |
|||
|
|||
![]()
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 |
#82
![]() |
|||
|
|||
![]()
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. |
#83
![]() |
|||
|
|||
![]()
On Mon, 15 Oct 2018, Jim GM4DHJ ... wrote:
"Gareth's Downstairs Computer" wrote in message news ![]() 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 |
#84
![]() |
|||
|
|||
![]()
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 |
#85
![]() |
|||
|
|||
![]()
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 |
#86
![]() |
|||
|
|||
![]() "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 news ![]() 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..... |
#87
![]() |
|||
|
|||
![]()
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" |
#88
![]() |
|||
|
|||
![]()
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 |
#89
![]() |
|||
|
|||
![]()
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" |
#90
![]() |
|||
|
|||
![]()
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" |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
a little 4nec2 help? | Antenna | |||
Anybody tried 4nec2 on Vista ? | Antenna | |||
New 4nec2 version | Antenna | |||
4nec2 and linux ?? | Antenna | |||
4nec2 question | Antenna |