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"Uwe" wrote in message ... I monitor the output signal on my scope and notice that right after key down the waveform contract just a bit and the tone changes pitch. I guess this is called chirp. I normally use B+ 200V. If I increase the voltage lets say to 300V this effect becomes much more pronounced. I still use an external bench supply capable of much higher currents and I don't think it is a power supply weakness. In fact putting a VOM on the supply line shows no sag in my supply voltage. I think 200 V is enough. Someone here probably knows what the AC-1 design voltage was, but I'm sure it wasn't 300 V, and may be have more like 150 V. While the 6V6 can handle higher voltages, as a keyed crystal oscillator, you don't want to overdo it. You could fracture a crystal, too. There's quite a bit of AC-1 lore online. Use http://www.google.com/search?q=ameco+ac-1 to find it. I even found a copy of the original AC-1 manual, but it doesn't show circuit voltages. Congrats on getting your ticket and making your first QSO. Now it's time to put this antique away and build some safe, cool, solid-state gear! 73, "PM" |
Congrats on getting your ticket and making your first QSO. Now it's time to put this antique away and build some safe, cool, solid-state gear! I disagree somewhat. There is a lot to be learned from simple gear, tube or otherwise. Tube gear is more forgiving of the mistakes we inevitably make while learning. It will also bite you if you are not careful, so you learn respect. He should try the classic 6CG7 807 transmitter next - a bit more power and a lot less chirp. It can be a lot of fun making contacts with this kind of simple equipment, and it improves your code proficiency to the point you might even decide code is fun. Doug Moore KB9TMY |
Congrats on getting your ticket and making your first QSO. Now it's time to put this antique away and build some safe, cool, solid-state gear! I disagree somewhat. There is a lot to be learned from simple gear, tube or otherwise. Tube gear is more forgiving of the mistakes we inevitably make while learning. It will also bite you if you are not careful, so you learn respect. He should try the classic 6CG7 807 transmitter next - a bit more power and a lot less chirp. It can be a lot of fun making contacts with this kind of simple equipment, and it improves your code proficiency to the point you might even decide code is fun. Doug Moore KB9TMY |
Uwe wrote:
With the help of some folks here I did troubleshoot my AC-1 tube transmitter (using a 6V6) and got it working somehow. Since I passed my code test and had my first QSO using the transmitter and boy was that exciting. But questions remain. I monitor the output signal on my scope and notice that right after key down the waveform contract just a bit and the tone changes pitch. I guess this is called chirp. I normally use B+ 200V. If I increase the voltage lets say to 300V this effect becomes much more pronounced. I still use an external bench supply capable of much higher currents and I don't think it is a power supply weakness. In fact putting a VOM on the supply line shows no sag in my supply voltage. How can I minimize this and especially keep it from becoming more severe at higher outputs. Also, the circuit diagram for the tranmitter did not state the coil diameter of the pi network. The pi network still has me scratching my head. Coils with slight variations in diameter give dramatically different results. Also changing the air cap with one of an identical range can have a vast effect, which surprised me. Is this the "real world components" versus the theory??? Uwe I don't have the schematic, but if the screen voltage comes from the usual dropping resistor & bypass cap then it is probably dropping a little bit under load. This will cause the plate current & output power to fall a bit, and change the operating characteristics enough to chirp a little bit. As mentioned by another poster, this is the nature of a single-tube transmitter (or single-anything power oscillator, for that matter). No matter what you do the amplifier characteristics will be different for different RF outputs, so the frequency _will_ change. You can minimize it but you can't make it go away. --------------------------------------- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
Uwe wrote:
With the help of some folks here I did troubleshoot my AC-1 tube transmitter (using a 6V6) and got it working somehow. Since I passed my code test and had my first QSO using the transmitter and boy was that exciting. But questions remain. I monitor the output signal on my scope and notice that right after key down the waveform contract just a bit and the tone changes pitch. I guess this is called chirp. I normally use B+ 200V. If I increase the voltage lets say to 300V this effect becomes much more pronounced. I still use an external bench supply capable of much higher currents and I don't think it is a power supply weakness. In fact putting a VOM on the supply line shows no sag in my supply voltage. How can I minimize this and especially keep it from becoming more severe at higher outputs. Also, the circuit diagram for the tranmitter did not state the coil diameter of the pi network. The pi network still has me scratching my head. Coils with slight variations in diameter give dramatically different results. Also changing the air cap with one of an identical range can have a vast effect, which surprised me. Is this the "real world components" versus the theory??? Uwe I don't have the schematic, but if the screen voltage comes from the usual dropping resistor & bypass cap then it is probably dropping a little bit under load. This will cause the plate current & output power to fall a bit, and change the operating characteristics enough to chirp a little bit. As mentioned by another poster, this is the nature of a single-tube transmitter (or single-anything power oscillator, for that matter). No matter what you do the amplifier characteristics will be different for different RF outputs, so the frequency _will_ change. You can minimize it but you can't make it go away. --------------------------------------- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
Uwe wrote in message ...
With the help of some folks here I did troubleshoot my AC-1 tube transmitter (using a 6V6) and got it working somehow. Since I passed my code test and had my first QSO using the transmitter and boy was that exciting. Congatulations and well done! But questions remain. I monitor the output signal on my scope and notice that right after key down the waveform contract just a bit and the tone changes pitch. I guess this is called chirp. That's correct. You won't see it much on a 'scope but you can hear it. I normally use B+ 200V. If I increase the voltage lets say to 300V this effect becomes much more pronounced. I still use an external bench supply capable of much higher currents and I don't think it is a power supply weakness. In fact putting a VOM on the supply line shows no sag in my supply voltage. How can I minimize this and especially keep it from becoming more severe at higher outputs. Several things to check: 1) If the receiver you are using to monitor the signal is overloaded by the strong local signal, it can make the signal sound like it is chirping or clicking even if no such chirps or clicks actually exist. This is particularly true if the receiver isn't really meant for CW use. What are you using to listen to the transmitter's signal? 2) Besides the power supply, chirp in that sort of rig can be caused by: a) the crystal - try a different one if you can b) the feedback capacitors (the one from the grid to cathode, and the one from cathode to ground). These control the feedback in the oscillator, and if there is too much or too little, chirp can result. c) the 6V6GT tube - try a different one if you can d) output tuning - maximum output is often not the best setting for chirp. Also, the circuit diagram for the tranmitter did not state the coil diameter of the pi network. It's 1-1/4 inches. The pi network still has me scratching my head. Coils with slight variations in diameter give dramatically different results. That's to be expected. A common formula for the inductance of a solenoidal air-core coil is: L = (a * a * n * n)/ ((9 * a) + (10 * b)) where L = inductance in uH a = radius of coil winding in inches b = length of coil winding in inches n = number of turns Also changing the air cap with one of an identical range can have a vast effect, which surprised me. Is this the "real world components" versus the theory??? Perhaps - but how do you know the caps are the same value? 73 es hope to CU on 40 Jim, N2EY Uwe |
Uwe wrote in message ...
With the help of some folks here I did troubleshoot my AC-1 tube transmitter (using a 6V6) and got it working somehow. Since I passed my code test and had my first QSO using the transmitter and boy was that exciting. Congatulations and well done! But questions remain. I monitor the output signal on my scope and notice that right after key down the waveform contract just a bit and the tone changes pitch. I guess this is called chirp. That's correct. You won't see it much on a 'scope but you can hear it. I normally use B+ 200V. If I increase the voltage lets say to 300V this effect becomes much more pronounced. I still use an external bench supply capable of much higher currents and I don't think it is a power supply weakness. In fact putting a VOM on the supply line shows no sag in my supply voltage. How can I minimize this and especially keep it from becoming more severe at higher outputs. Several things to check: 1) If the receiver you are using to monitor the signal is overloaded by the strong local signal, it can make the signal sound like it is chirping or clicking even if no such chirps or clicks actually exist. This is particularly true if the receiver isn't really meant for CW use. What are you using to listen to the transmitter's signal? 2) Besides the power supply, chirp in that sort of rig can be caused by: a) the crystal - try a different one if you can b) the feedback capacitors (the one from the grid to cathode, and the one from cathode to ground). These control the feedback in the oscillator, and if there is too much or too little, chirp can result. c) the 6V6GT tube - try a different one if you can d) output tuning - maximum output is often not the best setting for chirp. Also, the circuit diagram for the tranmitter did not state the coil diameter of the pi network. It's 1-1/4 inches. The pi network still has me scratching my head. Coils with slight variations in diameter give dramatically different results. That's to be expected. A common formula for the inductance of a solenoidal air-core coil is: L = (a * a * n * n)/ ((9 * a) + (10 * b)) where L = inductance in uH a = radius of coil winding in inches b = length of coil winding in inches n = number of turns Also changing the air cap with one of an identical range can have a vast effect, which surprised me. Is this the "real world components" versus the theory??? Perhaps - but how do you know the caps are the same value? 73 es hope to CU on 40 Jim, N2EY Uwe |
In article ,
"Paul_Morphy" writes: "Uwe" wrote in message ... I monitor the output signal on my scope and notice that right after key down the waveform contract just a bit and the tone changes pitch. I guess this is called chirp. I normally use B+ 200V. If I increase the voltage lets say to 300V this effect becomes much more pronounced. I still use an external bench supply capable of much higher currents and I don't think it is a power supply weakness. In fact putting a VOM on the supply line shows no sag in my supply voltage. I think 200 V is enough. Not really. The original design uses about 300-325 volts. Someone here probably knows what the AC-1 design voltage was, but I'm sure it wasn't 300 V, and may be have more like 150 V. Check the power transformer - it gave at least 300 volts with the 6X5 rectifier specified. The AC-1 was spec'd at 15 watts input, which means about 40 mA at 350 volts! While the 6V6 can handle higher voltages, as a keyed crystal oscillator, you don't want to overdo it. You could fracture a crystal, too. I ran a similar transmitter as a Novice. 350 volts on the plate of a 6V6GT, grid-plate circuit. Xtals were fine, both on 80 and 40 meters. Those were FT-243s, though. Smaller xtals need a bit more care. A 6AG7 is a lot easier on the xtal than a 6V6. There's quite a bit of AC-1 lore online. Use http://www.google.com/search?q=ameco+ac-1 to find it. I even found a copy of the original AC-1 manual, but it doesn't show circuit voltages. Congrats on getting your ticket and making your first QSO. YES! Now it's time to put this antique away and build some safe, cool, solid-state gear! Why? If it does the job, what's the problem? As another poster commented, the next step is a classic 6AG7/807 MOPA design (or similar tubes - lots of choices, like the 6BG6, 6DQ6, 1625, etc). With a few more parts than the AC-1, you can get 40-50 watts output. And learn a lot in the process. 73 de Jim, N2EY |
In article ,
"Paul_Morphy" writes: "Uwe" wrote in message ... I monitor the output signal on my scope and notice that right after key down the waveform contract just a bit and the tone changes pitch. I guess this is called chirp. I normally use B+ 200V. If I increase the voltage lets say to 300V this effect becomes much more pronounced. I still use an external bench supply capable of much higher currents and I don't think it is a power supply weakness. In fact putting a VOM on the supply line shows no sag in my supply voltage. I think 200 V is enough. Not really. The original design uses about 300-325 volts. Someone here probably knows what the AC-1 design voltage was, but I'm sure it wasn't 300 V, and may be have more like 150 V. Check the power transformer - it gave at least 300 volts with the 6X5 rectifier specified. The AC-1 was spec'd at 15 watts input, which means about 40 mA at 350 volts! While the 6V6 can handle higher voltages, as a keyed crystal oscillator, you don't want to overdo it. You could fracture a crystal, too. I ran a similar transmitter as a Novice. 350 volts on the plate of a 6V6GT, grid-plate circuit. Xtals were fine, both on 80 and 40 meters. Those were FT-243s, though. Smaller xtals need a bit more care. A 6AG7 is a lot easier on the xtal than a 6V6. There's quite a bit of AC-1 lore online. Use http://www.google.com/search?q=ameco+ac-1 to find it. I even found a copy of the original AC-1 manual, but it doesn't show circuit voltages. Congrats on getting your ticket and making your first QSO. YES! Now it's time to put this antique away and build some safe, cool, solid-state gear! Why? If it does the job, what's the problem? As another poster commented, the next step is a classic 6AG7/807 MOPA design (or similar tubes - lots of choices, like the 6BG6, 6DQ6, 1625, etc). With a few more parts than the AC-1, you can get 40-50 watts output. And learn a lot in the process. 73 de Jim, N2EY |
Uwe wrote in message ...
With the help of some folks here I did troubleshoot my AC-1 tube transmitter (using a 6V6) and got it working somehow. Since I passed my code test and had my first QSO using the transmitter and boy was that exciting. But questions remain. I monitor the output signal on my scope and notice that right after key down the waveform contract just a bit and the tone changes pitch. I guess this is called chirp. I normally use B+ 200V. If I increase the voltage lets say to 300V this effect becomes much more pronounced. I still use an external bench supply capable of much higher currents and I don't think it is a power supply weakness. In fact putting a VOM on the supply line shows no sag in my supply voltage. How can I minimize this and especially keep it from becoming more severe at higher outputs. Also, the circuit diagram for the tranmitter did not state the coil diameter of the pi network. The pi network still has me scratching my head. Coils with slight variations in diameter give dramatically different results. Also changing the air cap with one of an identical range can have a vast effect, which surprised me. Is this the "real world components" versus the theory??? Uwe ---------------- Congratulations! I still have my original Ameco AC-1 15-Watt CW transmitter, completely intact with all original parts and accessories, all in perfect like-new condition, and a copy of the whole manual. If you want me to look at or measure anything for you (e.g. the coil you mentioned?), just let me know. I am at tomg AT fullnet.com . By the way, I think that I paid $14.98 for the Ameco AC-1 kit, new, back in about 1969. I built it, tested it, and then never used it. And I HAVE had people offer me hundreds of dollars for it, "out of the blue", several times over the last few years. There's a picture of it on my webpage (see URL, below). Good luck! Regards, Tom Gootee http://www.fullnet.com/u/tomg ----------------------------- |
Uwe wrote in message ...
With the help of some folks here I did troubleshoot my AC-1 tube transmitter (using a 6V6) and got it working somehow. Since I passed my code test and had my first QSO using the transmitter and boy was that exciting. But questions remain. I monitor the output signal on my scope and notice that right after key down the waveform contract just a bit and the tone changes pitch. I guess this is called chirp. I normally use B+ 200V. If I increase the voltage lets say to 300V this effect becomes much more pronounced. I still use an external bench supply capable of much higher currents and I don't think it is a power supply weakness. In fact putting a VOM on the supply line shows no sag in my supply voltage. How can I minimize this and especially keep it from becoming more severe at higher outputs. Also, the circuit diagram for the tranmitter did not state the coil diameter of the pi network. The pi network still has me scratching my head. Coils with slight variations in diameter give dramatically different results. Also changing the air cap with one of an identical range can have a vast effect, which surprised me. Is this the "real world components" versus the theory??? Uwe ---------------- Congratulations! I still have my original Ameco AC-1 15-Watt CW transmitter, completely intact with all original parts and accessories, all in perfect like-new condition, and a copy of the whole manual. If you want me to look at or measure anything for you (e.g. the coil you mentioned?), just let me know. I am at tomg AT fullnet.com . By the way, I think that I paid $14.98 for the Ameco AC-1 kit, new, back in about 1969. I built it, tested it, and then never used it. And I HAVE had people offer me hundreds of dollars for it, "out of the blue", several times over the last few years. There's a picture of it on my webpage (see URL, below). Good luck! Regards, Tom Gootee http://www.fullnet.com/u/tomg ----------------------------- |
Only now do I have a chance to react to some of the suggestions... I guess one poster here is right, I will just have to fiddle a bit more with the pi network (since at the B+ voltages suggested here my plate current would be way high) and I will have to live with the chirp. Nobody has complained yet anyways and maybe the chirp is worse in my receiver than on the air, as someone here suggested. By the way I use a Icom R75 for a receiver and switch the antenna off during transmit-still plenty of a signal seems to get into the receiver anyways. By the way, I see suggestions how to just "stretch" crystal controlled oscillators a bit by adding a suitable coil and capacitor in series with the crystal. Has anybody tried that with the AC-1?? Would be nice to be able to get out of the ways of some of the big power guys. Any suggestion would be welcome. Uwe |
Only now do I have a chance to react to some of the suggestions... I guess one poster here is right, I will just have to fiddle a bit more with the pi network (since at the B+ voltages suggested here my plate current would be way high) and I will have to live with the chirp. Nobody has complained yet anyways and maybe the chirp is worse in my receiver than on the air, as someone here suggested. By the way I use a Icom R75 for a receiver and switch the antenna off during transmit-still plenty of a signal seems to get into the receiver anyways. By the way, I see suggestions how to just "stretch" crystal controlled oscillators a bit by adding a suitable coil and capacitor in series with the crystal. Has anybody tried that with the AC-1?? Would be nice to be able to get out of the ways of some of the big power guys. Any suggestion would be welcome. Uwe |
"Uwe" wrote in message ... By the way, I see suggestions how to just "stretch" crystal controlled oscillators a bit by adding a suitable coil and capacitor in series with the crystal. Has anybody tried that with the AC-1?? Would be nice to be able to get out of the ways of some of the big power guys. Any suggestion would be welcome. An rf choke or variable inductor of between 7 and 20 uH in series with a variable cap of about 200 pF in series with a crystal, will pull the frequency. It's called a variable crystal oscillator or VXO. You're probably using FT-243 crystals, though, and they don't pull very far. I have to say this again: Time to put this thing on the shelf. For the time and trouble you are putting into it you could build a solid-state rig that would put out as much power, have a VFO and not contain life-threatening voltages. 73, "PM" |
"Uwe" wrote in message ... By the way, I see suggestions how to just "stretch" crystal controlled oscillators a bit by adding a suitable coil and capacitor in series with the crystal. Has anybody tried that with the AC-1?? Would be nice to be able to get out of the ways of some of the big power guys. Any suggestion would be welcome. An rf choke or variable inductor of between 7 and 20 uH in series with a variable cap of about 200 pF in series with a crystal, will pull the frequency. It's called a variable crystal oscillator or VXO. You're probably using FT-243 crystals, though, and they don't pull very far. I have to say this again: Time to put this thing on the shelf. For the time and trouble you are putting into it you could build a solid-state rig that would put out as much power, have a VFO and not contain life-threatening voltages. 73, "PM" |
"Paul_Morphy" wrote in message ... " I have to say this again: Time to put this thing on the shelf. For the time and trouble you are putting into it you could build a solid-state rig that would put out as much power, have a VFO and not contain life-threatening voltages. 73, "PM" I suggest he put all his radios on a shelf, and get a cell phone. No dangerous RF levels, no deadly voltages... NOT |
"Paul_Morphy" wrote in message ... " I have to say this again: Time to put this thing on the shelf. For the time and trouble you are putting into it you could build a solid-state rig that would put out as much power, have a VFO and not contain life-threatening voltages. 73, "PM" I suggest he put all his radios on a shelf, and get a cell phone. No dangerous RF levels, no deadly voltages... NOT |
" Uncle Peter" wrote in message news:vQnbc.9210$pM1.6556@lakeread06... I suggest he put all his radios on a shelf, and get a cell phone. No dangerous RF levels, no deadly voltages... NOT Gee, Unc, have a tough week? : I don't want him to give up radio, I just don't think an Ameco AC-1 is worth the trouble. I didn't want one when I was 15 and they were new, and I wouldn't waste my time fiddling with one now. 73, "PM" |
" Uncle Peter" wrote in message news:vQnbc.9210$pM1.6556@lakeread06... I suggest he put all his radios on a shelf, and get a cell phone. No dangerous RF levels, no deadly voltages... NOT Gee, Unc, have a tough week? : I don't want him to give up radio, I just don't think an Ameco AC-1 is worth the trouble. I didn't want one when I was 15 and they were new, and I wouldn't waste my time fiddling with one now. 73, "PM" |
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"Uwe" wrote in message ... And Paul, lest you get the impression I hate silicon, I just finished a Rockmite-very cute. There may be hope for you after all, Uwe. : I went through a boatanchors-revisited phase about 10 years ago, when I finally got to own two Drake 2Bs, an Eico 720 with Hallicrafters HA-5 VFO and a Ranger II (thanks to the Hosstraders flea market in New Hampshire, which you shouldn't miss), my dream stations when I was 15. I never cared a lot for the voice modes, either; CW is my mode of choice. After lugging those relatively small boatanchors around a little, though, I decided to get back to the present. For inspiration along the silicon lines (and to see some really nice photos of mountains in the Pacific NW) I recommend Wes Hayward's (W7ZOI) site: http://users.easystreet.com/w7zoi/w7zoi-page.html 73, "PM" |
"Uwe" wrote in message ... And Paul, lest you get the impression I hate silicon, I just finished a Rockmite-very cute. There may be hope for you after all, Uwe. : I went through a boatanchors-revisited phase about 10 years ago, when I finally got to own two Drake 2Bs, an Eico 720 with Hallicrafters HA-5 VFO and a Ranger II (thanks to the Hosstraders flea market in New Hampshire, which you shouldn't miss), my dream stations when I was 15. I never cared a lot for the voice modes, either; CW is my mode of choice. After lugging those relatively small boatanchors around a little, though, I decided to get back to the present. For inspiration along the silicon lines (and to see some really nice photos of mountains in the Pacific NW) I recommend Wes Hayward's (W7ZOI) site: http://users.easystreet.com/w7zoi/w7zoi-page.html 73, "PM" |
in article ,
Paul_Morphy at wrote on 4/3/04 06:20: "Uwe" wrote in message ... And Paul, lest you get the impression I hate silicon, I just finished a Rockmite-very cute. There may be hope for you after all, Uwe. : I went through a boatanchors-revisited phase about 10 years ago, when I finally got to own two Drake 2Bs, an Eico 720 with Hallicrafters HA-5 VFO and a Ranger II (thanks to the Hosstraders flea market in New Hampshire, which you shouldn't miss), my dream stations when I was 15. I never cared a lot for the voice modes, either; CW is my mode of choice. After lugging those relatively small boatanchors around a little, though, I decided to get back to the present. For inspiration along the silicon lines (and to see some really nice photos of mountains in the Pacific NW) I recommend Wes Hayward's (W7ZOI) site: http://users.easystreet.com/w7zoi/w7zoi-page.html 73, "PM" Paul, how interesting, I just had Wes Haywards book in hand the other day at a local hamfest. I own the Solid State Design Book and had considered Radio Frequency Design but found that one rather technical. But "Experimental Methods in RF Design" caught my eye but also caught me at the end of the day without the necessary $50 to take it home. Experimenting is really what all this is about for me and I do lack some of the foundations and tools for successful RF tinkering, so I always look for a good introduction. And somehow tubes, which seem to deal with electrons on a macroscopic, nearly mechanical level seem to be a bit more accessible than transistors which I think deal with all this on an atomic level. And here you send me a link to Haywards website. Well thanks, and yes, nice mountains. I went and added a choke and a capacitor to my crystal and believe it or not it actually still oscillated. I did some measurements and found that I can pull the crystal (I used one of the crystals out of the rockmite!) from 7038 to 7040, after being rockbound that feels like now I am "all over the place". And while I was fiddeling with the radio I heard a station and ran my first QSO on a frequency I couldn't get to until 3 hours ago, with rigged up parts and clip leads all over the place!! Radio work at its finest. But one solution immediately leads to the next problem, how do I know where I am. What do they call them, frequency counters??? Regards Uwe |
"Uwe" wrote in message ... Paul, how interesting, I just had Wes Haywards book in hand the other day at a local hamfest. I own the Solid State Design Book and had considered Radio Frequency Design but found that one rather technical. But "Experimental Methods in RF Design" caught my eye but also caught me at the end of the day without the necessary $50 to take it home. Yes, I'm resisting spending the money, too. I can buy a lotta parts with 50 bucks. And somehow tubes, which seem to deal with electrons on a macroscopic, nearly mechanical level seem to be a bit more accessible than transistors which I think deal with all this on an atomic level. Electrons don't know where they are, tube or semiconductor, it's all the same to them. Study the intro chapters in the Handbook and SSD and do some experiments and it wil start to make sense. But one solution immediately leads to the next problem, how do I know where I am. What do they call them, frequency counters??? Uwe, if you don't know where you are, you are asking on the wrong newsgroup. : If you're only moving 2 kHz and you're well inside the band, it really doesn't matter. You have a digital display on your receiver, so you should be able to kluge something together that will let you zero beat the other station. Be careful with those little crystals. They won't take a lot of current, not as much as one in an FT-243 holder. You could pop it. You'll hear it click when it blows. Why not build a VFO from SSD? 73, "PM" |
"Uwe" wrote in message ... Paul, how interesting, I just had Wes Haywards book in hand the other day at a local hamfest. I own the Solid State Design Book and had considered Radio Frequency Design but found that one rather technical. But "Experimental Methods in RF Design" caught my eye but also caught me at the end of the day without the necessary $50 to take it home. Yes, I'm resisting spending the money, too. I can buy a lotta parts with 50 bucks. And somehow tubes, which seem to deal with electrons on a macroscopic, nearly mechanical level seem to be a bit more accessible than transistors which I think deal with all this on an atomic level. Electrons don't know where they are, tube or semiconductor, it's all the same to them. Study the intro chapters in the Handbook and SSD and do some experiments and it wil start to make sense. But one solution immediately leads to the next problem, how do I know where I am. What do they call them, frequency counters??? Uwe, if you don't know where you are, you are asking on the wrong newsgroup. : If you're only moving 2 kHz and you're well inside the band, it really doesn't matter. You have a digital display on your receiver, so you should be able to kluge something together that will let you zero beat the other station. Be careful with those little crystals. They won't take a lot of current, not as much as one in an FT-243 holder. You could pop it. You'll hear it click when it blows. Why not build a VFO from SSD? 73, "PM" |
Paul_Morphy wrote:
I have to say this again: Time to put this thing on the shelf. For the time and trouble you are putting into it you could build a solid-state rig that would put out as much power, have a VFO and not contain life-threatening voltages. 73, "PM" And don't go mountain climbing. And don't drive race cars. And don't learn how to do aerobatics. Etc. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
Paul_Morphy wrote:
I have to say this again: Time to put this thing on the shelf. For the time and trouble you are putting into it you could build a solid-state rig that would put out as much power, have a VFO and not contain life-threatening voltages. 73, "PM" And don't go mountain climbing. And don't drive race cars. And don't learn how to do aerobatics. Etc. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
"Tim Wescott" wrote in message ... And don't go mountain climbing. And don't drive race cars. And don't learn how to do aerobatics. Well, I've only done the first two. I was just trying to persuade him to take up solid-state stuff. He keeps talking about the HV power supply on his bench and that makes me think of how nice it is to work at 12 V. BTW, I found mountaineering and racing a helluva lot more exciting than working with vacuum tubes. 73, "PM" |
"Tim Wescott" wrote in message ... And don't go mountain climbing. And don't drive race cars. And don't learn how to do aerobatics. Well, I've only done the first two. I was just trying to persuade him to take up solid-state stuff. He keeps talking about the HV power supply on his bench and that makes me think of how nice it is to work at 12 V. BTW, I found mountaineering and racing a helluva lot more exciting than working with vacuum tubes. 73, "PM" |
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12V, holy cow! If I go low voltage I keep it at around 5. I am building a controller board with basic stamps and recently fried an A/D chip by letting it have 12V, it was lethal. By the way, talking about overload. The issue of crystals breaking has been mentioned a few times, but how do I measure what the crystal "sees" for current and what is tooo much??? 73 Uwe You can use a panel lamp in series with the crystal to limit the current (too much current causes the lamp to glow, increasing the resistance, limiting the current)... Check some of the earlier handbooks for the proper lamp to use... A 47 might be a good start. This is really a bigger problem when crystals other than the older pressure mount FT243 are used (modern plated lead connections) or with larger PA tubes used as oscillators (6L6, 807, etc.) Pete |
12V, holy cow! If I go low voltage I keep it at around 5. I am building a controller board with basic stamps and recently fried an A/D chip by letting it have 12V, it was lethal. By the way, talking about overload. The issue of crystals breaking has been mentioned a few times, but how do I measure what the crystal "sees" for current and what is tooo much??? 73 Uwe You can use a panel lamp in series with the crystal to limit the current (too much current causes the lamp to glow, increasing the resistance, limiting the current)... Check some of the earlier handbooks for the proper lamp to use... A 47 might be a good start. This is really a bigger problem when crystals other than the older pressure mount FT243 are used (modern plated lead connections) or with larger PA tubes used as oscillators (6L6, 807, etc.) Pete |
"Paul_Morphy" wrote in message ... " Uncle Peter" wrote in message news:vQnbc.9210$pM1.6556@lakeread06... I suggest he put all his radios on a shelf, and get a cell phone. No dangerous RF levels, no deadly voltages... NOT Gee, Unc, have a tough week? : I don't want him to give up radio, I just don't think an Ameco AC-1 is worth the trouble. I didn't want one when I was 15 and they were new, and I wouldn't waste my time fiddling with one now. 73, "PM" No, but you have some issues. The other guy is "having fun" with his Ameco, why don't you give it a rest? That isn't exactly the most dangerous boatanchor I can think off. Thank god you don't frequent the boatanchor group, you'd be flipping out. Pete |
"Paul_Morphy" wrote in message ... " Uncle Peter" wrote in message news:vQnbc.9210$pM1.6556@lakeread06... I suggest he put all his radios on a shelf, and get a cell phone. No dangerous RF levels, no deadly voltages... NOT Gee, Unc, have a tough week? : I don't want him to give up radio, I just don't think an Ameco AC-1 is worth the trouble. I didn't want one when I was 15 and they were new, and I wouldn't waste my time fiddling with one now. 73, "PM" No, but you have some issues. The other guy is "having fun" with his Ameco, why don't you give it a rest? That isn't exactly the most dangerous boatanchor I can think off. Thank god you don't frequent the boatanchor group, you'd be flipping out. Pete |
" Uncle Peter" wrote in message news:b0Xbc.10404$pM1.5246@lakeread06... No, but you have some issues. The other guy is "having fun" with his Ameco, why don't you give it a rest? That isn't exactly the most dangerous boatanchor I can think off. Thank god you don't frequent the boatanchor group, you'd be flipping out. What makes you think I don't? I've horsetraded quite a few BAs in my time, many of which stuck around for my own use. My point was, and is, for the time spent, there may be greater rewards from pursuing a different aspect of the hobby. Ie, he's stuck on mountain climbing, and he might enjoy racing, too. I find it fascinating that some people project my concerns about obvious newbies fooling with HV into a condemnation of trying something different, especially when 'trying something different' was my point from the outset. Uwe is certainly as free to accept or disregard my advice as I am to give it. 73, "PM" |
" Uncle Peter" wrote in message news:b0Xbc.10404$pM1.5246@lakeread06... No, but you have some issues. The other guy is "having fun" with his Ameco, why don't you give it a rest? That isn't exactly the most dangerous boatanchor I can think off. Thank god you don't frequent the boatanchor group, you'd be flipping out. What makes you think I don't? I've horsetraded quite a few BAs in my time, many of which stuck around for my own use. My point was, and is, for the time spent, there may be greater rewards from pursuing a different aspect of the hobby. Ie, he's stuck on mountain climbing, and he might enjoy racing, too. I find it fascinating that some people project my concerns about obvious newbies fooling with HV into a condemnation of trying something different, especially when 'trying something different' was my point from the outset. Uwe is certainly as free to accept or disregard my advice as I am to give it. 73, "PM" |
In article , Uwe
writes: 12V, holy cow! If I go low voltage I keep it at around 5. I am building a controller board with basic stamps and recently fried an A/D chip by letting it have 12V, it was lethal. Heh heh heh...you low-voltage kids are all alike. Us vacuum veterans would not think twice about the +120 VDC (the "B+") in the old "All-American Five" cheap table model AM BC radios.... :-) By the way, talking about overload. The issue of crystals breaking has been mentioned a few times, but how do I measure what the crystal "sees" for current and what is tooo much??? Seriously, folks, the websites for International Crystal, Corning Frequency Control division, etc., all give specs on various sizes and cuts of their quartz crystal units. Few really "measure" the crystal drive levels since that can be done analytically...if one knows how to do this. If not, there are several hints on the various crystal unit websites for approximating that, such as typical circuits. The best approach at the beginning is to take advice from others on what works and what doesn't...such as the old, old FT-243 holder crystals can take more power dissipation (thicker slice of quartz) than most of the smaller HC-6 holder units. The newer SMD quartz crystal units have very low power specs and should not be used with most vacuum tube circuits because of that. Having been in the electron-pushing racket for better than a half century and bridging the tube and transistor eras, I've never experienced any quartz crystal physically "breaking." If a quartz crystal circuit stopped working, the quartz unit just sat there without a sound, same as it did when it worked OK. :-) Only the oscilloscope trace knew what was in the hearts of such circuits... Len Anderson retired (from regular hours) electronic engineer person |
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