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Have you seen this oscillator?
Hi, I'm trying to track down the name for a certain type of oscillator which I dimly recall seeing in an old book called Radio & Line Transmission that I bought and lost over 3 decades ago. In simple terms, it has a crystal in the base/emitter circuit and a C/L tank for the resonant frequency of the crystal in the collector circuit. In this way it can't flip into an overtone since it only has gain at the crystal's fundamental. Anyone know the name for it? Thanks, p. -- The BBC: Licensed at public expense to spread lies. |
"Paul Burridge" wrote in message ... Hi, I'm trying to track down the name for a certain type of oscillator which I dimly recall seeing in an old book called Radio & Line Transmission that I bought and lost over 3 decades ago. In simple terms, it has a crystal in the base/emitter circuit and a C/L tank for the resonant frequency of the crystal in the collector circuit. In this way it can't flip into an overtone since it only has gain at the crystal's fundamental. Anyone know the name for it? Why don't you think the crystal goes low impedance at it's odd harmonics? If you'll design the circuit properly, it will give no trouble with overtone operation. Don't remember ever having any problems selecting one to operate on the fundamental, usually, it's selecting between 5th and 7th overtone or 7th and 9th that gets a little sticky. W4ZCB |
"Paul Burridge" wrote in message ... Hi, I'm trying to track down the name for a certain type of oscillator which I dimly recall seeing in an old book called Radio & Line Transmission that I bought and lost over 3 decades ago. In simple terms, it has a crystal in the base/emitter circuit and a C/L tank for the resonant frequency of the crystal in the collector circuit. In this way it can't flip into an overtone since it only has gain at the crystal's fundamental. Anyone know the name for it? Why don't you think the crystal goes low impedance at it's odd harmonics? If you'll design the circuit properly, it will give no trouble with overtone operation. Don't remember ever having any problems selecting one to operate on the fundamental, usually, it's selecting between 5th and 7th overtone or 7th and 9th that gets a little sticky. W4ZCB |
In article lXI_b.395225$na.763604@attbi_s04, Harold E. Johnson
writes "Paul Burridge" wrote in message .. . Hi, I'm trying to track down the name for a certain type of oscillator which I dimly recall seeing in an old book called Radio & Line Transmission that I bought and lost over 3 decades ago. In simple terms, it has a crystal in the base/emitter circuit and a C/L tank for the resonant frequency of the crystal in the collector circuit. In this way it can't flip into an overtone since it only has gain at the crystal's fundamental. Anyone know the name for it? Why don't you think the crystal goes low impedance at it's odd harmonics? If you'll design the circuit properly, it will give no trouble with overtone operation. Don't remember ever having any problems selecting one to operate on the fundamental, usually, it's selecting between 5th and 7th overtone or 7th and 9th that gets a little sticky. W4ZCB A universal series resonant circuit "Butler?" meets most of your criteria. I dont like these names myself. Collector to +ve supply via tank LC with the C = 2 C in series the base decoupled to ground with a potential divider to set base bias and a low value (220R?) in the emitter to ground. The crystal goes from the junction of the 2 tapped capacitors and the emitter. The 2 Cs are arranged to lower the o/p impedance from the collector tank i.e. the C nearest the collector would be 100pF and the C to the +ve supply 330pF. With the LC arranged to resonate at the crystal frequency. The beauty of the circuit is that the crystal can be replaced by a 50R resistor and the circuit L and C tweaked to oscillate at the crystal freq. Can be used to select overtone or fundamental. -- ddwyer |
In article lXI_b.395225$na.763604@attbi_s04, Harold E. Johnson
writes "Paul Burridge" wrote in message .. . Hi, I'm trying to track down the name for a certain type of oscillator which I dimly recall seeing in an old book called Radio & Line Transmission that I bought and lost over 3 decades ago. In simple terms, it has a crystal in the base/emitter circuit and a C/L tank for the resonant frequency of the crystal in the collector circuit. In this way it can't flip into an overtone since it only has gain at the crystal's fundamental. Anyone know the name for it? Why don't you think the crystal goes low impedance at it's odd harmonics? If you'll design the circuit properly, it will give no trouble with overtone operation. Don't remember ever having any problems selecting one to operate on the fundamental, usually, it's selecting between 5th and 7th overtone or 7th and 9th that gets a little sticky. W4ZCB A universal series resonant circuit "Butler?" meets most of your criteria. I dont like these names myself. Collector to +ve supply via tank LC with the C = 2 C in series the base decoupled to ground with a potential divider to set base bias and a low value (220R?) in the emitter to ground. The crystal goes from the junction of the 2 tapped capacitors and the emitter. The 2 Cs are arranged to lower the o/p impedance from the collector tank i.e. the C nearest the collector would be 100pF and the C to the +ve supply 330pF. With the LC arranged to resonate at the crystal frequency. The beauty of the circuit is that the crystal can be replaced by a 50R resistor and the circuit L and C tweaked to oscillate at the crystal freq. Can be used to select overtone or fundamental. -- ddwyer |
You're probably thinking of the oscillator that Marv Frerking
called a "grounded-base oscillator". I have seen it called other names as well. Basically, what you do is first build an LC (ie no xtal) Colpitts oscillator and tune it to the crystal frequency you want to eventually use. Then insert a resistor of a few dozen ohms in series with the emitter. Now, readjust the feedback capacitors on the oscillator to get it to oscillate OK with the resistor. Finally, replace the resistor with a series resonant crystal. It will be forced to oscillate at the frequency of the original LC oscillator, since there is no gain anywhere else. Thus you can design for either the fundamental or a specific harmonic and like you say it can't flip to a different overtone. For more details, read one of Frerking's books. Rick N6RK "Paul Burridge" wrote in message ... Hi, I'm trying to track down the name for a certain type of oscillator which I dimly recall seeing in an old book called Radio & Line Transmission that I bought and lost over 3 decades ago. In simple terms, it has a crystal in the base/emitter circuit and a C/L tank for the resonant frequency of the crystal in the collector circuit. In this way it can't flip into an overtone since it only has gain at the crystal's fundamental. Anyone know the name for it? Thanks, p. -- The BBC: Licensed at public expense to spread lies. |
You're probably thinking of the oscillator that Marv Frerking
called a "grounded-base oscillator". I have seen it called other names as well. Basically, what you do is first build an LC (ie no xtal) Colpitts oscillator and tune it to the crystal frequency you want to eventually use. Then insert a resistor of a few dozen ohms in series with the emitter. Now, readjust the feedback capacitors on the oscillator to get it to oscillate OK with the resistor. Finally, replace the resistor with a series resonant crystal. It will be forced to oscillate at the frequency of the original LC oscillator, since there is no gain anywhere else. Thus you can design for either the fundamental or a specific harmonic and like you say it can't flip to a different overtone. For more details, read one of Frerking's books. Rick N6RK "Paul Burridge" wrote in message ... Hi, I'm trying to track down the name for a certain type of oscillator which I dimly recall seeing in an old book called Radio & Line Transmission that I bought and lost over 3 decades ago. In simple terms, it has a crystal in the base/emitter circuit and a C/L tank for the resonant frequency of the crystal in the collector circuit. In this way it can't flip into an overtone since it only has gain at the crystal's fundamental. Anyone know the name for it? Thanks, p. -- The BBC: Licensed at public expense to spread lies. |
You're probably thinking of the oscillator that Marv Frerking called a "grounded-base oscillator". Alternatively, take a look at the Butler design by John Stephensen in November/December 1999 QEX. He explains clearly why folks ever had problems with Butlers and better yet, how to cure them. I've used this circuit (without the Varactor tuning) on 9th overtone oscillators using hound dog crystals. W4ZCB |
You're probably thinking of the oscillator that Marv Frerking called a "grounded-base oscillator". Alternatively, take a look at the Butler design by John Stephensen in November/December 1999 QEX. He explains clearly why folks ever had problems with Butlers and better yet, how to cure them. I've used this circuit (without the Varactor tuning) on 9th overtone oscillators using hound dog crystals. W4ZCB |
On Tue, 24 Feb 2004 16:02:23 GMT, the renowned "Harold E. Johnson"
wrote: You're probably thinking of the oscillator that Marv Frerking called a "grounded-base oscillator". Alternatively, take a look at the Butler design by John Stephensen in November/December 1999 QEX. He explains clearly why folks ever had problems with Butlers and better yet, how to cure them. I've used this circuit (without the Varactor tuning) on 9th overtone oscillators using hound dog crystals. W4ZCB What's a "hound dog crystal"? How to deal with butlers: http://etext.library.adelaide.edu.au...chapter41.html Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
On Tue, 24 Feb 2004 16:02:23 GMT, the renowned "Harold E. Johnson"
wrote: You're probably thinking of the oscillator that Marv Frerking called a "grounded-base oscillator". Alternatively, take a look at the Butler design by John Stephensen in November/December 1999 QEX. He explains clearly why folks ever had problems with Butlers and better yet, how to cure them. I've used this circuit (without the Varactor tuning) on 9th overtone oscillators using hound dog crystals. W4ZCB What's a "hound dog crystal"? How to deal with butlers: http://etext.library.adelaide.edu.au...chapter41.html Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
What's a "hound dog crystal"? How to deal with butlers: http://etext.library.adelaide.edu.au...chapter41.html Best regards, Spehro Pefhany Thanks Spehro. Delightful! I wondered what it had to do with things until down the page a bit. Sorry for the lack of definition, I was referring to crystals not specifically treated to enhance overtone operation. When a manufacturer makes a crystal for overtone use, he/she treats it to suppress spurious responses close by the desired overtone so the crystal "likes" to operate properly. An untreated crystal often will have those responses and oscillate on one or more of them instead of the desired frequency unless the feedback and tuned circuit are carefully managed to ignore them. The higher impedance of Stephensens schematic make that a bit easier to do. Regards W4ZCB |
What's a "hound dog crystal"? How to deal with butlers: http://etext.library.adelaide.edu.au...chapter41.html Best regards, Spehro Pefhany Thanks Spehro. Delightful! I wondered what it had to do with things until down the page a bit. Sorry for the lack of definition, I was referring to crystals not specifically treated to enhance overtone operation. When a manufacturer makes a crystal for overtone use, he/she treats it to suppress spurious responses close by the desired overtone so the crystal "likes" to operate properly. An untreated crystal often will have those responses and oscillate on one or more of them instead of the desired frequency unless the feedback and tuned circuit are carefully managed to ignore them. The higher impedance of Stephensens schematic make that a bit easier to do. Regards W4ZCB |
On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK"
wrote: You're probably thinking of the oscillator that Marv Frerking called a "grounded-base oscillator". I have seen it called other names as well. Basically, what you do is first build an LC (ie no xtal) Colpitts oscillator and tune it to the crystal frequency you want to eventually use. [snip] Sounds like an oscillator that I've used since the '60's for my G-jobs (you know, the ones that *have* to work, 'cause they're for me :). See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website. I've never been able to get any custom IC customers to use it, since it takes three pins, but it works, period, no messy matching issues, even handles overtone modes. ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK"
wrote: You're probably thinking of the oscillator that Marv Frerking called a "grounded-base oscillator". I have seen it called other names as well. Basically, what you do is first build an LC (ie no xtal) Colpitts oscillator and tune it to the crystal frequency you want to eventually use. [snip] Sounds like an oscillator that I've used since the '60's for my G-jobs (you know, the ones that *have* to work, 'cause they're for me :). See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website. I've never been able to get any custom IC customers to use it, since it takes three pins, but it works, period, no messy matching issues, even handles overtone modes. ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
On Tue, 24 Feb 2004 12:26:22 -0700, Jim Thompson
wrote: On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK" wrote: You're probably thinking of the oscillator that Marv Frerking called a "grounded-base oscillator". I have seen it called other names as well. Basically, what you do is first build an LC (ie no xtal) Colpitts oscillator and tune it to the crystal frequency you want to eventually use. [snip] Sounds like an oscillator that I've used since the '60's for my G-jobs (you know, the ones that *have* to work, 'cause they're for me :). See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website. I've never been able to get any custom IC customers to use it, since it takes three pins, but it works, period, no messy matching issues, even handles overtone modes. ...Jim Thompson Aha! I just noted from Paul's post that "my" oscillator is called a two-transistor Butler. Wonder when that was conceived? I've been using the my direct-coupled version for 40 years. ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
On Tue, 24 Feb 2004 12:26:22 -0700, Jim Thompson
wrote: On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK" wrote: You're probably thinking of the oscillator that Marv Frerking called a "grounded-base oscillator". I have seen it called other names as well. Basically, what you do is first build an LC (ie no xtal) Colpitts oscillator and tune it to the crystal frequency you want to eventually use. [snip] Sounds like an oscillator that I've used since the '60's for my G-jobs (you know, the ones that *have* to work, 'cause they're for me :). See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website. I've never been able to get any custom IC customers to use it, since it takes three pins, but it works, period, no messy matching issues, even handles overtone modes. ...Jim Thompson Aha! I just noted from Paul's post that "my" oscillator is called a two-transistor Butler. Wonder when that was conceived? I've been using the my direct-coupled version for 40 years. ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |
On Tue, 24 Feb 2004 17:45:51 GMT, "Harold E. Johnson"
wrote: Sorry for the lack of definition, I was referring to crystals not specifically treated to enhance overtone operation. When a manufacturer makes a crystal for overtone use, he/she treats it to suppress spurious responses close by the desired overtone so the crystal "likes" to operate properly. An untreated crystal often will have those responses and oscillate on one or more of them instead of the desired frequency unless the feedback and tuned circuit are carefully managed to ignore them. The following link is worth checking out as an overview.... http://www.icmfg.com/crystaloscillatordata.html -- The BBC: Licensed at public expense to spread lies. |
On Tue, 24 Feb 2004 17:45:51 GMT, "Harold E. Johnson"
wrote: Sorry for the lack of definition, I was referring to crystals not specifically treated to enhance overtone operation. When a manufacturer makes a crystal for overtone use, he/she treats it to suppress spurious responses close by the desired overtone so the crystal "likes" to operate properly. An untreated crystal often will have those responses and oscillate on one or more of them instead of the desired frequency unless the feedback and tuned circuit are carefully managed to ignore them. The following link is worth checking out as an overview.... http://www.icmfg.com/crystaloscillatordata.html -- The BBC: Licensed at public expense to spread lies. |
Jim Thompson wrote:
On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK" wrote: You're probably thinking of the oscillator that Marv Frerking called a "grounded-base oscillator". I have seen it called other names as well. Basically, what you do is first build an LC (ie no xtal) Colpitts oscillator and tune it to the crystal frequency you want to eventually use. [snip] Sounds like an oscillator that I've used since the '60's for my G-jobs (you know, the ones that *have* to work, 'cause they're for me :). See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website. I've never been able to get any custom IC customers to use it, since it takes three pins, but it works, period, no messy matching issues, even handles overtone modes. ...Jim Thompson This pdf schematic looks very similar, except for the crystal and emitter part, to a circuit described in "Experimental Methods in RF Design" (p4.13). The circuit is described as "worth building......to observe first hand just what a noisy oscillator will sound like in a receiver". Earlier in the same chapter it appears in figure 4.13 as a type of negative resistance one port oscillator. I can only assume that the changes and crystal (in the circuit shown in the pdf) solve the problem of the "noisy" LC only configuration. I mention it as I built it up last night and took it into work today in order to have a look at the output on a spectrum analyser. Output was quite low at -27dBm. Sadly the HP kit couldn't measure phase noise directly, and I didn't have a good crystal oscillator to check it against. We were uncertain regarding the configuration too, but my colleague worked out that it had severe voltage limiting features and predicted the output swing quite accurately before it was measured on a scope. Last night I tried it with a number of inductors from the junk box and it oscillated quite readily from 114MHz down to 5MHz. I quite like the use of a non tapped L and only a single C. Shame about the phase noise :-(. regards... --Gary |
Jim Thompson wrote:
On Tue, 24 Feb 2004 15:29:43 GMT, "Rick Karlquist N6RK" wrote: You're probably thinking of the oscillator that Marv Frerking called a "grounded-base oscillator". I have seen it called other names as well. Basically, what you do is first build an LC (ie no xtal) Colpitts oscillator and tune it to the crystal frequency you want to eventually use. [snip] Sounds like an oscillator that I've used since the '60's for my G-jobs (you know, the ones that *have* to work, 'cause they're for me :). See "XtalSeriesOsc.pdf" on the S.E.D/Schematics page of my website. I've never been able to get any custom IC customers to use it, since it takes three pins, but it works, period, no messy matching issues, even handles overtone modes. ...Jim Thompson This pdf schematic looks very similar, except for the crystal and emitter part, to a circuit described in "Experimental Methods in RF Design" (p4.13). The circuit is described as "worth building......to observe first hand just what a noisy oscillator will sound like in a receiver". Earlier in the same chapter it appears in figure 4.13 as a type of negative resistance one port oscillator. I can only assume that the changes and crystal (in the circuit shown in the pdf) solve the problem of the "noisy" LC only configuration. I mention it as I built it up last night and took it into work today in order to have a look at the output on a spectrum analyser. Output was quite low at -27dBm. Sadly the HP kit couldn't measure phase noise directly, and I didn't have a good crystal oscillator to check it against. We were uncertain regarding the configuration too, but my colleague worked out that it had severe voltage limiting features and predicted the output swing quite accurately before it was measured on a scope. Last night I tried it with a number of inductors from the junk box and it oscillated quite readily from 114MHz down to 5MHz. I quite like the use of a non tapped L and only a single C. Shame about the phase noise :-(. regards... --Gary |
In article j5M_b.5335$AL.133044@attbi_s03, Harold E. Johnson
writes What's a "hound dog crystal"? How to deal with butlers: http://etext.library.adelaide.edu.au...chapter41.html Best regards, Spehro Pefhany Thanks Spehro. Delightful! I wondered what it had to do with things until down the page a bit. Sorry for the lack of definition, I was referring to crystals not specifically treated to enhance overtone operation. When a manufacturer makes a crystal for overtone use, he/she treats it to suppress spurious responses close by the desired overtone so the crystal "likes" to operate properly. An untreated crystal often will have those responses and oscillate on one or more of them instead of the desired frequency unless the feedback and tuned circuit are carefully managed to ignore them. The higher impedance of Stephensens schematic make that a bit easier to do. The special techniques were as follows: Optimise the plating thickness for the overtone and also the electrode diameter. Shear mode crystals have a controlled relationship between the resonant frequency under the electrode and the frequency away from the electroded region. Also higher overtones are better polished and more sensitive to parallelism. Overtones pull less approx pulling of fundimental/overtone number squared. -- ddwyer |
In article j5M_b.5335$AL.133044@attbi_s03, Harold E. Johnson
writes What's a "hound dog crystal"? How to deal with butlers: http://etext.library.adelaide.edu.au...chapter41.html Best regards, Spehro Pefhany Thanks Spehro. Delightful! I wondered what it had to do with things until down the page a bit. Sorry for the lack of definition, I was referring to crystals not specifically treated to enhance overtone operation. When a manufacturer makes a crystal for overtone use, he/she treats it to suppress spurious responses close by the desired overtone so the crystal "likes" to operate properly. An untreated crystal often will have those responses and oscillate on one or more of them instead of the desired frequency unless the feedback and tuned circuit are carefully managed to ignore them. The higher impedance of Stephensens schematic make that a bit easier to do. The special techniques were as follows: Optimise the plating thickness for the overtone and also the electrode diameter. Shear mode crystals have a controlled relationship between the resonant frequency under the electrode and the frequency away from the electroded region. Also higher overtones are better polished and more sensitive to parallelism. Overtones pull less approx pulling of fundimental/overtone number squared. -- ddwyer |
Found a source for 7360 and it is some interest among my friends for
using this tube in HF receivers, particularly for 80 and 40m It was mentioned an article by W2PUL(?) in QST using a high current twin triode as RF amplifier. Have seen the SSR-1 rx schematics. Is some more notes available on some sites for a modern version of receiver using these devices? I suspect some parts of the receiver could be improved over the practice used in the 60's Any suggestions? 73 ---- Jan-Martin, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/ |
Found a source for 7360 and it is some interest among my friends for
using this tube in HF receivers, particularly for 80 and 40m It was mentioned an article by W2PUL(?) in QST using a high current twin triode as RF amplifier. Have seen the SSR-1 rx schematics. Is some more notes available on some sites for a modern version of receiver using these devices? I suspect some parts of the receiver could be improved over the practice used in the 60's Any suggestions? 73 ---- Jan-Martin, LA8AK, N-4623 Kristiansand http://home.online.no/~la8ak/ |
"ddwyer" wrote in message ... In article j5M_b.5335$AL.133044@attbi_s03, Harold E. Johnson writes Hi Doug. I'm having mail bounce again going to you, new address, thought you might want to know. Looks like maybe, the newsgroup is the most reliable way to communicate! Regards W4ZCB |
"ddwyer" wrote in message ... In article j5M_b.5335$AL.133044@attbi_s03, Harold E. Johnson writes Hi Doug. I'm having mail bounce again going to you, new address, thought you might want to know. Looks like maybe, the newsgroup is the most reliable way to communicate! Regards W4ZCB |
"Jan-Martin Noeding, LA8AK" ) writes:
Found a source for 7360 and it is some interest among my friends for using this tube in HF receivers, particularly for 80 and 40m It was mentioned an article by W2PUL(?) in QST using a high current twin triode as RF amplifier. Have seen the SSR-1 rx schematics. Is some more notes available on some sites for a modern version of receiver using these devices? I suspect some parts of the receiver could be improved over the practice used in the 60's Any suggestions? The latest article I can think of seeing in print was February 1972. I may have the date wrong. It was by one of the QST staff members but not Doug DeMaw; I want to say Doug Blakeslee. It was a 3.5MHz receiver with a 455KHz design, hardly cutting edge. But it was intended for strong signal handling, so he used a tube in the RF stage that had higher current handling. He half jokingly suggested using an 807 in that stage. A lot of those articles using the 7360 used no RF stage, which is why you often saw a signal frequency Q-multiplier, to aid in image recection. Of course, by the time the 7360 was put to use, HF range IF filters were available so many of the receivers used an IF in the 5 or 9MHz range. Ray Moore had some articles in Ham Radio in 1972 and 1973 about receiver design, and the introductory piece covered mixers including the 7360, and then he had a "construction" article on a fancy AM BCB receiver, that used a 7360. Maybe some work was done with the mixer after that, but it pretty much faded from view from that point on. Michael VE2BVW |
"Jan-Martin Noeding, LA8AK" ) writes:
Found a source for 7360 and it is some interest among my friends for using this tube in HF receivers, particularly for 80 and 40m It was mentioned an article by W2PUL(?) in QST using a high current twin triode as RF amplifier. Have seen the SSR-1 rx schematics. Is some more notes available on some sites for a modern version of receiver using these devices? I suspect some parts of the receiver could be improved over the practice used in the 60's Any suggestions? The latest article I can think of seeing in print was February 1972. I may have the date wrong. It was by one of the QST staff members but not Doug DeMaw; I want to say Doug Blakeslee. It was a 3.5MHz receiver with a 455KHz design, hardly cutting edge. But it was intended for strong signal handling, so he used a tube in the RF stage that had higher current handling. He half jokingly suggested using an 807 in that stage. A lot of those articles using the 7360 used no RF stage, which is why you often saw a signal frequency Q-multiplier, to aid in image recection. Of course, by the time the 7360 was put to use, HF range IF filters were available so many of the receivers used an IF in the 5 or 9MHz range. Ray Moore had some articles in Ham Radio in 1972 and 1973 about receiver design, and the introductory piece covered mixers including the 7360, and then he had a "construction" article on a fancy AM BCB receiver, that used a 7360. Maybe some work was done with the mixer after that, but it pretty much faded from view from that point on. Michael VE2BVW |
"Michael Black" wrote in message ... "Jan-Martin Noeding, LA8AK" ) writes: Found a source for 7360 and it is some interest among my friends for using this tube in HF receivers, particularly for 80 and 40m It was mentioned an article by W2PUL(?) in QST using a high current twin triode as RF amplifier. Have seen the SSR-1 rx schematics. Is some more notes available on some sites for a modern version of receiver using these devices? I suspect some parts of the receiver could be improved over the practice used in the 60's Any suggestions? A couple, With Colin Horrabin's "H" mode mixer and the later switch mode mixers available for well under a buck, the mixer has been removed from being the concern it once was in receiver design. Since that topology, and the 4066/312X/500X solid state mixers yield better linearity than the following filters do, why return to the 7360? It was a fine mixer in it's day. That day is LONG past. Try operating a 7360 in any close proximity to a flourescent ballast. It will quickly disallusion you as to it's relative worth except as a curiosity. Vacuum tube receiver technology and modern is an oxymoron. W4ZCB |
"Michael Black" wrote in message ... "Jan-Martin Noeding, LA8AK" ) writes: Found a source for 7360 and it is some interest among my friends for using this tube in HF receivers, particularly for 80 and 40m It was mentioned an article by W2PUL(?) in QST using a high current twin triode as RF amplifier. Have seen the SSR-1 rx schematics. Is some more notes available on some sites for a modern version of receiver using these devices? I suspect some parts of the receiver could be improved over the practice used in the 60's Any suggestions? A couple, With Colin Horrabin's "H" mode mixer and the later switch mode mixers available for well under a buck, the mixer has been removed from being the concern it once was in receiver design. Since that topology, and the 4066/312X/500X solid state mixers yield better linearity than the following filters do, why return to the 7360? It was a fine mixer in it's day. That day is LONG past. Try operating a 7360 in any close proximity to a flourescent ballast. It will quickly disallusion you as to it's relative worth except as a curiosity. Vacuum tube receiver technology and modern is an oxymoron. W4ZCB |
On Tue, 24 Feb 2004 12:30:12 -0700, Jim Thompson
wrote: Aha! I just noted from Paul's post that "my" oscillator is called a two-transistor Butler. Wonder when that was conceived? I've been using the my direct-coupled version for 40 years. Interesting. This is the type I've decided to build as the basis for my next sweep generator attempt, since it's claimed the config is more amenable to being pulled than most others (although I won't be attempting to pull it anything like as much as my first abortive attempt using a Cmos-based inverter). Do you find it's a reliable and stable design, Jim? I assume if it wasn't you wouldn't still be using it! -- The BBC: Licensed at public expense to spread lies. |
On Tue, 24 Feb 2004 12:30:12 -0700, Jim Thompson
wrote: Aha! I just noted from Paul's post that "my" oscillator is called a two-transistor Butler. Wonder when that was conceived? I've been using the my direct-coupled version for 40 years. Interesting. This is the type I've decided to build as the basis for my next sweep generator attempt, since it's claimed the config is more amenable to being pulled than most others (although I won't be attempting to pull it anything like as much as my first abortive attempt using a Cmos-based inverter). Do you find it's a reliable and stable design, Jim? I assume if it wasn't you wouldn't still be using it! -- The BBC: Licensed at public expense to spread lies. |
Paul,
I think you started off speaking about crystal oscillators, but you just mentioned a sweep generator. Can you tell us a little more about your application?? Joe W3JDR "Paul Burridge" wrote in message ... On Tue, 24 Feb 2004 12:30:12 -0700, Jim Thompson wrote: Aha! I just noted from Paul's post that "my" oscillator is called a two-transistor Butler. Wonder when that was conceived? I've been using the my direct-coupled version for 40 years. Interesting. This is the type I've decided to build as the basis for my next sweep generator attempt, since it's claimed the config is more amenable to being pulled than most others (although I won't be attempting to pull it anything like as much as my first abortive attempt using a Cmos-based inverter). Do you find it's a reliable and stable design, Jim? I assume if it wasn't you wouldn't still be using it! -- The BBC: Licensed at public expense to spread lies. |
Paul,
I think you started off speaking about crystal oscillators, but you just mentioned a sweep generator. Can you tell us a little more about your application?? Joe W3JDR "Paul Burridge" wrote in message ... On Tue, 24 Feb 2004 12:30:12 -0700, Jim Thompson wrote: Aha! I just noted from Paul's post that "my" oscillator is called a two-transistor Butler. Wonder when that was conceived? I've been using the my direct-coupled version for 40 years. Interesting. This is the type I've decided to build as the basis for my next sweep generator attempt, since it's claimed the config is more amenable to being pulled than most others (although I won't be attempting to pull it anything like as much as my first abortive attempt using a Cmos-based inverter). Do you find it's a reliable and stable design, Jim? I assume if it wasn't you wouldn't still be using it! -- The BBC: Licensed at public expense to spread lies. |
On Wed, 25 Feb 2004 12:39:46 GMT, "W3JDR" wrote:
Paul, I think you started off speaking about crystal oscillators, but you just mentioned a sweep generator. Can you tell us a little more about your application?? Certainly. I've just finished roughing out the block diagram, actually and will try to post it later for some constructive criticism. It's basically just to sweep a half-meg segment in the 40Mhz band for the purpose of testing filters to improve rx selectivity in R/C applications.. -- The BBC: Licensed at public expense to spread lies. |
On Wed, 25 Feb 2004 12:39:46 GMT, "W3JDR" wrote:
Paul, I think you started off speaking about crystal oscillators, but you just mentioned a sweep generator. Can you tell us a little more about your application?? Certainly. I've just finished roughing out the block diagram, actually and will try to post it later for some constructive criticism. It's basically just to sweep a half-meg segment in the 40Mhz band for the purpose of testing filters to improve rx selectivity in R/C applications.. -- The BBC: Licensed at public expense to spread lies. |
Paul,
You might want to check out what I built to do that sort of job with great precision: http://mysite.verizon.net/jdrocci/ Joe W3JDR "Paul Burridge" wrote in message ... On Wed, 25 Feb 2004 12:39:46 GMT, "W3JDR" wrote: Paul, I think you started off speaking about crystal oscillators, but you just mentioned a sweep generator. Can you tell us a little more about your application?? Certainly. I've just finished roughing out the block diagram, actually and will try to post it later for some constructive criticism. It's basically just to sweep a half-meg segment in the 40Mhz band for the purpose of testing filters to improve rx selectivity in R/C applications.. -- The BBC: Licensed at public expense to spread lies. |
Paul,
You might want to check out what I built to do that sort of job with great precision: http://mysite.verizon.net/jdrocci/ Joe W3JDR "Paul Burridge" wrote in message ... On Wed, 25 Feb 2004 12:39:46 GMT, "W3JDR" wrote: Paul, I think you started off speaking about crystal oscillators, but you just mentioned a sweep generator. Can you tell us a little more about your application?? Certainly. I've just finished roughing out the block diagram, actually and will try to post it later for some constructive criticism. It's basically just to sweep a half-meg segment in the 40Mhz band for the purpose of testing filters to improve rx selectivity in R/C applications.. -- The BBC: Licensed at public expense to spread lies. |
"Paul Burridge" wrote in message ... On Tue, 24 Feb 2004 12:30:12 -0700, Jim Thompson wrote: Aha! I just noted from Paul's post that "my" oscillator is called a two-transistor Butler. Wonder when that was conceived? I've been using the my direct-coupled version for 40 years. Interesting. This is the type I've decided to build as the basis for my next sweep generator attempt, since it's claimed the config is more amenable to being pulled than most others (although I won't be attempting to pull it anything like as much as my first abortive attempt using a Cmos-based inverter). Do you find it's a reliable and stable design, Jim? I assume if it wasn't you wouldn't still be using it! Why not use a VCO built from an LC oscillator? Its really easy to build one with a single transistor that sweeps your band. I built a simple one that looked like this: +------+--------+-------+ | | | | / | .-. C|L1 --- C1 --- | |R1 C| --- C3 --- | | C| / | | '-' | | | | +-------+------o antenna | | | | ___ | | |c --- C2 Vin o-|___|-+------+-----b| Q1 --- R4 | | |e | | | | | | | | | | | +-------+ | | | | .-. .-. --- | |R2 | | R3 C4 --- | | | | | '-' '-' | | | +------+--------+ Q1 = 2N3904 L1 = 0.5uH C1 = 20pF variable from 10pF to 80pF C2 = 4.7pF C3 = .22uF C4 = 1uF R1 = 47k R2 = 10k R3 = 1k R4 = 100 created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de I was able to sweep the band from 40MHz to 42MHz by first adjusting C1, then changing Vin (with a pot) to vary the output frequency. I built it on a solderless breadboard (!), and had no problems getting it to work. With your newfound PCB skills, should be a snap to get something like this working. I tested it by counting waveforms on my oscilloscope, so your mileage may vary. The resonant frequency is near f0 = 1/2.pi.sqrt(L1Ct) where Ct = C1 + C2||Cbe + Ca + Ccb Cbe is the capacitance between base and emitter of Q1, which is varied with base voltage; Ccb is the 'fixed' capacitance between emitter and base of Q1; and, Ca is the capacitance of the wire antenna. I'm unsure about how to calculate the power output of the thing, but I'm guessing its tiny. I was able to sweep the FM band (using a 0.1uH inductor) pretty reliably, and it knocked out radios in other parts of my house when I swept past them. The Q of the inductor should be as good as you can make. You can buy highQ inductors. At this value, an aircore is probably pretty good. Otherwise, your resonator won't stay on frequency. It'll drift with temperature, and probably the phase of the moon, as well. Regards, Bob Monsen |
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