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#1
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5.0 - 5.5 mHz. VFO
I am looking for a contruction artical or some other starting point for
a solid state 5 to 5.5 mHz. VFO to use with my PSK-20. Hopefully somebody can point me to a contruction project, a kit or a source of a VFO. |
#2
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5.0 - 5.5 mHz. VFO
In article . com, k9jri wrote: I am looking for a contruction artical or some other starting point for a solid state 5 to 5.5 mHz. VFO to use with my PSK-20. Hopefully somebody can point me to a contruction project, a kit or a source of a VFO. Buying a copy of "Experimental Methods in RF Design" (the successor text to "Solid-State Design for the Radio Amateur") would be a very good place to start reading. These guys have written down a vast amount of very practical information and experience about how to do this sort of thing well and reliably. http://www.bright.net/~kanga/kanga/KK7B/uvfo.htm is a "universal" VFO kit which you might be able to adapt for your needs. Doug Demaw W1FB had another "universal VFO" design in his "QRP Notebook" (a great book if you can find a copy). You can buy a kit for it (board, semiconductors, air-variable cap, copy of the construction article) for $30 from http://www.danscloseoutsandspecialde...closeouts.html I've bought stuff from Dan a couple of times and have always been satisfied with what I've received. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#3
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5.0 - 5.5 mHz. VFO
I'm pretty sure every issue of the ARRL Handbook ever published has had
a schematic for just such a critter...haven't got one for several years, but they USED to have a design... Scott Dave Platt wrote: In article . com, k9jri wrote: I am looking for a contruction artical or some other starting point for a solid state 5 to 5.5 mHz. VFO to use with my PSK-20. Hopefully somebody can point me to a contruction project, a kit or a source of a VFO. Buying a copy of "Experimental Methods in RF Design" (the successor text to "Solid-State Design for the Radio Amateur") would be a very good place to start reading. These guys have written down a vast amount of very practical information and experience about how to do this sort of thing well and reliably. http://www.bright.net/~kanga/kanga/KK7B/uvfo.htm is a "universal" VFO kit which you might be able to adapt for your needs. Doug Demaw W1FB had another "universal VFO" design in his "QRP Notebook" (a great book if you can find a copy). You can buy a kit for it (board, semiconductors, air-variable cap, copy of the construction article) for $30 from http://www.danscloseoutsandspecialde...closeouts.html I've bought stuff from Dan a couple of times and have always been satisfied with what I've received. |
#4
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5.0 - 5.5 mHz. VFO
"k9jri" wrote in message ups.com... I am looking for a contruction artical or some other starting point for a solid state 5 to 5.5 mHz. VFO to use with my PSK-20. Hopefully somebody can point me to a contruction project, a kit or a source of a VFO. I think there was an article in QST within the last ten years that described a 5 to 5.5 mhz VFO. Mike |
#5
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5.0 - 5.5 mHz. VFO
My 1933 ARRL Handbook does not have a schematic for a 5 to 5.5MHz VFO,
much less a solid state one. Receivers that used 5MHz VFOs didn't start appearing until the mid '50s (judging from my meager collection of handbooks -- I only have eight spanning '33 to '76), with VFO SSB transmitters appearing about the same time. Someone who was actually alive at the time, or with a more extensive collection, may be able to contribute more. Scott wrote: I'm pretty sure every issue of the ARRL Handbook ever published has had a schematic for just such a critter...haven't got one for several years, but they USED to have a design... Scott Dave Platt wrote: In article . com, k9jri wrote: I am looking for a contruction artical or some other starting point for a solid state 5 to 5.5 mHz. VFO to use with my PSK-20. Hopefully somebody can point me to a contruction project, a kit or a source of a VFO. Buying a copy of "Experimental Methods in RF Design" (the successor text to "Solid-State Design for the Radio Amateur") would be a very good place to start reading. These guys have written down a vast amount of very practical information and experience about how to do this sort of thing well and reliably. http://www.bright.net/~kanga/kanga/KK7B/uvfo.htm is a "universal" VFO kit which you might be able to adapt for your needs. Doug Demaw W1FB had another "universal VFO" design in his "QRP Notebook" (a great book if you can find a copy). You can buy a kit for it (board, semiconductors, air-variable cap, copy of the construction article) for $30 from http://www.danscloseoutsandspecialde...closeouts.html I've bought stuff from Dan a couple of times and have always been satisfied with what I've received. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Posting from Google? See http://cfaj.freeshell.org/google/ "Applied Control Theory for Embedded Systems" came out in April. See details at http://www.wescottdesign.com/actfes/actfes.html |
#6
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5.0 - 5.5 mHz. VFO
"k9jri" wrote in message
ups.com... I am looking for a contruction artical or some other starting point for a solid state 5 to 5.5 mHz. VFO to use with my PSK-20. Hopefully somebody can point me to a contruction project, a kit or a source of a VFO. A Drake TR-5 PTO will work for that application. |
#7
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5.0 - 5.5 mHz. VFO
"k9jri" wrote in message
ups.com... I am looking for a contruction artical or some other starting point for a solid state 5 to 5.5 mHz. VFO to use with my PSK-20. Hopefully somebody can point me to a contruction project, a kit or a source of a VFO. You may wish to look at the WA6OTP PTO Kit - sounds like a possible fit. http://www.wa6otp.com/pto.htm |
#8
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5.0 - 5.5 mHz. VFO
Tim Wescott ) writes:
My 1933 ARRL Handbook does not have a schematic for a 5 to 5.5MHz VFO, much less a solid state one. Receivers that used 5MHz VFOs didn't start appearing until the mid '50s (judging from my meager collection of handbooks -- I only have eight spanning '33 to '76), with VFO SSB transmitters appearing about the same time. I'm sure that was exageration, but they do have a point. 5MHz VFOs have to be one of the more common items in the magazines and books over the years. Even before 5MHz came along for use with a 9MHz IF, the books and magazines were full of VFOs that could be shifted to 5MHz. There was a period when 6MHz was a common VFO frequency, for use with multiplying VHF transmitters, and those would be even easier to shift to 5MHz than a 3.5 or 7Mhz VFO. If someone is asking about a 5MHz VFO, they've not looked far. Now, the case may be that they are looking for something more specific, but in that case it makes sense to be specific. If someone wants out of the book, yes they won't find a 5MHz vfo in the 1933 Handbook. But, once they go that far back not only will they be tubes, but stability will likely be an issue. 1933 either predates the laws requiring "crystal-like" stability, or such laws were recently passed. Look at the diagrams from that era, and a lot of later concerns in construction haven't come into common place. Michael VE2BVW Someone who was actually alive at the time, or with a more extensive collection, may be able to contribute more. Scott wrote: I'm pretty sure every issue of the ARRL Handbook ever published has had a schematic for just such a critter...haven't got one for several years, but they USED to have a design... Scott Dave Platt wrote: In article . com, k9jri wrote: I am looking for a contruction artical or some other starting point for a solid state 5 to 5.5 mHz. VFO to use with my PSK-20. Hopefully somebody can point me to a contruction project, a kit or a source of a VFO. Buying a copy of "Experimental Methods in RF Design" (the successor text to "Solid-State Design for the Radio Amateur") would be a very good place to start reading. These guys have written down a vast amount of very practical information and experience about how to do this sort of thing well and reliably. http://www.bright.net/~kanga/kanga/KK7B/uvfo.htm is a "universal" VFO kit which you might be able to adapt for your needs. Doug Demaw W1FB had another "universal VFO" design in his "QRP Notebook" (a great book if you can find a copy). You can buy a kit for it (board, semiconductors, air-variable cap, copy of the construction article) for $30 from http://www.danscloseoutsandspecialde...closeouts.html I've bought stuff from Dan a couple of times and have always been satisfied with what I've received. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Posting from Google? See http://cfaj.freeshell.org/google/ "Applied Control Theory for Embedded Systems" came out in April. See details at http://www.wescottdesign.com/actfes/actfes.html |
#9
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5.0 - 5.5 mHz. VFO
If my memory is correct, the PSK-20 is used for, well... PSK.
That being the case, I think you might find it difficult to get adequate frequency stability using a free-running VFO. Since the PSK decoder software automatically gives you about 2KHz of tuning in software, a PLL approach would be quite easy and should produce a clean spectrum if done properly. I think a DDS solution would also be quite good for this application Joe W3JDR "k9jri" wrote in message ups.com... I am looking for a contruction artical or some other starting point for a solid state 5 to 5.5 mHz. VFO to use with my PSK-20. Hopefully somebody can point me to a contruction project, a kit or a source of a VFO. |
#10
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5.0 - 5.5 mHz. VFO
k9jri wrote:
I am looking for a contruction artical or some other starting point for a solid state 5 to 5.5 mHz. VFO to use with my PSK-20. Hopefully somebody can point me to a contruction project, a kit or a source of a VFO. The VFO used in the "Progressive Communications Receiver" by W7XZOI & K5IRK, (QST 11/81; various ARRL Handbooks inc. 1990) is a good stable general purpose JFET Hartley circuit VFO. It can be built to cover frequencies from 2.5 to 10 Mhz. range. The article has charts and calculations to derive component values for the tuning capacitor, and inductor, etc. I've built one to cover exact range you desire. As long as one follows good design practices, such as: use NP0 capacitors only; tuned circuit should be lightly coupled to the FET - i.e. use a small value like 2-3 pF cap., air variable or small ceramic; the VFO will be stable. Power output is around +5 to +8 dBm into 50 ohms depending upon type of dual gate MOSFET used for the buffer amp. Jeff |