If I remember correctly (and I am willing to admit up front that I might be mistaken on the specifics of your radio), yours would be crystal controlled. In the general case of crystal control, changing the crystals for the transmit and recieve are all that need to be done in the general sense ( you may need to fine tune your RF stages for accurate operation, but that is a normal "given", due to time (component values change), or changing some of the range over the existing set-up) Crystals should be available from Allied, or do some searches on the web for "transmit crystals", or some radio specific reference, otherwise you will end up with a bunch of "new-age" sites.
If you can inject a calibrated signal into your oscillator/exciter stages, you can sometimes use the injected signal in lieu of the crystal in some cases, but you need a very stable signal source, and you will want to isolate the signal source from the radio itself via capacitors on both sides of the signal input (ie signal hot, and ground). I have done this with a cheap crystal controlled scanner that I had, but there were quite a few limitations to it's ability. QST has run a few articles on this as I recall, but that would have been in the sixties and seventies, before the PLL circuits became cheap and plentiful. The older rigs have largely been forgotten about, so finding specific improvements for your radio(s) may be difficult. Unfortunately I am not an expert on all of the modifications on the old stuff.
Other than some of the starting points I have listed, the best bets are to keep searching if the links below are not quite right. Sometimes a site that shows up in a search engine, has the link that you need to find the information you are seeking. That is how I found approximately half those listed below.
The other suggestion is to pick up a few "sacrificial" units to test some of your own ideas.
Here are a few sites that have some modification information on specific rigs/PLL's. Some are easy, some require a change to the "logic" side of the PLL (the actions the normal rotary switch would make in binary for the "A", "B", "C", and "D" inputs.)
http://www.k1dwu.net/ham-links/
http://freenet.msp.mn.us/people/keacher/mods.html
http://w5gb.nmsu.edu/kc5kto/
ftp://oak.oakland.edu/pub/hamradio/mods/
They are listed in order of potential usefulness, either now, or in the future.
Below are two url's that address the PLL chips themselves, and some of the radios they can be found in. You may want to look into adding a Browning "Drake" into your collection, as there are numerous references for that unit.
http://www.superior.net/~haggis/pll1.html
http://www.superior.net/~haggis/pll2.html
http://www.min.net/~thom/drakelist/drakemod.html
: John:
: Thanks for the info.Ijust started this computer thing,
: and I don't know much about it.Please forgive me for
: any mistakes I may have made,I am not very good, but
: I am learning.
: I don't know much about those radios, but I do remem-
: ber when they were new.I always wanted one then,but I
: couldnot afford them.I can now,and I want to talk on
: one.This bunch I talk to now, likes to hang out on the
: "lowers",26.505 toabout 26.955Mhz.I have a Mark III
: and would like to convert it to operate on those lower
: channels.Everbody I have talked to doesn't know any-
: thing about them around here. If you could help me
: with this I would be very thankful.
: Also I am looking for a Tram D201 and D201A. If you know
: where one of these can be had, I again would be very
: thankful.
: Thank you very much;
: Michael McClellan
: "Michael Jay"
: If I remember correctly (and I am willing to admit up front that I might be mistaken on the specifics of your radio), yours would be crystal controlled. In the general case of crystal control, changing the crystals for the transmit and recieve are all that need to be done in the general sense ( you may need to fine tune your RF stages for accurate operation, but that is a normal "given", due to time (component values change), or changing some of the range over the existing set-up) Crystals should be available from Allied, or do some searches on the web for "transmit crystals", or some radio specific reference, otherwise you will end up with a bunch of "new-age" sites.
: If you can inject a calibrated signal into your oscillator/exciter stages, you can sometimes use the injected signal in lieu of the crystal in some cases, but you need a very stable signal source, and you will want to isolate the signal source from the radio itself via capacitors on both sides of the signal input (ie signal hot, and ground). I have done this with a cheap crystal controlled scanner that I had, but there were quite a few limitations to it's ability. QST has run a few articles on this as I recall, but that would have been in the sixties and seventies, before the PLL circuits became cheap and plentiful. The older rigs have largely been forgotten about, so finding specific improvements for your radio(s) may be difficult. Unfortunately I am not an expert on all of the modifications on the old stuff.
: Other than some of the starting points I have listed, the best bets are to keep searching if the links below are not quite right. Sometimes a site that shows up in a search engine, has the link that you need to find the information you are seeking. That is how I found approximately half those listed below.
: The other suggestion is to pick up a few "sacrificial" units to test some of your own ideas.
: Here are a few sites that have some modification information on specific rigs/PLL's. Some are easy, some require a change to the "logic" side of the PLL (the actions the normal rotary switch would make in binary for the "A", "B", "C", and "D" inputs.)
: http://www.k1dwu.net/ham-links/
: http://freenet.msp.mn.us/people/keacher/mods.html
: http://w5gb.nmsu.edu/kc5kto/
: ftp://oak.oakland.edu/pub/hamradio/mods/
: They are listed in order of potential usefulness, either now, or in the future.
: Below are two url's that address the PLL chips themselves, and some of the radios they can be found in. You may want to look into adding a Browning "Drake" into your collection, as there are numerous references for that unit.
: http://www.superior.net/~haggis/pll1.html
: http://www.superior.net/~haggis/pll2.html
: http://www.min.net/~thom/drakelist/drakemod.html
: : John:
: : Thanks for the info.Ijust started this computer thing,
: : and I don't know much about it.Please forgive me for
: : any mistakes I may have made,I am not very good, but
: : I am learning.
: : I don't know much about those radios, but I do remem-
: : ber when they were new.I always wanted one then,but I
: : couldnot afford them.I can now,and I want to talk on
: : one.This bunch I talk to now, likes to hang out on the
: : "lowers",26.505 toabout 26.955Mhz.I have a Mark III
: : and would like to convert it to operate on those lower
: : channels.Everbody I have talked to doesn't know any-
: : thing about them around here. If you could help me
: : with this I would be very thankful.
: : Also I am looking for a Tram D201 and D201A. If you know
: : where one of these can be had, I again would be very
: : thankful.
: : Thank you very much;
: : Michael McClellan
: : "Michael Jay"
: If I remember correctly (and I am willing to admit up front that I might be mistaken on the specifics of your radio), yours would be crystal controlled. In the general case of crystal control, changing the crystals for the transmit and recieve are all that need to be done in the general sense ( you may need to fine tune your RF stages for accurate operation, but that is a normal "given", due to time (component values change), or changing some of the range over the existing set-up) Crystals should be available from Allied, or do some searches on the web for "transmit crystals", or some radio specific reference, otherwise you will end up with a bunch of "new-age" sites.
: If you can inject a calibrated signal into your oscillator/exciter stages, you can sometimes use the injected signal in lieu of the crystal in some cases, but you need a very stable signal source, and you will want to isolate the signal source from the radio itself via capacitors on both sides of the signal input (ie signal hot, and ground). I have done this with a cheap crystal controlled scanner that I had, but there were quite a few limitations to it's ability. QST has run a few articles on this as I recall, but that would have been in the sixties and seventies, before the PLL circuits became cheap and plentiful. The older rigs have largely been forgotten about, so finding specific improvements for your radio(s) may be difficult. Unfortunately I am not an expert on all of the modifications on the old stuff.
: Other than some of the starting points I have listed, the best bets are to keep searching if the links below are not quite right. Sometimes a site that shows up in a search engine, has the link that you need to find the information you are seeking. That is how I found approximately half those listed below.
: The other suggestion is to pick up a few "sacrificial" units to test some of your own ideas.
: Here are a few sites that have some modification information on specific rigs/PLL's. Some are easy, some require a change to the "logic" side of the PLL (the actions the normal rotary switch would make in binary for the "A", "B", "C", and "D" inputs.)
: http://www.k1dwu.net/ham-links/
: http://freenet.msp.mn.us/people/keacher/mods.html
: http://w5gb.nmsu.edu/kc5kto/
: ftp://oak.oakland.edu/pub/hamradio/mods/
: They are listed in order of potential usefulness, either now, or in the future.
: Below are two url's that address the PLL chips themselves, and some of the radios they can be found in. You may want to look into adding a Browning "Drake" into your collection, as there are numerous references for that unit.
: http://www.superior.net/~haggis/pll1.html
: http://www.superior.net/~haggis/pll2.html
: http://www.min.net/~thom/drakelist/drakemod.html
: : John:
: : Thanks for the info.Ijust started this computer thing,
: : and I don't know much about it.Please forgive me for
: : any mistakes I may have made,I am not very good, but
: : I am learning.
: : I don't know much about those radios, but I do remem-
: : ber when they were new.I always wanted one then,but I
: : couldnot afford them.I can now,and I want to talk on
: : one.This bunch I talk to now, likes to hang out on the
: : "lowers",26.505 toabout 26.955Mhz.I have a Mark III
: : and would like to convert it to operate on those lower
: : channels.Everbody I have talked to doesn't know any-
: : thing about them around here. If you could help me
: : with this I would be very thankful.
: : Also I am looking for a Tram D201 and D201A. If you know
: : where one of these can be had, I again would be very
: : thankful.
: : Thank you very much;
: : Michael McClellan
: : "Michael Jay"