Ten Tec Argonaut pages (page 2)
I first bought an argonaut 505 from VE3UR (uncle Ray) in Toronto area. I really got a kick out of
using it.
I recently put my 505 on the bench (April 08) and repaired one problem very easily. I changed the
two audio output transistors. Now the rig has audio output again..but still cannot receive signals
on its fundamental frequency. Below I made a little video with my new camera. It shows a simple
technique for seeing if the radio receiver has any life in it at all. My argonaut has a 9 mhz IF and
so I used my MFJ antenna analyser at 9 mhz.
The radio does receive the 9 mhz signal and it converts it to intelligent audio. So the problem
with the receiver must be in the front end circuitry ahead of the IF. Possibly in the mixer circuit.
NOTE: the little movie clips I'm making take a bit of time to set up and run.
I first bought an argonaut 505 from VE3UR (uncle Ray) in Toronto area. I really got a kick out of
using it.
I recently put my 505 on the bench (April 08) and repaired one problem very easily. I changed the
two audio output transistors. Now the rig has audio output again..but still cannot receive signals
on its fundamental frequency. Below I made a little video with my new camera. It shows a simple
technique for seeing if the radio receiver has any life in it at all. My argonaut has a 9 mhz IF and
so I used my MFJ antenna analyser at 9 mhz.
The radio does receive the 9 mhz signal and it converts it to intelligent audio. So the problem
with the receiver must be in the front end circuitry ahead of the IF. Possibly in the mixer circuit.
NOTE: the little movie clips I'm making take a bit of time to set up and run.
Here are a couple of schematics of the Argonaut modification to 30 meters. The 505 circuitry will not allow it to be converted to 30 but
either the 515 or the 509 can be. I want to leave my 515 as it is ..and so I might eventually get around to doing this mod on one of my
509s.
30 meters is a cw only band and I must regrettably admit..I don't operate it. I should operate it as it would likely have much less qrm
than 40 meters. 30 meters is a no contest band and so ..if you are looking for a quiet place during sweepstakes or cq ww..try 30.
either the 515 or the 509 can be. I want to leave my 515 as it is ..and so I might eventually get around to doing this mod on one of my
509s.
30 meters is a cw only band and I must regrettably admit..I don't operate it. I should operate it as it would likely have much less qrm
than 40 meters. 30 meters is a no contest band and so ..if you are looking for a quiet place during sweepstakes or cq ww..try 30.
It is a pretty simple mod.
Years ago..back around 1975, I had an hw16 and I modified the hw16 for 20 meters.
That mod worked fine and was easy to do.
Years ago..back around 1975, I had an hw16 and I modified the hw16 for 20 meters.
That mod worked fine and was easy to do.
This is the Argonaut 509 front end board. It is both a receiver front end and transmitter front end. This board is a little difficult to work on. It
is not plug in style like the rest of the boards. I once blew the receiver MPF 132 Q1 and it was a little difficult to get at to replace.
Reference the mod for 30 meters (as per above)..the 28 mhz circuit below is the one to modify with the 91 pf capacitors.
These transformers for 7 through 28 mhz are double tuned slug tuned coils. I m going from memory here..but I think each coil has two slugs
and the circuit is adjusted for an optimal passband at the selected band of operation.
Some of these circuits may be a little difficult for the average ham to work on. I have a sweep generator, spectrum analyser and 100 mhz
scope at my disposal. The 3.5 mhz band pass filter is a more conventional qrp circuit. We see these kind of filters for many of the qrp
homebrew projects. L1 and L2 are fixed wound torroids
Note: despite the simplicity of the receiver front end circuit, I find it works quite well. Nice and sensitive and with a "presence" on receive.
I don't find the receiver overloads all that bad either.
I use the outboard ten tec audio filter that plugs into the back of my 515. It works at the low level audio stages and does a nice job at
tightening up the selectivity.
is not plug in style like the rest of the boards. I once blew the receiver MPF 132 Q1 and it was a little difficult to get at to replace.
Reference the mod for 30 meters (as per above)..the 28 mhz circuit below is the one to modify with the 91 pf capacitors.
These transformers for 7 through 28 mhz are double tuned slug tuned coils. I m going from memory here..but I think each coil has two slugs
and the circuit is adjusted for an optimal passband at the selected band of operation.
Some of these circuits may be a little difficult for the average ham to work on. I have a sweep generator, spectrum analyser and 100 mhz
scope at my disposal. The 3.5 mhz band pass filter is a more conventional qrp circuit. We see these kind of filters for many of the qrp
homebrew projects. L1 and L2 are fixed wound torroids
Note: despite the simplicity of the receiver front end circuit, I find it works quite well. Nice and sensitive and with a "presence" on receive.
I don't find the receiver overloads all that bad either.
I use the outboard ten tec audio filter that plugs into the back of my 515. It works at the low level audio stages and does a nice job at
tightening up the selectivity.
click here for PAGE 3
about the older
ARGONAUTS
about the older
ARGONAUTS
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Picture of me Field Day 2006. I set up a table in my garden
shed and strung out a wire and made a few contacts with the
515 barefoot. Note the generator on the shelf. I used that to
charge my deep cycle battery. I also worked on my TGM mini
beam before Field Day and got it assembled in the back yard.
I often use Field Day weekend to work on antenna projects
and try them out. I mostly operate in my back yard. Field Day
2008 was an exception. I went out with the Elliot Lake ARC.
shed and strung out a wire and made a few contacts with the
515 barefoot. Note the generator on the shelf. I used that to
charge my deep cycle battery. I also worked on my TGM mini
beam before Field Day and got it assembled in the back yard.
I often use Field Day weekend to work on antenna projects
and try them out. I mostly operate in my back yard. Field Day
2008 was an exception. I went out with the Elliot Lake ARC.