Argonaut 505

[W3WN]

Like I need ANOTHER ham radio project to work on...

Last year at WASHFest, my friend Bill W3WH bought a Ten Tec Argonaut 505, with the accesory CW filter. Bill was told that the unit was working just fine.

It wasn't. No receiv. From what Bill said, it sounds like the "90197 RF Front End Board" may be shot.A trip to Sevierville revealed that it has some major audio problems (exactly what I don't know yet) and was unrepairable by the factory; combination of some parts no longer available, and the cost to repair would well exceed the value of the rig.

Bill had it on our table at WASHFest this year. And we ended up swapping for it, as I had a few things he wanted. Well, if nothing else, it will look nice on the shelf next to the TT PM-2B, the Ameco AC-1, and some of the other little QRP rigs I've collected recently.

Suffice to say, if anyone has a 505 out there that they're parting out, sooner or later, I do want to talk about possibly obtaining that board, possibly other parts as well.

[K7SGJ]

Just curious, do they give any indication of what was wrong other than just generalizing?

[W3WN]

I'm sure they told Bill. He couldn't remember the details, and he was going to find the paperwork.

[N8YX]

Let me know what you need in the way of parts. I may very well have them.

[W3WN]

Let me know what you need in the way of parts. I may very well have them.

No problem. I just need time to look at the schematics and do some basic trouble shooting.

I didn't see you, so I'm presuming you guys didn't make it down. Pity, we had a good show. Our two big commercial vendors, plus the local lady who does the embroidery, have already committed to their tables for next year... so we've already presold 23 out of 70 tables!

[N8YX]

No problem. I just need time to look at the schematics and do some basic trouble shooting.

I didn't see you, so I'm presuming you guys didn't make it down. Pity, we had a good show. Our two big commercial vendors, plus the local lady who does the embroidery, have already committed to their tables for next year... so we've already presold 23 out of 70 tables!

Nope - didn't make it. 'DSG had a rather harrowing drive back from her mother's place on Saturday evening and was tripped out as a result. We'll be at Breezeshooters, though.

[W3WN]

Yeah, I saw the weather forecast Friday night, and the news reports on some of the whiteouts up by I-80. We were sweating bullets on that through Saturday night...

According to the schematics:


Of course, there's no diagram (in the downloaded copy) of the RF Front End Board.

Transistors on some of the other boards:

90195 RF Power Output Board:
Q1, Q2: 2N2631

90184 IF Board:
Q1 2N5134
Q2 40823
Q3 2N5133
Q4 2N5134
Q5 2N5133
Q6 2N5134
Q7 2N5134

90186 Audio Power Amp board:
Q1 2N5139
Q2 2N5133
Q3 2N5128
Q4 2N4105
Q6 2N5134

Oscillator Sub-Assembly:
Q1 2N5128
Q2 2N5134
Q3 2N5134
Q4 2N5134

A lot of these transistors are used throughout.

Let me know which, if any of these, you have (or equivalent substitute). And I'll sit down next day or three and go through the manual to see what other ones the unit needs. I'm not too worried about diodes, caps, and resistors, but these will be the critical components (famous last words)

[N8YX]

Yeah, I saw the weather forecast Friday night, and the news reports on some of the whiteouts up by I-80. We were sweating bullets on that through Saturday night...

According to the schematics:


Of course, there's no diagram (in the downloaded copy) of the RF Front End Board.

Transistors on some of the other boards:

90195 RF Power Output Board:
Q1, Q2: 2N2631

90184 IF Board:
Q1 2N5134
Q2 40823
Q3 2N5133
Q4 2N5134
Q5 2N5133
Q6 2N5134
Q7 2N5134

90186 Audio Power Amp board:
Q1 2N5139
Q2 2N5133
Q3 2N5128
Q4 2N4105
Q6 2N5134

Oscillator Sub-Assembly:
Q1 2N5128
Q2 2N5134
Q3 2N5134
Q4 2N5134

A lot of these transistors are used throughout.

Let me know which, if any of these, you have (or equivalent substitute). And I'll sit down next day or three and go through the manual to see what other ones the unit needs. I'm not too worried about diodes, caps, and resistors, but these will be the critical components (famous last words)

Lookie here:

http://www.ebay.com/itm/2N5139-Transistor-x-1-pieces-/150583576631?pt=LH_DefaultDomain_0&hash=item230f7b 0837

http://www.ebay.com/itm/2N5134-Trans...item230f7b07eb

http://www.ebay.com/itm/PCK-10-2N513...item5ae363f212

http://www.ebay.com/itm/2N5128-npn-t...item2318b12bf6

http://www.circuitspecialists.com/mps5128.html

http://www.smallbearelec.com/Detail.bok?no=492

http://www.talonix.com/shop/item.aspx?itemid=3389

http://www.circuitspecialists.com/mps5139.html

http://www.alltronics.com/cgi-bin/ca...ry=63&start=36

[W3WN]

Well, I caught a small break. Bill can't find the paperwork he got back from Ten-Tec, but he posted a query to the Ten Tec reflector last March. The 2N4105 & 2N4106 transistors in the audio power amp need replaced. Alltronics for one has them. So I'm going to check and see how many I need and order them (plus a few extra, just in case) right after payday.

One step at a time. I just hope the finals aren't shot, it appears that the originals (2N2631) and their replacements (2N3553) are now made out of Unobtanium.

[N8YX]

One step at a time. I just hope the finals aren't shot, it appears that the originals (2N2631) and their replacements (2N3553) are now made out of Unobtanium.

I would redesign the PA and look at using an MRF device or its equivalent. Have a look at an NTE236 for starters, or a 2SC1969.