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Post by husker on Dec 22, 2017 12:57:23 GMT -5
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Post by husker on Dec 13, 2017 1:02:41 GMT -5
I would take one in a minute!
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Post by husker on Dec 11, 2017 0:14:00 GMT -5
LOL, yes Ron has been helping me try to figure out this crazy radio issue. He got tired of attempting to use the wrong schematic so he decided to reverse engineer the entire thing. VERY nice work!!
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Post by husker on Dec 9, 2017 23:01:11 GMT -5
I am sure many of you know there are differences between the fixed and non fixed bias versions of this radio. I have been told that Tram produced a "addendum" for the fixed bias versions schematic. If there is such a beast does anyone have it I could see? There seem to be more questions then there are answers and I really need a schematic to try to trouble shoot.
If any one has this item please let me know.
thanks!
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Post by husker on Dec 9, 2017 17:46:50 GMT -5
I never removed them on this BA brd. I have a few extras and I was using a non fixed bias BA when I attempted to change the bias.
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Post by husker on Dec 9, 2017 2:19:58 GMT -5
I am getting a reading of -2.9 volts on pin 8 of v603. I had to remove the tube as something is making it cherry. I removed the 10 ohm that was behind v603 and jumped it. I am also reading -2.9 on pin 57.
The crazy current draw (including bad hum) and the over heating 6l6 worries me.
Do you by any chance have the amendment for the fixed bias version? I was told there was an amendment schematic?
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Post by husker on Dec 6, 2017 17:40:09 GMT -5
Cool, I have to start somewhere
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Post by husker on Dec 6, 2017 13:52:35 GMT -5
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Post by husker on Dec 5, 2017 0:27:58 GMT -5
ok, so I have replaced all the caps, all "problematic" resistors, checked tubes. Everything checks out, but still no audio. Couple questions, I do have a re built audio brd I could swap in, but man that's a lot of work. And second, how would I know of I did indeed have a bad mode switch? That's even more fun to swap out by the looks of it!
thanks guys!
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Post by husker on Dec 2, 2017 2:25:21 GMT -5
well,when I was trying to test voltage on different parts, the power was erratic, it would read say 452 volts, then drop to almost nothing then come back, I wonder if this resistor was loose and would touch off and on to give me those voltage readings?
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Post by husker on Dec 1, 2017 23:42:27 GMT -5
Does your BA board have a fuse on it? The factory-supplied 1/10-Amp fuse (100 mA) has an incredibly thin element. If a continuity test says it's okay, this isn't the problem. Just can't trust the calibrated eyeball alone. If this fuse trips, you will have no audio at all, AM or SSB, neither transmit nor receive. If you are missing audio on only one mode, like AM (and NOT SSB) your problem is NOT located on the audio board. Receive audio for ALL modes is delivered to the audio board from the mode selector. A fault on the audio board will affect all receive modes equally. A loss of just AM or SSB receiver audio will reside on the main receiver board, or the mode selector and its wiring. Never, every assume that a 40 year-old radio has JUST ONE problem at any given time. The odds don't favor it. Avoid the temptation to use a fuse bigger than 1/8 Amp, or 125 mA. We find that the original 1/10-Amp size can be tripped from overmodulation alone. The bigger the fuse, the more smoke gets released in the event of a fault. The more smoke you let out, the more it costs to put back in. Won't work until enough fresh smoke is installed. 73 Ok, so I decided to do a little old fashion trouble shooting, not knowing nearly what many of you know, but never the less try. I was testing resistors (R3&4) and I happened to touch R6, the big 100ohm 7 watt resistor. Well, to my surprise it was loose, I touched it and one end came up in my hand. it appears that one leg wasn't connected fully through the hole in the brd or it had come loose. It looked a tad worse for wear, so I went ahead and ordered a new one. I can only assume this not being connected would lead to some pretty interesting audio issues?
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Post by husker on Nov 28, 2017 0:03:02 GMT -5
Does your BA board have a fuse on it? The factory-supplied 1/10-Amp fuse (100 mA) has an incredibly thin element. If a continuity test says it's okay, this isn't the problem. Just can't trust the calibrated eyeball alone. If this fuse trips, you will have no audio at all, AM or SSB, neither transmit nor receive. If you are missing audio on only one mode, like AM (and NOT SSB) your problem is NOT located on the audio board. Receive audio for ALL modes is delivered to the audio board from the mode selector. A fault on the audio board will affect all receive modes equally. A loss of just AM or SSB receiver audio will reside on the main receiver board, or the mode selector and its wiring. Never, every assume that a 40 year-old radio has JUST ONE problem at any given time. The odds don't favor it. Avoid the temptation to use a fuse bigger than 1/8 Amp, or 125 mA. We find that the original 1/10-Amp size can be tripped from overmodulation alone. The bigger the fuse, the more smoke gets released in the event of a fault. The more smoke you let out, the more it costs to put back in. Won't work until enough fresh smoke is installed. 73 Ok, but I shouldn't have a fuse on the BA brd if I have a fixed bias should I? I just have jumpers. It is both AM and SSB, no receive. So you would look at the mode selector?
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Post by husker on Nov 27, 2017 22:07:00 GMT -5
OMG!!! lol, I couldnt agree more
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Post by husker on Nov 26, 2017 16:09:04 GMT -5
Hi! So the original issue was a lack of AM receive. Then I tried something I shouldn't have without a better understanding of what I was doing ( the fixed bias change of cutting the yellow wire and the jumper of the cut trace, and my BA brd didn't have the jumpers to begin with ) and now I have zero receive audio. HELP lol
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Post by husker on Nov 26, 2017 12:28:26 GMT -5
I never removed them. See, part of whatr was confusing and may have lead to more issues in different ares (?) was I followed the simple instructions of the 100,000 check list I attached to a previous thread. That is all on me, I should have asked for more information prior to removing anything. So my BA brd didn't have any jumpers, it has all the resistors in place. Also, the BA brd has been redone as have the two multi-section caps. So at this point the radio is back to square one, but I have added the missing resistor I found gone and replaced a couple others that looked over heated. So, ...help please lol..the tubes have been checked (actually replaced a couple with known good ones) and they appear to be good. Any thoughts as to why I get no audio? It's like looking for a needle in a haystack sadly
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Post by husker on Nov 26, 2017 0:52:26 GMT -5
lol, I see now. No, I didn't do the 10 Ohm removal for the bias, I did it following the 100,000 mile check up sheet. My point was that was the only other thing I did besides clip the yellow wire and jump the trace cut. Am I making better sense now?
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Post by husker on Nov 24, 2017 22:22:05 GMT -5
Correct, in back of the audio 6L6GC
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Post by husker on Nov 24, 2017 12:13:27 GMT -5
As am I, the 100,000 mile check up states to remove it and place a jumper in it's place. The manual I have doesn't show a resistor there, but both my 201a's have i there. Both run the 6L6 tube on the audio brd. The only thing that still is different from the stock config is this resistor.
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Post by husker on Nov 24, 2017 11:22:34 GMT -5
yes sir, AM was not very good, but SSB was great
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Post by husker on Nov 24, 2017 0:37:56 GMT -5
I had this fixed bias setup, I followed the "fix" by removing the 10 ohm resistor and the yellow wire, then jumping the trace back at the cut. When I fired up the radio...zero audio. Any ideas?
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Post by husker on Nov 21, 2017 17:34:10 GMT -5
I did find these....are they any good?
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Post by husker on Nov 20, 2017 22:53:01 GMT -5
Another question, I was reading that there should be no 10ohm 1/2 watt resistor directly behind the 6L6GC tube, if there is I should remove it and put a jumper there. The owners manual I have it only shows a jumper there....so should I remove this resistor? What good did it do in the first place? EDIT, never mind, I do have or DID have the fixed bias. I removed the yellow wire and jumped the trace cut.
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Post by husker on Nov 20, 2017 14:50:49 GMT -5
thank you very much! I can't thank all of you for all your help!!!
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Post by husker on Nov 20, 2017 11:31:54 GMT -5
Thank you for your response guys! Is that 100,000 mile replace list published anywhere?
thanks again
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Post by husker on Nov 19, 2017 0:00:20 GMT -5
Woah........there is NO R507 resistor? ? Can anyone think of any reason why that would be removed? It's not jumped, just simply gone!
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Post by husker on Nov 18, 2017 17:28:24 GMT -5
lol, no doubt guys! It appears someone has already gone through this one one time already, but I don't think they went far enough. What I meant about carrier on SSB was modulation driven, it was late and I was getting tired.
Is there a check list out there for the 100k mile tune up?
thanks guys, you are awesome!
Oh, I did find the original owner's "transmitter ID Card" taped to the inside of the top cover. His name was Felise Lisi from NY. I tried to see if I could contact him, but he passed in early 2000.
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Post by husker on Nov 18, 2017 2:12:56 GMT -5
well, my project Tram came back alive..kinda lol. So I have minimal AM audio (had to turn the volume all the way up) but SSB has good audio. There is ZERO carrier on both AM and SSB. I am keeping at it ..
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Post by husker on Nov 17, 2017 17:35:55 GMT -5
Interesting, that would make sense. Both do look a tad over heated, but 320 is just a shell. LOL, the colors are gone Thank you!!!!!!
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Post by husker on Nov 17, 2017 1:18:14 GMT -5
I was tracing back my issues over lost receive on a 201a I had sitting in my shack for a while. Seems R320 is pretty much smoked...what would cause that resistor to fail (it appears to have gotten very hot). It looks like it had been replaced at one time, the power side has been reworked as well (new BA brd). I really would like to know what may have happened so when I replace it the same thing doesn't happen again.
I was just wonder if anyone (Sandbagger) can give me a clue where to go to find the reason why R320 over heated and failed.
thanks
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Post by husker on Oct 7, 2017 0:40:28 GMT -5
Great! I will check that. I have this old girl running strong, now on to my Browning Mk III. It has no receive either.
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