• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

Tram D-80 circuit trouble

LtStarsurfer

New Member
Jan 30, 2023
1
0
1
Tampa FL
I have a Tram D80. When I turned it on it powers up, no tx or rx but would after letting it sit I hear a little pop and then does. I've look through it and did find a pwr wire loose that I resoldered. Cleaned it up and now when I've powered it on it seem to have improved but not corrected it, when key'd the power out is 5w but voice is none existent unless I turn the mic gain all the way up and use a D104 handheld mic turn up all the way. It does show some modulation at that point too and I'm able to hear transmission on a different CB and transmissions from that other radio. I've look at the board which is seems to be the same as the Pres Wash/ Uniden. I have both schematics and they do seem the same. I did find that the center connection on TR 32 is cut (2sc945A-O) disconnecting the collector I believe since most parts are Japanese. I was told that this should bypass and provide max voice out all the time and why it was done. Down the line I have TR 29 (2SC458PGC and 28 (2SC945AO). Reading back I've see that some of these old ones bad news and should be replaced. I'm a novice but believe they check ok using a multimeter that has a diode check. I'm not sure about the ICs. What I see down the line is AN612. All that said, I have noticed while checking for bad solder points, When I touch a pin on IC1 (UHIC007) it switches to TX and if I was unable to with the mic, It switches over to where I can again. (hope that makes sense) Now I'm wondering if it's a ground and where to look or am I going to need to find a replacement for this IC.
Any help from you all that are way smarter than I.
 

I'm not a Tram expert, and have only fixed a reverse polarity protection diode and replaced the smoked filter inductors on one, once. So I won't be guiding you through everything you're having trouble with since I'm not all that smart.

I will say that it sounds like a cold solder joint somewhere near or on the leads for IC1. So you probably shouldn't need to replace it, just reflow the solder on the IC pins and some of the components nearby.

If you do need to replace it, however, there's still a few of the original parts out in the wild but you you'll have to hunt for them and expect to pay a premium. In addition, there's the also discontinued NTE1262 that's supposed to be an acceptable substitute. They stopped making both when everyone went lead free, it appears.

There may also be a lead-free alternative, UHIC-070. Can't verify as I haven't tested it, but I've seen one reference to it being usable.

If you do go shopping for any of those parts, expect to pay $25.00 or higher.

Now I'll shut up and let the guys who actually know what they're doing chime in.
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ Wildcat27:
    Hello I have a old school 2950 receives great on all modes and transmits great on AM but no transmit on SSB. Does anyone have any idea?
  • @ ButtFuzz:
    Good evening from Sunny Salem! What’s shaking?
  • dxBot:
    63Sprint has left the room.
  • dxBot:
    kennyjames 0151 has left the room.