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Nomad, Ok I had some time to mess around with this again finally. Pulled tr49 and still slammed carrier. Tr51 brand new and tr50 new. Just wanted to give an update,thanks.

Put a new tip42c in at tr50. I'm back to a maxed out dead key with no modulation. Also tp7,8,9 back to 12.5+v. Need a little guidance on tracking this fault. Thanks

I already switched the tip31 out for the original transistor since it tested good. Thanks

Yes it's a 1869 pnp so I think it might of had the voltages flip flopped. Tr51 is 13.5 3.2, 14. That's rear to front solder side up. So that doesn't look good either then. Ok thanks for the help, have a good one.

13v, 3.1, 12.5 (b,c,e)

It tested good so that's why I put it back in.

Ok thanks Sonoma for that. I swapped back in the original for tr50 and also replaced c212. I now have modulation!! But now no carrier, nothing showing up on wattmeter. I can hear myself finally though on my monitor radio. Also seems like all the voltages fell back into place.

I just put tr51 and 50 back in and now voltage is Over 13v at tp7,8,9. Also voltage readings are high on tr51 and 50 according to the voltage chart.

Well I took out tr50 and tr51 and voltage dropped to nothing at tp7 ,8,9. They are already new transistors tip31 and a tip36. They both tested fine on my atlas semiconductor tester as well. So any thoughts? I have a scope as well if there are any tests I can do with that to hunt down the gremlin.

Sounds like a plan. I'll get to it later today and report back. Thanks for pointing me in the right direction.

Ok so leave tr51 out of circuit as well or just take tr50 out? I already replaced tr51 , tr50 and tr49. When you say drop to "zero" I'm guessing you mean voltage and not watts? Thanks

Ok working on a radio for a friend. Its in good shape and no mods done to it that I can see. Problem is I'm getting a full blown carrier with zero modulation. I cannot adjust carrier with vr pots and it doesn't matter if it's in high or low power. I already changed tr51. Took that out of circuit...

Very nice. Yes pictures are always welcome haha.

Thanks Bow that's exactly what I was looking for. I know there are ways to key up a mic without a keyer box such as a rubber band as someone suggested. But I wanted a separate switch, I don't know call me crazy I guess. Just have to find a little project box now.

Just wondering if any has ever made up a box with a on/off switch to keep a radio keyed up while doing testing? I'm thinking about trying to put together something so that when testing on the bench I can have both hands free instead of trying to hold the ptt. Thanks

Just wanted to give an update. I put r104 back and removed r105,like you said. I could not get the vr pot to work. So I thought just for the heck of I'll try it at r104. Bingo it worked, direct swap. Also I did the resistor across c90 and really like how it turned out. What's the capacitor to...

Wow NZ8N that's great information!! That's exactly what I was looking for. Yes I do have a scope so I will be able to adjust everything like you described. Awesome little tip about putting that resisrlt across c90. For the VR pot , one leg goes to ground, one leg to the diode that I add and...

Thanks I appreciate it.

I'm not sure on the value of r104. Yes there is a spot screened onto the board for a vr pot near the transformer. It's to the right of it and towards the top. You thinking that spot could be for the amc pot?

I saw this but all it really tells me is q39 is mod limiter, which is still in the radio.