TRAM D201 non handwired no AM RX

[Crambone]

i have a D201 that doesn’t have receive in AM or I can barely hear a tone with volume FCW, works good in LSB & USB. Has power out in AM and modulation. I removed all the tubes and checked and they all tested good. I recapped (electrolytics) the entire radio and all the HV resistors hoping it would correct the issue but no luck.
I looked at the alignment procedure and decided to first look at the 455 KHz AM alignment first. When I put a .01 on V302 pin 2 and inject a 455 KHz tone I’m not getting any audio at the speaker at all. I’m not sure where to look now?

 

[nomadradio]

Making sure you have 130 Volts DC on pin 1 of V302 would be next. The plate load resistor R310 has a bad habit of going open.

If that checks okay, pin 5 of V400 should be roughly 100 Volts. Pin 5 closer to 240, and pin 7 really ought to be under 3 Volts.

If all of those check okay, that leaves V401. The voltages shown on the schemo are close enough. If all those check okay, suspect a bad IF transformer.

Or try feeding 455 kHz directly into pin 3 of V401. Would at least allow you to peak both slugs in T401. If one or both won't peak, that's a fault right there.

If T401 passes this test, feeding pin 1 of V400 would be next. Now you can see if T400 shows a proper peak on each slug. Or not.

Which kind of 455 kHz ceramic filter does this radio have? The round beige 2-pin resonators? Or the square black one with 3 legs? Or some of each? Tram did not stop using the old Clevite round 2-pin filters right away. Some radios had one black filter, and a couple of the beige ones. Earlier production had (I think) six of the round 2-pin filters. The last production had two of the black square Murata-type ceramic filters.

The 5.8015 MHz crystal X300 has to run to get any AM receive. The plate resistor for that oscillator circuit is R322, a 100k 2 Watt. We replace it with a 5-Watt part. If you have a radio that can receive 5.8015 MHz handy, you can confirm whether or not that crystal is running.

But that's the hit parade. Decent chance the trouble is on that list, assuming that it's only one fault.

Maybe.

73