Hi everyone.

Made great progress, all alignment looked fine until I got to the bandpass tuning pots on the power supply board, moving them all, nothing happened, 10v adjust ok.

Took the board out, cleaned the molex connectors, resoldered a few iffy joints and replaced.

Still the same, putting my meter on the centre pin of each pot I adjusted them to 6.1 volts each as a diagnostic tool.

Turned the TR7 over and measured all the pins on the socket, wr to earth.

All fine, the 6.1v appeared on each required pin.

Looking in the manual it's very blurred on the wiring diagram.

Before I trace every wire, has anyone got any idea on the link to the PBT board.

The fact that all modes has this fault may be the clue that is going over my head.

Thanks

Mike

G3ZCC

?

Matteo, you are not crazy but you must be determined. The distortion tells me something is amiss with the AGC system -- incorrect AGC voltage or bad interstage coupling caps putting B+ on the grids.

?

As for T11, the easiest way is to watch eBay for the part to show up. You can certainly build a new coil, or perhaps adapt a new part that you find with Google, but that will be more work.

?

Good luck, and keep us posted.

?

Dave

I have one of those little testers.? Capacitor checks seem to be close
to what my much older Sencore LC75 meter shows.?? The Sencore meter will
check leakage at various voltages. Not able to do that with the little
tester.

Good luck with your project.


73

Stan
KM4HQE



On 1/31/25 14:43, DavidC KD4E via groups.io wrote:

Received the caps and an ESR tester.

So far, so good ...

See attached pic.

On 1/27/25 20:55, Tony Sokol via groups.io wrote:

? ? ?I just wanted to make a comment here. David spent a bit of time
making sure he was ordering the right parts. I think “wasting money “
with the kits is a bit harsh. That extra money amounts to paying
someone to source and confirm the various components which is not
second nature like it is to us old far…er…folks. I’m really glad to
see younger folks with a desire to learn which end of the soldering
iron to pick up.
? ? ? By the way, I was in the 7th grade when I first picked up a
soldering iron. :-) ?Got my call in ‘54. Where the heck does the time
go. Oh wait, that’s what old people say. ;-)

Tony - W9JXN

On Jan 31, 2025, at 4:40?AM, Jim VE7RF via groups.io <jim.thom@...> wrote:

?

AFAIK,? the R4C used a different tap on? (I think) the IF section, to increase the gain when using the CW filters, due to their higher, inherent insertion loss.?

On a similar note,? years ago, I bought a? new 125 hz? xtal filter from Inrad, for use in my yaeus's..... and the insertion loss was 9-10 db worse then the yaesu 250 hz filter.? It's semi useable.? I ended up removing it, and replaced with? the oem? 250 hz.?

?

Received the caps and an ESR tester.

So far, so good ...

See attached pic.

On 1/27/25 20:55, Tony Sokol via groups.io wrote:

? ? ?I just wanted to make a comment here. David spent a bit of time
making sure he was ordering the right parts. I think “wasting money “
with the kits is a bit harsh. That extra money amounts to paying
someone to source and confirm the various components which is not
second nature like it is to us old far…er…folks. I’m really glad to
see younger folks with a desire to learn which end of the soldering
iron to pick up.
? ? ? By the way, I was in the 7th grade when I first picked up a
soldering iron. :-) ?Got my call in ‘54. Where the heck does the time
go. Oh wait, that’s what old people say. ;-)

Tony - W9JXN

? ? ?I just wanted to make a comment here. David spent a bit of time making sure he was ordering the right parts. I think “wasting money “ with the kits is a bit harsh. That extra money amounts to paying someone to source and confirm the various components which is not second nature like it is to us old far…er…folks. I’m really glad to see younger folks with a desire to learn which end of the soldering iron to pick up.
? ? ? By the way, I was in the 7th grade when I first picked up a soldering iron. :-) ?Got my call in ‘54. Where the heck does the time go. Oh wait, that’s what old people say. ;-)

Tony - W9JXN

That number looks familiar. I’ve been meaning to post my spreadsheet of available transistors that I sorted from a tacklebox full of randomly-mixed parts.?

I will try and remember to do this shortly. Feel free to nag me if I forget.?

Steve Wedge, W1ES

Time flies like an arrow. Fruit flies like a banana.

Sent from for iOS

On Fri, Jan 31, 2025 at 10:24, Jim Harris via groups.io < radiove1rb@...> wrote:

Thank you Jim for that bit of information. ,I replaced the transistor a few years ago working on it but just got around to working on it again.

Regards, Jim

On Fri, Jan 31, 2025 at 10:37?AM Jim WA9Z via <jim= [email protected]> wrote:

Our records show having replaced a few of these over the years.? BM and the buffer.? Almost sounds like it qualifies for common failure analysis. The 2n4427 has unique properties, not easily substituted.? ?

Jim WA9Z

Exline IA

?

?

Thank you Jim for that bit of information. ,I replaced the transistor a few years ago working on it but just got around to working on it again.

Regards, Jim

On Fri, Jan 31, 2025 at 10:37?AM Jim WA9Z via <jim= [email protected]> wrote:

Our records show having replaced a few of these over the years.? BM and the buffer.? Almost sounds like it qualifies for common failure analysis. The 2n4427 has unique properties, not easily substituted.? ?

Jim WA9Z

Exline IA

?

?

Yes, can cap was already replaced before I got this radio. He didn't put a new can style in it, he used individual caps.

This tread is very long now. The original problem is solved with the baked Xtals. Should I start a new thread?
73, Dave KD5FX

Please publish your results.? ?They will be very helpful to the group

?

73

K1NR