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Junker 858 Madison

Toroids went faster than expected, so I tore into the clock. Motor works, teeth on the first gear are trashed. Emailed the guy that sells Intermatic gears, 'cause that's what his website said to do for this type of motor (WG6B9A). We'll see what he has to say about it.

Anyone know if the nylon screws for the audio amp chip are M3 sized? I've had to scavenge these in the past and while I can steal them out of the 138 XLR I've got here, I'd rather just have a bunch on hand.
Here's a video on where to find the gears. I've done this a few times. The only thing I had to do was to open up the hole just a little in the one gear so it would slide over the shaft. I bought the timers from eBay for about $8.00 each.
 
Here's a video on where to find the gears. I've done this a few times. The only thing I had to do was to open up the hole just a little in the one gear so it would slide over the shaft. I bought the timers from eBay for about $8.00 each.

Ordered a gear set from him this morning. He claims he's pretty quick with shipping, we'll see.
 
Looks like the clock gears will be in the mail come Monday.

Decided after cleaning up TR402 and TR403 and putting silpads behind them I might as well get the AM regulator, driver, and final as well. Glad I did.

The final was kind of nasty looking on the solder side, with the cruft from previous solder jobs thick enough that I couldn't see the separation between traces. Cleaned that up and found that chunks of the traces for the emitter and base were missing. The emitter was easy in that the lead was long enough to reach over to where it needed to go to make a connection. The base, not so much. There was a component lead poking through the board with no copper around it. Grabbed a little copper donut and used the final's base lead to hold it down and connect it to the rest of the trace like it used to be.

Finished removing the glue, I hope. Squeezed a few coils back together. Replaced the meter lights and unlike the last guy in here I insulated the connections, so the radio is less of a fire hazard than it used to be.

Opened the SWR/MOD meter to see how stuck it was. Movement seemed to turn pretty freely. Checked it with an ohmmeter, open circuit. Probably not a good thing. Guess I'll head over to Barkett's and order one.
 
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I think I figured out the clarifier. It looks like whoever did the clarifier mod originally had soldered a wire to the cathode of D44, a 9 Volt zener diode. That's the wire I found one end floating in the chassis. I pulled that wire under the board and soldered it to the positive side of C135, which is also connected to D44. Funny thing is, if the original guy had done this he would have found that the wire he used was the perfect length to pull through the retaining clips around the edge of the board and reach where it's now soldered. :X3:

Did 399's power relay mod, since I was in there. Thanks, JJ!

On a parts hold for at least a few days. Got bits coming for the clock, the dead meter, the two inductors that are missing, and the big cap in the power supply.

Oh, and a new soldering iron. Mine literally fell apart. Metal bits just slid right off the ceramic element and onto the workbench. It's somewhat inconvenient when that happens. Eh, what did expect for 10 bucks?
 
New meter showed up from Barkett's. They ship them in little cardboard boxes now to avoid them being crushed like the first set I ordered 9 or more years ago. Anyway, not quite an exact match, as the little plastic pegs that the SWR/MOD plate goes on are spaced differently. I just used the old front and the new back to work around that little problem. Couple of dabs of glue to hold the meter scale in place and it looks pretty good.

One other thing is that the new meter has an orange/red needle where the old one was white. Guess I'll just tell everybody it's because the modulation is so hot.
 
Box from Mouser finally showed up today. Installed big cap for power supply, did a modest upgrade to from 3300 to 4700 uFd. Replaced the two resistor bodge with a 5 Watt 220 Ohm unit. Installed the new L10 and L11 inductors and the new audio amp chip. Audio is working!

But now it only puts out a tiny AM signal and nothing on sideband. So I'm going to have to track that down since sideband was working so obviously I screwed up somewhere. But at least that tiny AM signal is being modulated. As in I can hear it on another radio.

Since LC asked, here's the part numbers I used for the inductors:

L10, 56 uH, Bourns part number RLB0193-563K
L11, 68 uH, Bourns part number RLB0913-683K

In my excitement I forgot to measure their DC resistance to see if they're anywhere close to 40 Ohms like the Sam's calls out. A quick interwebs check shows them to be about 150 Ohms, so only a little over three times the original value if Sam's got it right.
 
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