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I let the power supply run for about 20 minutes with the fuse removed and it held steady at 13.8v so that's cool. Set radio to USB, keyed mic, no audio, TP4 showed about 68mA, VR15 brought it down to 40mA no problem. TP2 however shows a little over 3mA and adjusting VR16 hardly has an effect. Hmm.

All check fine. I also found my non conductive heat sink compound and got the final installed. This rig is back together and triple checked for solder blobs. I don't have a watt meter yet, would my rf volt probe tell what needs to be told at the antenna out? I'm assuming I'll need to check bias...

Roger that. I'll lift some legs and test this evening. Good stuff.

Hah, old final drops .006v base to collector, leads either way. Yep.

Sweet. Got the donor out, drops a little over .6v at both junctions and OL with leads reversed. I need to order some heat sink paste and umm a watt meter. Be a couple of days and I'll get these bits in and see where I'm at with this classic. Thanks you guys.

Hair dryer worked like a champ, slug swapped. On to C174 and TR43. I have no idea if the final in the donor radio is good but I'm going to pull it first. Would a simple transistor junction voltage drop check using the diode function on my meter be of any value before installing?

I wonder if it would be easier to swap the whole thing. I've got a good solder sucker and temp adjustable soldering station I used for the recap. The slug in the parts radio is still sealed, never been turned.

More info. I measured rf voltage through a few points in the driver and final stages on AM into dummy load. Referring to the schematic; location 150 reads .402v dead key going up to about .480v with auuuudio. 155 reads 14.8v dk up to 22.0v with audio. 158 reads 1.12v dk up to 1.35v with audio...

Ok it's transmitting, just weak. Rx into mobile sounds good up to about 1/2 mile out then quickly drops to no copy by about a mile and a half.

So, transmitting into a dummy load, the mobile in my jeep, about twenty feet away, is able to clearly hear the 458 on AM and sideband. It's weak, but very clear. I'm wondering if I should hook my vertical up to the 458 and take the Jeep for a ride. I think my wife would humor me for a few more...

Yesterday I was checking dc voltages as listed in Sams and so far everything checks out. I have a dummy load connected to the 458 and when I would key it up, the radio I was listening to dx on was picking up the signal, from about a foot away, so it's putting something out. My rf probe showed up...

Power supply is fixed. I checked all the voltages shown in the Sams schematic and found 6.16v instead of 15.06v at the base of TR302. I pulled and checked TR302, TR301, RT301, and R304. All checked fine. On a hunch, I lifted a leg of C410 and the capacitor check on my meter couldn't get a...

I do have an external power supply and several good working radios so that's not a problem. I'm going to build an rf probe for my multimeter, been wanting to for a while anyway, and when Sams CB#207 shows up I can do some probing and maybe get a better grip on this thing. I do want to get the...

Figured you meant RT301 and adjusting it made very little difference and actually the lowest voltage I see, right at 17v, is about dead center. Clockwise brings it up to maybe 17.5, counterclockwise never gets it below 17v. I went in small increments both ways after noting my starting point and...

I figured as much. Thanks! 8.14V When I initially went to take voltage readings, I had my negative test lead connected to the chassis but was getting way wrong voltages. I connected the negative lead to a known ground on the board and got accurate readings. Is the chassis not grounded? I also...

Thanks for that. TR24 on tx Collector 13.68v Base 9.08v Emitter 8.14v I also checked the voltage at my power supply and it's right at 17 volts. I feel like that's high and should be closer to 13.8?

I forgot to mention D28 and R112 got hot enough to start melting the insulation covering the long wire leads. I pulled R112 and it tested fine, haven't tested D28 yet. Also tantalum C188 got hot enough too scar C183 and L33 on either side. Hot enough to be an issue? Bonus points for the broken...

I ended up with two TRC-458s in a trade. One worked and the other had been hacked on pretty bad, probably be good for parts. Knowing they both have original caps, I rolled the dice and started using the one that works. A few days in I heard a bit of a hum and figured it was outside interference...

My first recap almost finished.

I personally don't care for linked GMRS repeaters. There is a large linked private network in my area and they've had up to three channels (channelized service so I'm calling them channels) monopolized at the same time on several occasions rendering all other local repeaters on the same channels...