PALOMAR 300A AND POWER SUPPLY SWAP

[Sonar]

I've use a 300a for my AM station. I'm the second owner. I have a acquaintance with 300a RF deck only. He unfortunately misplaced the power supply during a move many years ago. The amp for trade is the white Chrome Top Model just as mine is. Nomad did answer a post and explained that it would be devastating to use another power supply on a 300a if the power supply wasn't the compatible. There were a few differences between the Palomar 300 a RF decks (I think) I don't think it's the power supplies that are different but I could be wrong. I wish I didn't have to post this question because he explained in detail the easiest way to tell whether one 300a will work with a power supply from another 300 a. Can someone tell me what I need to look for under the hood of both 300a's that will tell me if it's the one that will match perfectly to my power supply? I tried looking for Nomads original reply to what I believe was my old Post about what I thought was the 300 a meter bulb on its last leg and how to or if I should bother to change it out. It turned out that it wasn't the bulb but the fuse located inside the power supply. The RF deck available is from an acquaintance and he actually doesn't want to sell it but wants to swap me for something that I hold dearly to my heart. I'd rather buy it from him but he's pressing me for the swap. The only way I'm going to agree to his terms is if I can definitively figure out if my 300a power supply will match perfectly to the 300a RF deck for swap. I know I'll need to compare my 300a with the cover off and the 300 a that is for swap. 73 PS I did try sending Nomad a pm. But I'm sure he's busy and couldn't get back This is my only option. This is mine. The one for swap is exactly the same exterior wise. I know that doesn't mean anything. I need to know what to look for in both of them to figure out if the one for swab will work with the power supply that operates my RF deck in the picture.

 

[Buddy 2020]

where can i find a 300a power supply

 

[nomadradio]

where can i find a 300a power supply

Which one?

There are two versions of the external power transformer. They both look exactly the same, and have no markings to distinguish which version you're looking at.

Naturally, the RF deck must be built for one or the other version of the transformer. A look at the circuit board dead center under the deck, the one with the two large filter caps is the only way to tell. If you mismatch them one way, the amplifier will perpetually be on "Low" side no matter which way the High/Low switch is set. The opposite mismatch will roach the high-voltage power supply and who knows what else.

A custom-made replacement would probably run 400 bucks in an enclosure with the fat cable and 8-pin Jones plug. It would be bigger. It would take two transformers, one for the high voltage the other for the low voltage. That won't fit in a box the original size.

Started to build a prototype of a 'universal' that would work with either type of RF deck, but paying work just keeps bumping it out of the queue.

Can't imagine we would sell all that many of them, and still charge enough to justify the labor it takes.

A metal box the right size is not in any way cheap, all by itself.

73