Palomar 300a transformer

[nomadradio]

To me it's worth 50 bucks plus shipping. That's the price I would offer someone face-to-face if it came in the door with no transformer and no tubes.

73

 

[Fusionstate]

It's not so much an amplifier as a project in the making. The visible oxidation means there will be some work to clean things up so they make proper electrical contact where they touch. Rusty caps on the tubes don't mean it's doomed. Does mean you need to make sure critical connections inside are not oxidized.

The HV rectifier/filter circuit is a full-wave voltage doubler. Meant for a transformer voltage around 280. Upper limit is 300 Volts AC. And that's a hard upper limit.

As it happens I'm looking for a 300A that was built with this particular plug-in relay circuit board. I worked up prototypes of an outright replacement for that board, a "plug and pray" to replace 1978 relays that nobody sells anymore by chucking the entire circuit board. A replacement relay soldered into a pc board must have the pins line up with the holes in the board. The "R10-E3604" relay in this amplifier is made from unobtanium. Discontinued many decades ago. All catalog-stock relays that size and shape have the pcb pins in a totally different footprint.

I would say to remove the tubes and sell them separately. They're worth more than a "project" amplifier, most likely.

I have a guinea-pig 300A that uses the other relay design, doesn't have the plug-in pc board at all. Proving that the prototype boards will work has been waiting for one of these to come through the door as a repair job. But the 300A isn't as popular as it used to be, and every 300A we have seen all year is the "other" kind without the plug-in pc board.

Let me know if you're interested in unloading it, especially without the tubes. They'll bring more on fleabay than the amplifier with all six of them plugged into it.

I suspect that my board would sell on the open market, but only if I have test data and know that it's reliable. Still haven't even tried one of them in an amplifier.

73

To me it's worth 50 bucks plus shipping. That's the price I would offer someone face-to-face if it came in the door with no transformer and no tubes.

73

Hmmm. Since I'm not going to try to fix it- I don't believe it needs anything more than a recap to be sure. I did notice the PVC membrane on a capacitor between the antenna input and output seemed to be split, but no arcing observable; And I'm not about to repurpose the Peavey power transformer; As I've mentioned;

I have no way of knowing the condition of the output tubes. I'd go for dat. Just so it has a good home. The only conditions are: You have to let the forum know what the outcome of the project is, even if only ends up on a shelf. . . I've got loads of that; And. . . . If it's not as represented as in the post. . . . I'll refund the $50.

How's the money gonna work?

 

[nomadradio]

I can PayPal it to you. Just need the email addy that serves as your P-P member ID. A private message on this forum is called a "conversation". That would keep it private if you send it to me that way.

It will definitely get a writeup here.

73