Palomar 300A Black Face

[Sonar]

I replaced it.

View attachment 20251

I was lucky enough to have Mike recap mine before he disappeared. He did much more but I'd have to find the receipt in order to see all that was done. Ive been using it (as of late) with the FS 2340, unaplified d104, and demco modulator. If one's long winded which I occasionally am the 300a's (white face) chrome cover gets extremely hot. I've seen some pictures of one's with four brackets raising the cover about 4" above the topside (tube section) which I might do in the near future. Besides that it works great. With 2 DK and 15 pep I see 100 DK and 480 pep on my wm1 (after over coupling) with excellent audio reports. I'm not sure how others rate them but for me it's one of the better CB tube amps I've owned. And I've owned at least one of every brand of 11 meter tube amp at one time or another (built in the 70's-80's). I'd get another if it has already been refurbished. I hope you'll post a clip of it in action once you're done with the rebuild. 73. PS 357 thanks for all the help with the phantom. I never got back to it. My brother will be visiting around Easter. He'll be here for a week. He's been tinkering with CB equipment for many years and we'll pick up where I left off. Gonna try to get the coil spaced correctly for better capacitance. Then take it from there. Thanks again my friend.

 

[357]

I was lucky enough to have Mike recap mine before he disappeared.

disappeared?

 

[Sonar]

disappeared?

He's hasn't actually disappeared. The last correspondence I had with him (about 2 weeks ago) he told me people began sending him items in three's. He said people talked to him about one item then sent him three or more. I think he's swamped. I don't think Mike was prepared to do all the work that he's gotten. I'm sure there will come a time when he catches up with everything. I hope until that time comes he stops taking work. He's stopped making YouTube videos which is a good start. I guess he realized wasting time on videos is exactly that. Be good my friend 357. 73

 

[357]

https://www.ebay.com/itm/Drop-in-su...627022?hash=item1a41a735ce:g:qx0AAOSwa81aLKGW

 

[dozerman]

Thank you Nomad, very good info as always!

I'm gonna burn in the tubes for 24 hours then if I can get ahold of a tube tester, test them.
I tested the caps and resitors, all check spot on.
I cant really reform them without keying the amp cause of that relay so I'm kinda stuck there.

I still have the beads on the driver but I think I will take your advice and make some proper ones....should I do all 6?

This unit does have 300VAC on that relay, I dont dare key it yet.

I'm really in a pickle for cash, not sure if I'll play russian roulette or not.
View attachment 18517

I cleaned all the relays (2) I could and was suprised they were in very good condition.

I did a 650KM round trip to get this amp and I'm in it for 250CAD including fuel.


Guess I got some desicions to make.

That's exactly like mine, but have the white face. It's a strutter. I will say, after @nomadradio helped pinpoint this for me, replacing the coax in the amp is a good idea. I lost my drivers, high side, and couldn't figure out why. Nomad mentioned the coax gets really hot in that area, insulation melts and shorts itself. Mine was the coax from the switch to the coil by the driver tuner. Had broken connection. As a precaution, I replaced every piece in it. Does very well now. I replaced all my tubes with 6lf6's. with a cobra 1000 swinging 17 pep, the amp does 450 rms. Good luck with yours!

 

[Dave11meterdude]

Looks really nice! I know this is an old thread but I just got a Black face 300A as well its brand new. Someone robbed a few things from it but I'm bringing it back to life. Mine has no transformer so I'm going to make a Heathkit PS-2 my transformer

 

[Dave11meterdude]

Or maybe an Edcor perhaps? I have the doubler rectifier bridge so i need 300V. Suggestions anyone?

 

[357]

ebay

 

[nomadradio]

First have a look at the rectifier/filter circuit board under the deck at the center-rear of the chassis. Has the two largest filter caps visible mounted on it.

If it has a square black bock of epoxy with four legs to the rear of the big filter caps, this is a bridge rectifier. It was built for a transformer with about 560 Volts AC output on the HV winding.

If instead it has four axial-lead 1N5406-type rectifier diodes, it has a full-wave voltage doubler HV supply. Calls for a transformer with the HV winding rated for 280 Volts AC, more or less.

The six 6.3-Volt tube heaters are wired with pairs in series to take 12.6 Volts AC at about 6 Amps total. There is leeway here, to rewire the tube sockets all in parallel. But if you do, the current draw will now double and you could have voltage-drop issues with the wires feeding the heater circuit.

I have been tempted to 'recycle' a Palomar 350Z by removing the power transformer, putting it into a smaller enclosure and installing a cable/plug to fit a 300A.

At least this way the 350Z would be good for something.

73