Palomar 300A (customers) recapped and on the bench + how to tune.
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- Опубликовано: 27 авг 2024
- Just going thru another Palomar 300A. This is a customers. I normally don't do others but since Palomar 300A's are fairly easy for me and I quite a few parts for them, I decided to take on this one. It was a good looking one except the power supply board on the deck was butchered. Someone had badly wired in radial caps instead of axial's and the 4 power supply diodes was a mess too. No big deal, I change the caps anyway, and 6A 1kv diodes are super cheap now, so I changed them too. Then I slowly variac'ed it up and watched my amps and all seemed well with no smoke. It keyed but had very little watts. I then tested the tubes with my little converted Palomar 90A 1 tube tube tester and the 4 outputs tested at 100% but the 2 driver tubes tested at 30%. Replaced the 2 driver tubes and the watts are good now. with a mud duck 4 watt radio, it keys 300 and swings to 350 average and 500 peak. Would do more with a better radio behind it. Did find the Preamp not working at all. Found the preamp switch itself was bad and replaced it. Now its ready to rock and roll. If ran right, should last a long time. Just don't overdrive amps and don't mistune or detune amps. Whether you tune for dead key or swing either is cool as long as you are tuning it for max watts. Never tune an amp down. Yes, I know what over-coupling is but I say to those people.......know your audience.