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Cobra0020
Posted on Thursday, May 15, 2003 - 11:15 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

This is My Question somebody has a palomar 300a for sale for about 200 dollars. The tubes are about 80 percent. If you were me would you.
A. forget about it in get a New tube amp like a klv
B. Rewire the socketssp it can accpet svetlana Tubes
C. Don't Use Tube amp

Stricktly your oppinion.
Thanks cobra
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2600
Posted on Thursday, May 15, 2003 - 4:05 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Uhh, as far as "A" goes, a new amplifier will NOT have 25-year maintenance issues. Kinda like comparing a new car off the showroom floor to a 1977 Shelby Cobra. Sure, it was hot stuff back then, but it's not just the years, it's the miles, too. A "100,000-mile tuneup" that takes care of ALL the little details, like a half-dozen electrolytic capacitors, relays, melted coax, MISSING parasitic chokes (on the four final tubes) and grungy bandswitch contacts will cost at least $100, maybe more than twice that. If ALL the tubes are perfect, that's still not cheap.

B: Rewiring the sockets (on TOP of the tuneup) will present you with an odd problem: headroom. Those tubes are much too tall for the "low-profile" cabinet. You will have to do some metal work to "raise the roof" enough to prevent the tube caps from shorting or arcing to ground. Add another $150 or so for the socket rewire IF it's the oldest version with sockets mounted on a metal chassis deck. The much more common version uses printed circuit boards to hold the tube sockets. Much grief is involved in shoe-horning the 9-pin sockets into those twelve socket-pin holes in a circuit board. Anyone who quotes under $25 per socket for that is probably not serious, or reliable. This brings your total WITHOUT any tubes up into the $250 to $400 range. That brings me to:

C: Tubes? Transistors? An amplifier is just a tool. The more it does for what it costs, the better a tool it is. Transistor amps are often pushed past the published power limits for the RF power transistors they use. This reduces you margin of safety from bad coax jumpers, loose antenna elements, flaky radios, bad wattmeter sockets, etc. The "Cost Of Ownership" can be higher for a "hot-rod" solid-state than for a tube amp that is operated sensibly. A set of tubes that lasts two years of careful use is cheaper per year than a solid-state amp that blows up twice a year. It's not just "Watts per dollar" when you buy the thing, it's "Dollars per hundred keys" to keep it running, too. Tube amps are still competitive on both those counts. If they weren't, nobody would be offering them for sale. Everyone would just yawn and buy a solid-state instead.

73
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Cobra0020
Posted on Thursday, May 15, 2003 - 5:35 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Thanks For The Info 2600.

Cobra0020
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bullet
Posted on Friday, May 16, 2003 - 4:07 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

well theres always D.
buy a ham amplifier like a nice heathkit sb 200 or the yeasu 2100 either will give you great servise and would be a much nicer amp than those other amps mentioned. and you can find them every where for $200-$300.
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409
Posted on Friday, May 16, 2003 - 5:54 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

They didn't make a 1977 Shelby Cobra.....