>
>The funny thing is that overloaded components sometimes last much longer
>than theory says. Look at the old SB 220: that tiny receiving type switch in
>the output circuitry!
The measured breakdown V in the SB-220 bandswitch is c. 5000V.
> Very very soft as compared to commercial switches.
>That very weak 80 meter coil!
It is #14 gauge copper with forced air cooling
>My ex amplifier ( the very first in Sweden
>buit by me in 1968 -69? ) has never failed and is still in use up there
>above the Arctic circle with its original 3-500Zs with graphite anodes.
>Amazing. I always said, that one has to forget whats inside the SB 220 and
>look at the performance instead.
Take a look inside and you will find forced air cooling on the tank and
the filament pins. This is good.
> A very fb buy at a used price only a little
>bit higher than a pair of new 3-500ZGs made in France ( same as the original
>tubes - the only difference is that little glass plate that lifts up the
>tube from the socket - less tendency for bad soldered pins to produce bad
>contact ).
''Bad solder'' results from the SB-220 cooling fan motor not turning
freely due to lack of lubrication. . Oiling the fan bearings every
couple of years will prevent this problem. . In older units without oil
holes, drill c. #55 oil holes above the motor shaft. Use a syringe for
oiling.
>
cheers, Hans
>----------
>>Från: "Steve Thompson" <rfamps@ic24.net>
>>Till: <amps@contesting.com>
>>Ämne: Re: [AMPS] " Kein Rauch ohne Feuer ...."
>>Datum: lör 24 jun 2000 07.17
>>
>
>>
>>
>>-----Original Message-----
>>From: N6BUU@aol.com <N6BUU@aol.com>
>>To: 2@vc.net <2@vc.net>; philk5pc@tyler.net <philk5pc@tyler.net>;
>>sm5ki@algonet.se <sm5ki@algonet.se>; n6er@yahoo.com <n6er@yahoo.com>;
>>amps@contesting.com <amps@contesting.com>
To: <amps@contesting.com>
>>Date: 23 June 2000 19:59
>>Subject: Re: [AMPS] " Kein Rauch ohne Feuer ...."
>>
>>
>>>
>>>In a message dated 06/23/2000 11:22:32 AM Pacific Daylight Time, 2@vc.net
>>>writes:
>>>
>>><<
>>> As long as the hv ps filter capacitors make it through the one-year
>>> warranty period, all is well.
>>>
>>> - Rich..., 805.386.3734, www.vcnet.com/measures.
>>> end
>>> >>
>>>ok rich i guess i asked for that one! i just expect "parts" to last
>>>somewhat longer, than the warrenty period.
>>> HANK
>>>
>>Treated reasonably they do this, nearly all the time. I'm sure we would have
>>heard about it here if any amp brand had a tendency to fry its PSU in less
>>than a few years. In truth, the reliability of raw components these days is
>>excellent.
>>
>>Is there any history that amps with 'insufficient' decoupling suffer early
>>failure purely as a result of use on the lower bands? Is there any evidence
>>that rf hurts electrolytic capacitors?
>>
>>Steve
>>
>>
>>--
>>FAQ on WWW: http://www.contesting.com/FAQ/amps
>>Submissions: amps@contesting.com
>>Administrative requests: amps-REQUEST@contesting.com
>>Problems: owner-amps@contesting.com
>>
>>
>
>--
>FAQ on WWW: http://www.contesting.com/FAQ/amps
>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
>
>
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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