It seems that Hans knows how to keep an amp alive. My SB-220 lived for
years and years with no problems. Keem 'em cool is the secret to long
life for all parts.
73
Bob K4TAX
measures wrote:
>
> >
> >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
>
> --
> FAQ on WWW: http://www.contesting.com/FAQ/amps
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
--
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|