Thanks for the information Paul, wish I could do the same as yout, but
my FL2100Z is the nine band version with three wafers for S7. The
problem is that the complete switch-assembly I got from the Yaesu
in Japan via their Swedish represantive has the same partnumber
as in the manual, but it's a lot different from the original one which I
stupidly removed without first checking the spare part... It does not
have the same number of contacts, have more, and when in position
it seems I have to change all connection wires, some are going to be
too short as I see it now. I wish there was a connection schematic for
the switch, even the old one had three wafers, in the manual it shows
only two. a ''major'' one and the S7B for getting in the padding caps
for 80 and 160 meters. It will take some time as I had to remove both
C1 and C2 in order to get the bandswitch accesable, but I'm sure I
will find out the wiring some day!
I'm sure, as you and Rich, that it was some VHF-parasitics, the tubes
are still OK but I also lost the mA-meter and the shunt. Got a new
meter but the shunt was not included, according to the parts list it
should have been.
I have checked your WEB-site, and our old bandswitches look about
the same...
100 USD for the switch-assembly, simpler as it was for the six
band version of the FL2100Z, was really expensive, I paid:
Complete 9-band bandswitch assembly S7 USD 52
Plate and SWR Meter USD 38
-- original parts in sealed boxes from Yaesu --
But here in Sweden we also have Value Added Tax, 25 percent,
so totally it became USD 112, cheaper than from California, hi.
One question Paul, I use Cetron 572B's, did you use Svetlana
when you had the parasistics?
I have bought a kit from Rich some years ago for an SB-200 and
it helped, at that time I had Svetlana tubes in that amplifier.
All the best to you Paul and to other readers of the Amps Reflector,
73 de Osten SM5DQC
sm5dqc@algonet.se
----- Original Message -----
From: "Paul B. Peters, VE7AVV" <ve7avv@shaw.ca>
To: "Amps Reflector" <amps@contesting.com>
Cc: <sm5dqc@algonet.se>
Sent: Saturday, November 30, 2002 8:01 PM
Subject: Re: FL2100Z bandswitch question
> Osten and friends.... almost one year ago, I too was facing a burned band
> switch in my FL2100Z amp and it was not a pretty sight! With help, I finally
> got the amp back on the air. In my particular case, I had bought the amp
> used and believed (based on the sellers comments) that it was working fine.
> That was my mistake -- but that's another story.
>
> I believe the band switch let go or burned because of a parasitic in the
> amp -- especially apparent on 15m. The oscillation was so bad, you could
> tune up on 15m and turn in and out of the point of parasitic oscillation --
> you should have heard it sizzle. Eventually -- and much to my surprise, the
> band switch gave in to its parasitic pain with a huge flash of white light,
> a corresponding big bang and the tell-tale smell of burnt electronic
> components. The damage done by the failed band switch was extensive! It
> included both tubes and a variety of other parts. This repair was to prove
> very expensive before all was said and done. I contacted YAESU in California
> to order the $100 USD switch and was told the it had been discontinued. I
> subsequently found all the replacement wafer parts in a friends huge junk
> box. The new tubes were sourced from
> http://www.vacuumtubes.net/page/indexc.html in Florida for about $40 USD
> each; they are Chinese tubes.
>
> The original band switch adds additional capacitance progressively as you
> switch to 80 and 160m. It is 100pF on 80 and 350pF on 160m. Given I couldn't
> duplicate that process on junk box wafer replacement, we hard-wired the
> correct capacitance directly for 80 and 160 respectively. Prior to
> disassembly, everything was tagged and labeled. With the original switch out
> and dissembled, the replacement (junk box) wafers were easy to add. With the
> band switch back in all wiring was reattached as per the labeling. For
> brevity in this story, I'll leave out the embarrassing part about my own
> stupidity in the overall process -- but suffice to say I learned a great
> deal about amplifiers through the overall repair process. Given this was my
> very first amp, I went into this repair knowing almost nothing and come out
> of the experience with a healthy respect for doing things right the first
> time.
>
> The one single addition made to the amp in the repair -- that ironically
> cost the least -- that I think is a must for this amp is a
> Parasitic-Suppressor Retrofit-Kit for the pair of 572B's. While there are a
> variety of opinions on the subject of parasitics, in my case it really
> works! My source was: http://www.vcnet.com/measures/.
>
> For a graphic explanation of the event, I've put together a series of images
> regarding the repair at: http://www.bcdxc.org/yaesu_fl2100z.htm.
>
>
> 73 de Paul, VE7AVV
> StoneyGround Station
> -|<*><*>||<*><*>||<*><*>||<*><*>||<*><*>||<*><*>||<*><*>||<*><*>|-
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>
>
>
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