autotransformer is the solution.?
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On Feb 4, 2020, at 9:41 PM, cturnertuning <clark@...> wrote:
?
My voltage here is 256. Same problem.
Sent from my T-Mobile 4G LTE device
The biggest single issue in this country (Australia) with the
2100 amps and a lot of others, for that matter, is the filament
voltage. Due to our 240V to
250V mains, it is always high.
With the 2100 series amps, the filament voltage, at the tube
sockets is typically 6.8 to 6.9 Volts.
Luckily, there is enough room under the chassis to install some
series/parallel wirewound resistors, in the filament line, to
bring the voltage back to the nominal 6.3V.
I have done this to at least 20 Yaesu amps over the years and in
every single case, it has tamed them right down to become a good
little amplifier with very few problems.
You can do all the other mods that you see floating around the
net but I've never bothered. After the filament voltage has been
corrected, I've never had an amp come back to me with problems.
73, Alek. VK6APK
On 5/02/2020 12:44 am, cturnertuning
wrote:
I have a 2100B to use with the FT 101 station.? I take it to
the cabin and use it on all bands. Typically run it at 500 out.
Never had a single issue with it ever. Its possible it was
worked on at some point and upgraded. I understand early 2100
and 2100B had real problems like you describe Jim.?
These amps where abused for sure as almost nobody hooked up the
ALC and if you ran it with a 101 you then put 150 watts into
it.? With the ALC hooked up and set, it backs the drive down to
about 50 watts and has a clean output.? There is zero gain to
place the amp on 240volt. The transformer does not have dual
primary. It will just run the amp off one leg of the 240.
The Bias and Oscillation problems of early units is described
here:
C
On 2/4/2020 4:06 AM, Jim VE7RF wrote:
I? had a brand? new? FL-2100B? back? in 1976.? ?Worked? on? all?
bands...? for a while.??
Then? on? 10M,? it? flat? out? would? not? tune? properly on?
10M..into a flat? swr.?
The? xfmr? ran? very? hot.....even? when? on? standby? for an?
hr.? (240? vac? ?60 hz)?
Cooling? was? very? minimal,? so added a? extra? fan? on? top,?
sucking? hot? air out.
SWR? meter? was flaky.? SWR? would? increase as power? output?
increased....which? is? nonsense? of? course.
I? believe? the? 2100Z? has? 160M.?
Pulse? tune? the? amp? (like? with? 60? wpm? dots.....and? use?
a pep? meter)..should? get? aprx? 600 w? out.?
Local? buddy also? had? a new? 2100B.? ?I? tuned his,? and?
promptly arced? the? bandswitch. His? was a parasitic?
nightmare? from? day 1. Never? did? get? resolved.? ??
I? see? there? is a lot? of? mods? for? these? amps.? Beware,?
it? has? taps for?
100/200? vac..for? JA? use.
Whatever? u? do,? don't? buy? either? version.? I? was glad to?
get rid? of? mine.
Jim? ?VE7RF
--
Please let me quote you for your parts needs!
I offer a discount on Protunes with parts order!
Clark Turner
480-695-2898
