Yes. That is a great solution. I have a 5kVA unit with 10V taps
from -40V to +20V compared to the incoming mains. I use it on my
AL-1500 and HF-2500 amps.
I run them on 230V and they are very happy there.
73, Alek. VK6APK
On 5/02/2020 11:26 am, W2XJ wrote:
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autotransformer is the solution.?
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
--
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Clark Turner
480-695-2898
