--- In ham_amplifiers@..., "g0vdz" <g0vdz@...> wrote:
Dear All, I have a Yaesu FL 2100z. I have had it for about 6 months
and all though I do not use it very much it is nice for contests.
I went onto cqww and decided to enter a topband entry. When i fired
up the liner, it would only put out a marginal signal. I.E. 25 watts
in 40 watts out.
I have lifted the lid and the RFC or anode choke looks a bit the
worst for wear. Could this be the cause of the problem. The other
bands seem reansonable. Has anyone had this problem and if so what
was
the problem
Many thanks to all Nigel G0VDZ
## I USED to own a FL-2100B new.. back in 1977. It did not have
160m in it. The xfmr ran hot, with just the fil + fan + hv on.
Turns out they all do. [xfmr was a combo plate xfmr + fil xfmr]
### what do u mean by other bands being reasonable ? You shoud be
able to get an easy 650 w out on all bands.
### sounds like the RFC went up in smoke.... or has shorted turns...
or is partially damaged. IF it works well on the other bands...
there still must be some continuity through it. Wish I had the
2100 Z schematic here. How big is the bypass cap at the base of
the plate choke ?? Would be interesting to know how many uh this
choke is... and whether it has gaps in it... or where they parked the
series resonances.
### How big is the plate tune and load cap ? Are either/both padded
on 160m ?? If either or is padded... via the bandswitch... u may
want to take a look at the bandswitch contacts.
### what is the INPUT swr on 160m ?? What is the INPUT swr on all
other bands ??
### careful with testing it with lids open... the HV interlock will
short out the B+.
## IF the other bands are good... I doubt it is a parasitic
problem... it's narrowed down to one band... 160m. IF the 160m
tuned input is good... and tune/load caps ok... it should work.
Still... if a 160m padder is not engaged... that would kill the power
output right there..... which should NOT imo... damage the plate
choke. The plate choke may just be discoloured.
## You are going to need to go through the schematic.... with
everything switched to 160m.... and trace out the 160m portion in
detail.
Later... Jim VE7RF
