Sounds like good troubleshooting technique to me. Maybe you can
evaluate
the
tube further to isolate what is wrong with it.
Charlie
Ham Radio - AD5TH
www.ad5th.com
Live Blues Music
www.492acousticblues.com
----- Original Message -----
From: "Dan" <dpipes@earthlink.net>
To: <Amps@contesting.com>
Sent: Monday, January 03, 2005 11:05 AM
Subject: Re[2]: [Amps] ok ONE more time <g> Ameritron 811H
well thanks to everyone's help I think I have it fixed.. well not
fixed
but
at least found the problem. I replaced the 51 ohm resistor a second
time.
this time at the advice of a local buddy he said pull that tube that
that
resistor is tied to and try again. well pull the tube turned the amp
on
and
all powers up without the excieing bang/pop.. and flash <g>
I did not try to load withonly 3 tubes but seems that proves the
problem
is
with the tube.. I have ordered a set as stated earlier and will have 3
extras i guess ..
any comments about this "test"..
thanks
*********** REPLY SEPARATOR ***********
On 01/03/2005 at 7:36 AM carl seyersdahl wrote:
The grid resistors are shown in my 811H manual as R 19 thru R22.they
are
listed as 51 ohms, 2 watt metal oxide.
I have always replaced these with 33 ohms 1/2 watt , and I've never
had
any problems, but then I've always replaced the parasitic
suppressors with
Mr. Measure's
Nichrome (not microbe) types. Never had any more trouble that I know
of.!!!!!
carl / kz5ca
----- Original Message -----
From: "Dan" <dpipes@earthlink.net>
To: <Amps@contesting.com>
Sent: Sunday, January 02, 2005 6:16 PM
Subject: [Amps] ok ONE more time <g> Ameritron 811H
You guys have had the answer everytime so far. I bought a 2nd hand
Ameritron
811H amp. It has worked very well exept .. at first start up serveral
weeks
ago.. after it had been stored when i first turned it on it arec at
the
vents 9right side) switched it off.. long story short after a few
turn ons
and off it work great.. I get good ooutpit and great reports. Well
over
the
past few weeks once in a while (only when I turn it on) I woud get
an arc
same place. after it has been on and after serveral times on and off
during
the day it would be fine great output and no arc even when switched
back
on
.. seemed like only would do it after it had been off all night and
then
only sometimes.. I have remoed and check for any signs of arc etc
never
found anythign..
Well until today.. I switched it on.. and again a little arc that was
visable at the vents.. and quickly this time a loud pop.
Well obviously not a good thing. I remove the cover again and this
time
found that one of the 53 ohm 2 watt resistors had actuall blew apart.
onone
end. I shoudl mention that this time I had very little power out
after the
arc/bang..
In reviewing the circuit I can ot tell what these four resistors are
but I
assume it has to do with some type of bleeder circuit to grd as all
four
have one log to grd the other to a small wire maybe 18 ga. (light
wires..
one is yellow one is blue and the other two are red..
the yellow one is the one that blew the resistor...
The diagram they provide in the book and the parts list has to be
incomplete
as the 53 ohn resitors are nto even liosted. there are two
physically near
the rear of the tube cage (just to the rear to the torrid) the other
two
are
near the front edge of the same are... the yellow wired resistor
that blew
is one of the two at the rear side of the tube cage..
Any ideas? Are these bleeder circuits ? part of the neutralization
circuit?
.. Any ideas what might of caused this .. this amp sat for about 3
yrs in
a
closet not used.. before I got it..
any ideas woud be of help. Could a tube of caused it? what else
shoudl I
check thanks
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