Folks,

Thanks for all this valuable info. I did check a few things more. Power
outlet is showing 124 Volts on my Fluke. When I turned the amplifier I
am not seeing any voltage changes on my outlet. I did take a visual look
to the 3-500Z. I am not familiar about this tube but when I do up side
down very gently I do hear a metallic click noise. It looks like some
thing inside the tube is loose. I did not load any RF to the amp yet. I
don't want to guesswork anything Ameritron manual says 3100V I have to
see it at least 3000V. 600V difference is big. Is any one see low
voltage on the soft or bad 3-500Z ???

Thanks to all for the help and 73s
Levent


Michael Melland wrote:
I'm not too familiar with that amp but... the specs on the Ameritron site
calls for 2700 volts with the AL80B under load and 3100 volts no load. 2400
is too low...... the HV shouldn't, I believe, change with a soft tube as
it's a measure of the transformer voltage. In my experience the main cause
of low plate voltage is low line voltage at the outlet.

The meter may be off some .... and 120 volts isn't exactly well regulated
voltage. Double check the tap set-up on the power transformer.... make sure
that is set for your line voltage. Measure your line voltage and set the
taps to the closest voltage...The info on the AL80B indicates it's a multi
voltage type transformer with 14 taps from 90 to 230 volts...but I'm not
sure about the AL80A.

DO NOT fool around inside an amplifier if you are not knowledgable about
working around high voltage and discharging capacitors. The HV in an
amplifier is LETHAL. (usual disclaimer grin)

Mike, W9WIS

Folks,

Thanks for all this valuable info. I did check a few things more. Power
outlet is showing 124 Volts on my Fluke. When I turned the amplifier I
am not seeing any voltage changes on my outlet. I did take a visual look
to the 3-500Z. I am not familiar about this tube but when I do up side
down very gently I do hear a metallic click noise. It looks like some
thing inside the tube is loose. I did not load any RF to the amp yet. I
don't want to guesswork anything Ameritron manual says 3100V I have to
see it at least 3000V. 600V difference is big. Is any one see low
voltage on the soft or bad 3-500Z ???

Thanks to all for the help and 73s
Levent


Michael Melland wrote:
I'm not too familiar with that amp but... the specs on the Ameritron site
calls for 2700 volts with the AL80B under load and 3100 volts no load. 2400
is too low...... the HV shouldn't, I believe, change with a soft tube as
it's a measure of the transformer voltage. In my experience the main cause
of low plate voltage is low line voltage at the outlet.

The meter may be off some .... and 120 volts isn't exactly well regulated
voltage. Double check the tap set-up on the power transformer.... make sure
that is set for your line voltage. Measure your line voltage and set the
taps to the closest voltage...The info on the AL80B indicates it's a multi
voltage type transformer with 14 taps from 90 to 230 volts...but I'm not
sure about the AL80A.

DO NOT fool around inside an amplifier if you are not knowledgable about
working around high voltage and discharging capacitors. The HV in an
amplifier is LETHAL. (usual disclaimer grin)

Mike, W9WIS

Folks,

Thanks for all this valuable info. I did check a few things more. Power
outlet is showing 124 Volts on my Fluke. When I turned the amplifier I
am not seeing any voltage changes on my outlet. I did take a visual look
to the 3-500Z. I am not familiar about this tube but when I do up side
down very gently I do hear a metallic click noise. It looks like some
thing inside the tube is loose. I did not load any RF to the amp yet. I
don't want to guesswork anything Ameritron manual says 3100V I have to
see it at least 3000V. 600V difference is big. Is any one see low
voltage on the soft or bad 3-500Z ???

Thanks to all for the help and 73s
Levent


Michael Melland wrote:
I'm not too familiar with that amp but... the specs on the Ameritron site
calls for 2700 volts with the AL80B under load and 3100 volts no load. 2400
is too low...... the HV shouldn't, I believe, change with a soft tube as
it's a measure of the transformer voltage. In my experience the main cause
of low plate voltage is low line voltage at the outlet.

The meter may be off some .... and 120 volts isn't exactly well regulated
voltage. Double check the tap set-up on the power transformer.... make sure
that is set for your line voltage. Measure your line voltage and set the
taps to the closest voltage...The info on the AL80B indicates it's a multi
voltage type transformer with 14 taps from 90 to 230 volts...but I'm not
sure about the AL80A.

DO NOT fool around inside an amplifier if you are not knowledgable about
working around high voltage and discharging capacitors. The HV in an
amplifier is LETHAL. (usual disclaimer grin)

Mike, W9WIS

"Levent Sasmazel" wrote in message
...
Folks,

Thanks for all this valuable info. I did check a few things more. Power
outlet is showing 124 Volts on my Fluke. When I turned the amplifier I
am not seeing any voltage changes on my outlet. I did take a visual look
to the 3-500Z. I am not familiar about this tube but when I do up side
down very gently I do hear a metallic click noise. It looks like some
thing inside the tube is loose. I did not load any RF to the amp yet. I
don't want to guesswork anything Ameritron manual says 3100V I have to
see it at least 3000V. 600V difference is big. Is any one see low
voltage on the soft or bad 3-500Z ???


If there is something wrong with the 3-500 to cause low plate voltage, the
plate will be glowing red with out any RF drive to it. This will indicate
high current and the tube is bad or the bias circuit is bad. If the tube is
soft or bad in any other way the plate voltage will be on the high side as
it is not drawing much current to load down the plate power supply. Too
low of a plate voltage indicates something is wrong in the power supply
(provided it is getting the correct primary supply ) or as was mentioned if
you are using the built in meter,something is wrong with it or the resistors
that determin the voltage range.

"Levent Sasmazel" wrote in message
...
Folks,

Thanks for all this valuable info. I did check a few things more. Power
outlet is showing 124 Volts on my Fluke. When I turned the amplifier I
am not seeing any voltage changes on my outlet. I did take a visual look
to the 3-500Z. I am not familiar about this tube but when I do up side
down very gently I do hear a metallic click noise. It looks like some
thing inside the tube is loose. I did not load any RF to the amp yet. I
don't want to guesswork anything Ameritron manual says 3100V I have to
see it at least 3000V. 600V difference is big. Is any one see low
voltage on the soft or bad 3-500Z ???


If there is something wrong with the 3-500 to cause low plate voltage, the
plate will be glowing red with out any RF drive to it. This will indicate
high current and the tube is bad or the bias circuit is bad. If the tube is
soft or bad in any other way the plate voltage will be on the high side as
it is not drawing much current to load down the plate power supply. Too
low of a plate voltage indicates something is wrong in the power supply
(provided it is getting the correct primary supply ) or as was mentioned if
you are using the built in meter,something is wrong with it or the resistors
that determin the voltage range.