[Amps] Power output drop

[Mike Waters]

Thanks, Vic. Someone else (in a private e-mail) just suggested line
voltage. I do monitor the filament voltage, but I should monitor the 240
VAC and look at the HV meter, too. There is a "too-long" run of #12 from
the breaker panel to the amp, and if that wiring heats up, that might do it.

As for the pi-net caps, that's what I thought at first. I have padder caps
--some with a high negative temp coefficient--- on both C1 and C2 in the
pi-net output. However, re-tuning should compensate for that and bring it
back up to full power out (shouldn't it?), but it never does.

73, Mike
www.w0btu.com


On Tue, Sep 10, 2013 at 8:29 PM, Vic K2VCO <k2vco.vic at gmail.com> wrote:

> Does the line voltage droop when you transmit, causing a drop in filament
> voltage?
>
> Do you have ceramic capacitors in the tank circuit that heat up and detune
> the tank?
>
>
> On 9/10/2013 6:03 PM, Mike Waters wrote:
>
>> `
>> Anyone have an idea why the power output of my dual parallel 833C 160m amp
>> often drops 200+ watts after several seconds? Re-tuning does not bring it
>> back up to the initial output.
>>
>> Not that a drop from 1500 to 1300 watts is a big deal, but inquiring minds
>> want to know the reason. :-)
>>
>> Description:
>> www.w0btu.com/833C_linear_amplifier.html
>>
>> More photos:
>> w0btu.com/files/misc/833C_linear_amplifier/?C=M;O=D
>>
>>
> --
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco/
>