[Amps] Measuring PT-2500A High Voltage

[Victor Rosenthal 4X6GP]

Older carbon resistors are often found to be too high in value. The 
simplest answer is to get a HV probe for your DVM and calibrate the 
meter in the amplifier.

73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
http://www.qsl.net/k2vco/

On 28/12/2022 17:51, Steve London wrote:
> First, thanks for the suggestion/schematics for low voltage PTT. I have
> that working now.
> 
> Seems like the HV on my PT-2500A might be low. The meter shows only 2700
> volts in standby. But how do I know that is telling the truth ? The circuit
> is straightforward - A voltage divider consisting of 1 megaohm and 10K
> going between + and - on a filter cap. The 10K is a pot to calibrate the HV
> meter. Could be that the HV is okay, but the calibrate pot needs tweaking ?
> It's also interesting that the 1 megaohm is tapped off the first of 5
> filter capacitors. That makes the assumption that the voltage drop across
> each capacitor/bleeder resistor is equal.
> 
> To make some measurements, I am thinking of putting 12 volts on the
> transformer primary and see what the B+ looks like. Yes, there's still some
> pretty high voltages, but it seems a lot safer than trying to measure 3 KV
> directly. Any other suggestions ?
> 
> Anyone know what the secondary voltage of the HV transformer is supposed to
> be ?
> 
> Thanks and 73,
> Steve, N2IC
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