[frsimen]

Hello Peter,

With the valve removed, there will be no oscillation and the only current drawn will be a few tens of microamps by the meter. You will measure 108V near enough on both sides of the resistor. All seems normal in that area from what you are reporting.

The purpose of the OB2 is to regulate the supply to the VFO to a constant 108V despite variations in the HT feeding it. 265V is on the low side but the OB2 is working properly. That low HT will be more of a problem in the HW16, particularly when combined with the unusually low heater voltage.

I'm a little concerned that the 110V output of your transformer may be as low as 100V, and that does beg the question as to what its power rating has.

Trying to drop from 150V to 120V with a resistor is not a good idea. The current drawn by the transmitter varies a lot between key down and key up. The 120V will be all over the place as a result if you use a resistor. The resistor would also be dissipating a lot of power, which is wasteful.

I've attached a diagram showing the general idea of the voltage booster. This goes between the step down transformer and the HW16. It uses a 230V to 24V mains transformer, which is running on the 110V supply, not the mains supply. If you do try this approach, make sure that the final item is kept in an enclosure to ensure that you can't get a shock from it.

Note that the if the 24V winding is connected the wrong way around, it will reduce rather than increase the output voltage, so you will need to check that you have the connection in the correct sense.

The output voltage from this arrangement will be much steadier with varying current than the dropping resistor approach.

Paula