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Nederlands Forum over Oude Radio's |
Re: zelfbouw antiek oa. PM2-DEP240-HL210
Geschreven door maurice op 28. Dec 2006 16:47:34:
In reactie op: Re: zelfbouw antiek oa. PM2-DEP240-HL210 geschreven door Ed van der Weele op 28. Dec 2006 02:27:01:
Wat meer info ontvangen via de mail.
Ik ga er mee aan de slag:
Hello MauriceThat looks like it’s a nice simple set to get going again.
The DEP240 valve is not right however as it is an output valve, although it will still work adequately.
The “P” means power output valve and the numbers mean 2 volt filament at 0.4amp. I believe it was made by Osram.
Use 120 or 150 volts HT
Often there were HT tappings on batteries so that the output valve could be set at 150 volts and other stages at less volts to increase battery life
The output valve should be biased to the maximum amount to reduce anode current to minimum to save battery power and the centre AF valve set to about half the maximum bias
The first valve can be set to the lowest bias voltage
All these can be adjusted by trial and error to maximise performance whilst reducing battery consumption.
Any standard 2 volt valve can be used for the AF amplifier. Again the choice is made to trade off performance and power consumption.
Best wishes
Allan