Post by brucen on Apr 17, 2024 16:48:25 GMT 12
I've recently built a valve tester, largely following this design: valveheaven.com/2015/03/an-inexpensive-easy-to-build-diy-valvetube-tester/m
I've largely followed the design principle, but used readily available digital meters (DCV and DC mA) from Ali Express. I also ended up with 2 transformers - one for the HT circuit and the other for heaters and the meter supplies. If I was to do it again, I'd use a larger case - its a bit congested inside and on the front panel. I'd also think about including the ability to test rectifiers - but that would mean quite a different power supply design. The picture is of a good valve, about -2V of grid bias and nearly 12mA of plate current.
I've largely followed the design principle, but used readily available digital meters (DCV and DC mA) from Ali Express. I also ended up with 2 transformers - one for the HT circuit and the other for heaters and the meter supplies. If I was to do it again, I'd use a larger case - its a bit congested inside and on the front panel. I'd also think about including the ability to test rectifiers - but that would mean quite a different power supply design. The picture is of a good valve, about -2V of grid bias and nearly 12mA of plate current.
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