31-10-2016, 02:24 PM
(This post was last modified: 31-10-2016, 02:25 PM by Mike Watterson.)
(31-10-2016, 01:15 PM)ppppenguin Wrote: ... within limits, as neither traditional nor modern testers will explore the high power and high frequency aspects of a valve.
That's why I went for patch approach.
Though mostly for high power or RF you need to test the the part in the actual target circuit (Tektronix pointed out that for RF and special functions a valve tester is nearly worthless). High power at RF is a whole can of worms!
You need a special jig to measure inter-electrode capacitance anyway.
For Mixer/Oscillators and maybe RF/IF:
I thought of having B9A base with plug in RF in, Mixer out coil and Osc Feedback coil and three tuning caps. Then a calibrated RF / AF source (with attenuator), maybe my DDS generator, and calibrated RF/IF detector with attenuator. Adjust attenuators for same reading on meters and read off conversion gain.
The same jig would also do IF/RF amps. Probably usable from 40KHz to 40MHz.
VHF and UHF would need a pair of different dedicated jigs.
Different valve bases via adaptors.
HT via unswitched patch on uTracer (as the current is low, under 2mA) and uTracer LT supply.
