Re: AVO CT 160 Improved Anode Current Measurement
Talking of additional metering to improve a CT160's accuracy, mA/V - wise, I've sometimes thought & mooted the prospect of fitting a wee meter to monitor the 55V T/F winding. After all, the whole caboodle of initially ensuring the "Set AC" locus before proceeding with all the tests - is to mainly make sure that RV2's source of working -ve half-waveform is spot-on. However, if one is involved with studying or tabulating Ia & Vg & taking several minutes to do so, then one cannot keep going back to "Set AC"(& in doing so - switch off the heater supply) to ensure that the incoming mains hasn't altered. That single transformer'd CT160, in my experience, is more susceptible to domestic mains supply changes. Lets face it - it was designed for field or ship usage by semi-skilled servicemen who followed the old adage - if in doubt - take it out, if the valve's mA/V indication failed to reach the Green zone.
These days, CT160's are a collectable item of vintage test equipment, for use in enthusiast's workshops. But in truth - they are just a 60 odd year old, expensive to repair, AC operating portable valve tester. Not really a workshop/laboratory VCM(Valve Characteristic Meter).
Regards, David
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