Re: Taylor 65B Sig Generator: Dodgy Waveform
Meanwhile, if you get bored, or if postie is late ...
Brutal option follows!
You could just -
. lift pos end of C4 C5
. probe cathode of V1 6X5 with CRO, using resistive divider if necessary
. DVM cathode V1 to earth
. warm up 2 mins
. observe CRO to see full wave rectified AC with symmetrical humps.
If not, it is probably low emission of one half of V1, or crook pwr transf or crook wiring joint.
. power down, restore C4 C5
. warm up 2 mins
. short junction of R1 and mod transformer to earth momentarily, with your choice of 100R or (insulated) screwdriver.
. measure volts V1 cathode to earth, including resistance of 100R or screwdriver.
. do maths to get mA DC from V1.
. the DVM will read approx average DC volts
. compare with V1 spec sheet.
. expect 35 mA or so
If low current, V1 is suspect or crook wiring.
By the way, can you (hand on heart) confirm the power transf pri tap is set for your local mains voltage, and that valves have a measured 6.3 V on heaters please?
.
Last edited by Radio1950; 3rd Dec 2021 at 4:49 am.
Reason: I am in two minds as to whether to cut it all
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