Re: HP6209B component location layout
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I think you will need to select R38, (~30k) section 5-45, it sets the meter zero by canceling the programming current that passes through the current sense resistor. R53,(3k) may need to be changed also.
Check here for a manual with schematic.
Hugh Gilbert
Hugh Gilbert
Correction to my previous post: meant to say MINIMUM OUTPUT VOLTAGE after adding the 47K resistor in series with R10 is about 160V, maximum output is still about 320V.
I am checking some voltages around the current meter circuit: the -3V shown on the schematic to be present at one side of R38/R53 measures only -2.29V. Same value at the cathode of CR8 in the bias supply where this voltage originates. Cathode of CR7 has +1.77V.
CR7 is a 1N4830 "stabistor" 2.4V @ 100mA. Guessing some sort of reference voltage or early zener diode. On the other hand CR8 is listed as 1N3828 and seems to be a regular silicon small signal diode. The way they are connected in series in the bias supply (for among others temperature stability) I would expect the -3V output to be the sum of the CR7 voltage, plus about 0.6-0.7V additional drop of CR8, so indeed about 3V. But in real life CR8 seems to have a drop of only 0.5V as measured, so do I have a bad CR7 that has gone low from the original 2.4V to only 1.77V?
The other bias supply voltages: +43V is at +37.5V, and the +16V is correct at +15.98V.
And at the reference regulator, the +6.2V (33) measures 6.43V, the +12.4V (37) measures 12.66V, and the -6.2V (31) measures -6.22V.
All voltage readings referenced to +S (same as positive/red output binding post with correct rear jumpers in place).
All other rear jumpers where also verified earlier to be in the standard configuration as shown on the schematic.
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