I'd like to wire up a couple of HV diodes with series dropping resistors to replace a burned out RCA 83 in a Hickok 750. Has anyone out there tried it yet? What value of resistors should I use? Use capacitors across the diodes to simulate the plate-cathode capacitance?
Thanks for any help before I buy something similar!
ron...

:I'd like to wire up a couple of HV diodes with series dropping resistors to replace a burned out RCA 83 in a Hickok 750. Has anyone out there tried it yet? What value of resistors should I use? Use capacitors across the diodes to simulate the plate-cathode capacitance?
:Thanks for any help before I buy something similar!
:ron...

The type 83 was typically used up to about 500 V. per plate, so you could use a 1N4007 diode as a replacement. (Two diodes for a full-wave CT circuit.) The resistance of the 83 was about 60 ohms, so you might want to put a 50 or 60 ohm resistor in series with the diode to limit surge and to yield about the same output voltage as the tube. Make sure the resistor has adequate power dissipation capability! I wouldn't bother with any additional caps. If you really want to be conservative, use 2 units of 1N4007 in series for each half of the equivalent tube. Connect a 100K resistor across each diode to force them to share voltage equally.

Rich

::I'd like to wire up a couple of HV diodes with series dropping resistors to replace a burned out RCA 83 in a Hickok 750. Has anyone out there tried it yet? What value of resistors should I use? Use capacitors across the diodes to simulate the plate-cathode capacitance?
::Thanks for any help before I buy something similar!
::ron...
:
:The type 83 was typically used up to about 500 V. per plate, so you could use a 1N4007 diode as a replacement. (Two diodes for a full-wave CT circuit.) The resistance of the 83 was about 60 ohms, so you might want to put a 50 or 60 ohm resistor in series with the diode to limit surge and to yield about the same output voltage as the tube. Make sure the resistor has adequate power dissipation capability! I wouldn't bother with any additional caps. If you really want to be conservative, use 2 units of 1N4007 in series for each half of the equivalent tube. Connect a 100K resistor across each diode to force them to share voltage equally.
:
:Rich
:

Pair of 1N4007 diodes and a pair of 10-ohm, 5-watt resistors in series mounted to the 4-pin base of the 83 does nicely. And it does not throw off the calibration of the unit either.

:::I'd like to wire up a couple of HV diodes with series dropping resistors to replace a burned out RCA 83 in a Hickok 750. Has anyone out there tried it yet? What value of resistors should I use? Use capacitors across the diodes to simulate the plate-cathode capacitance?
:::Thanks for any help before I buy something similar!
:::ron...
::
::The type 83 was typically used up to about 500 V. per plate, so you could use a 1N4007 diode as a replacement. (Two diodes for a full-wave CT circuit.) The resistance of the 83 was about 60 ohms, so you might want to put a 50 or 60 ohm resistor in series with the diode to limit surge and to yield about the same output voltage as the tube. Make sure the resistor has adequate power dissipation capability! I wouldn't bother with any additional caps. If you really want to be conservative, use 2 units of 1N4007 in series for each half of the equivalent tube. Connect a 100K resistor across each diode to force them to share voltage equally.
::
::Rich
::
:
:Pair of 1N4007 diodes and a pair of 10-ohm, 5-watt resistors in series mounted to the 4-pin base of the 83 does nicely. And it does not throw off the calibration of the unit either.

::::I'd like to wire up a couple of HV diodes with series dropping resistors to replace a burned out RCA 83 in a Hickok 750. Has anyone out there tried it yet? What value of resistors should I use? Use capacitors across the diodes to simulate the plate-cathode capacitance?
::::Thanks for any help before I buy something similar!
::::ron...
:::
:::The type 83 was typically used up to about 500 V. per plate, so you could use a 1N4007 diode as a replacement. (Two diodes for a full-wave CT circuit.) The resistance of the 83 was about 60 ohms, so you might want to put a 50 or 60 ohm resistor in series with the diode to limit surge and to yield about the same output voltage as the tube. Make sure the resistor has adequate power dissipation capability! I wouldn't bother with any additional caps. If you really want to be conservative, use 2 units of 1N4007 in series for each half of the equivalent tube. Connect a 100K resistor across each diode to force them to share voltage equally.
:::
:::Rich
:::
::
::Pair of 1N4007 diodes and a pair of 10-ohm, 5-watt resistors in series mounted to the 4-pin base of the 83 does nicely. And it does not throw off the calibration of the unit either.
::::
:::: Thanks for the info! I'll give it a try. It seems much better than dealing with buying tubes on eBay & also with Mercury issues. I'll try to remove the burned out 83 tube base & put the circuit into that base. Any hints on how to get the base safely loose from the 83 tube?
ron...

The solid state conversion will work, but the readings for some tubes will change. It will still show good or bad tubes but don't expect it to match the readings of another 750.