TC Gauge: AC/DC heater

[AngeloGomes]

I was wondering if a TC gauge, which was designed to use an AC heater, can be operated by using a DC heater instead.

I have several DV-3M gauges but the meter I have is designed for a DV-6. The problem is the meter electronics supplies at most 90mA while the DV3 requires 120mA and the induced voltage by the TC is 4 mV when it should be at least 9mV.

[John Futter]

AC/DC doesn't matter
all that matters is heater power must be correct for the tube in use

[Richard Hull]

Yes, the tubes are designed to operate at a specific current. Get that right by whatever means and you are close to the designed operating point. The meters are also scaled for a specific tube ONLY. They are more or less totally non-linear on the face, especially at the lower end, but in general, over their entire scale face. The bell Jar had a wonderful article about how to make and calibrate your own TC gauge meter with most any of the popular TC gauge tubes.


http://www.belljar.net/tcgauge.htm


Richard Hull