I-177B Tube Tester Calibration

Although my I-177B tube tester seems to be working fine, I haven't gone through a full calibration. So here goes following the instruction I found here: http://tubesound.com/2009/09/07/signal-corp-i-177-tube-tester-calibration/

Category:

Howto & Style

Tags:

• tube
• tester
• I-177
• calibration

[jrmcferren]

I looked at the datasheet for the type 83. If you need a solid state replacement put Zener diodes in series with the rectifier diodes. You want the Zener diodes to be rated for about 14.4 volts drop each in combination with the .6 volts of the silicon diodes. An 83 only drops 15 volts each side.

[bandersentv]

@jrmcferren Thanks for the info!

[generalcleanup]

Thanks for your video on calibrating the I-177B. I am a little confused on using the shunt resistors. Do you connect the shunt resistors across the DMM (i.e. one side to positive and one to negative) leads and then run jumpers from those connections to the test socket pads?

[bandersentv]

@generalcleanup Yes, that's right. The idea is to simulate the loading a vintage VOM would put on the circuit under test.

[gberlucchi]

Hi Bob

Do you have a source to purchase tube extender sockets. I did a search and didn't find a supplier.

Thanks

Gary

[bandersentv]

@gberlucchi I got some from Playthings of the Past and some from ebay. They can get a little pricey :-(

[bandersentv]

@Knaeckebrotsaege Nope, I just haven't finished the ac probe yet. I've been hunting around for something to use as a tip.

[Knaeckebrotsaege]

did you forget about the part 2 of the HP 410C VTVM ?

been waiting for that for quite a while now =/

[bandersentv]

@chompo7 Hey Joe. I was wondering where you've been. Happy New Year to you too!

[bandersentv]

@caiserECEguy Thanks. The part I found the most confusing was checking the mutual conductance with 10mA. At first I tried using DC, but the meter readings didn't make any sense.

I got mine for testing old tubes so I can sell them too.