how to measure reverb tank impedance (hot rod deluxe)

[georage]

How do you read impedance on a 4eb3c1b or any reverb tank? I have two of these tanks and neither work. The impedance is supposed to be 600 ohm input and 2250ohm output. So i measure resistance cross the rca jack from tip to sleeve. I get 60ohms input and 250ohms output on the first and 60ohms input and open circuit output on the other. Am i doing this Wrong?

[Tom Phillips]

How do you read impedance on a 4eb3c1b or any reverb tank? I have two of these tanks and neither work. The impedance is supposed to be 600 ohm input and 2250ohm output. So i measure resistance cross the rca jack from tip to sleeve. I get 60ohms input and 250ohms output on the first and 60ohms input and open circuit output on the other. Am i doing this Wrong?

You are not doing it "Wrong." However, taking a DC resistance reading is not the same as a more involved "Impedance" measurement.
The DC readings are still a good check and your reading show that the tank with an open circuit output has a problem.
The next thing to do is an inspection inside the bad tank to see if it's just a broken wire connecting the transducer to the jack. If so, you can fix it by reattaching the wire.

[Helmholtz]

According to Accutronics data an input DCR of 60R corresponds to an impedance of 600 Ohm.
Output DCR of 215 R means an impedance of 2250 Ohm.
DCR values are approximate and may vary.

So very roughly impedance values are 10 times the DCR with reverb drivers..

[The Dude]

There are several charts on the web that show approximate DCR values for given impedance tanks. Just Google, for instance, "reverb tank DCR vs impedance". There's one on this page.

https://www.studiosoundelectronics.c...erbdcchart.htm

[Helmholtz]

Or here: https://www.amplifiedparts.com/tech-...d-and-compared

[georage]

aw you guys rock! thanks for those resourses. The tank with the appropriate resistances is working now. I can tap the tank and control the echo with the reverb knob. There is no reverb for the guitar though. none at all. guess i will go think about that,

[The Dude]

First check would be tank wires. I always check tank DCR readings at the connector that goes into the amp. That way you are checking wires and tank at the same time. If you get infinite reading, then determine if it's tank or cables.

[georage]

woohoo its a bad rca jack to the tank input. I was about to check pin 1 (output to reverb tank) of the reverb ic when it started working for the first time and I was able to fiddle with it (technical term), then tested dcr on the tank cables. one bad jack. Thanks a bunch guys.