Hello,

I have a Univox U65Rn from the mid-70s which I've managed to get working except for the reverb. 

http://vintageunivox.com/pics/schematics/u65rn.jpg

It looks like an appropriate signal gets is getting sent to the tank, and when I tap the springs I get spring noise out the other end. But, none of the signal being sent to the tank makes it out the other side.

It appears to be a genuine Accutronics tank with two ~3" springs in it, but I have been unable to find any replacement tanks that look like it. I was going to attach photos but can't figure out how to upload them? The input DCR is 166R, and the output is 700R. I would honestly prefer to replace the tank with a larger one, i.e. a 9" one, and based on the schematic it looks like a unit with relatively high input/output impedance, and grounded input/isolated output would be appropriate to try - maybe something like an 8FB2B1B? I'm not sure how close I really need the impedances to be.

Any suggestions on troubleshooting or tank replacement generally would be much appreciated!

~O