B52 AT-100 Reverb Problem

[rf7]

This head has no guitar in the reverb output that you can hear. I pulled the tank, and all of the reverb springs were broken. Put a new tank in it and now I can hear the springs hit the side when I hit the tank, but I've got no guitar signal in it. I looked at the driver tube and it's getting a healthy signal, but the output looks very attenuated and clipped. I pulled the input leads of the reverb driver transformer and it only measures 148 ohms. The secondary of the driver transformer measures about 1.6 ohms, which matches the reverb tank input transformer measurement. The driver transformer has a very negligible and crummy output if at all. Is that reverb driver transformer toast? I tried a new 12AT7 and it did not make a difference. I should have measured the voltage on the plate of the driver stage--too late now, it's back together and the owner is picking it up tomorrow early. I'm not going back in there tonight.

It's a pain pulling the reverb tank in and out of this thing! Too many screws.

And now, if you'll excuse me, I have to memorize some songs from the first 2 Alice Cooper albums for a one off gig on Sunday night. Beefheart makes way more sense to me than this stuff.

[rf7]

My curiosity got the better of me and I checked the reverb driver tube and it is getting the correct voltages.

[52 Bill]

My curiosity got the better of me and I checked the reverb driver tube and it is getting the correct voltages.

Two things that come to mind are either a bad reverb driver transformer or the wrong input impedance tank.

[rf7]

OK, I did the RG Keen transformer test and it failed, but I have question about that.

I tried the test on a known good transformer and it passed, but only in one direction. When I fed the primary of a known good OT, the lamp flashes, but when I feed dc into the secondary, the lamp did not flash. Does the test only work in one direction? A known bad OT failed in both directions. The reverb driver transformer from the B-52 failed in both directions.