Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: benbendog on December 21, 2017, 10:48:58 AM

Title: Terminal 22 resistance
Post by: benbendog on December 21, 2017, 10:48:58 AM
 Hello All,

   I just started my CRACK build by painting the transfer cover and the case. After finished the part installation (no soldering yet), I review the instruction manual and I am really puzzled by how I could ever get 0ohm from terminal 22 to GND: the instruction basically tries everything it can to AVOID the long screw touch the chassis by inserting the nylon shoulder washer and fiber shoulder washer, I don't see anyway Terminal 22 can have a path to GND. Also if T22 has 0ohm resistance to GND, I would expect terminal 11, 16, 17 to do the same but they are not mentioned in the resistance check.
 
  Did I miss anything? I am an electrical engineer so I know the basics. :)

   Thanks for all the helps,
Title: Re: Terminal 22 resistance
Post by: Jay on December 21, 2017, 11:23:44 AM
I'm no engineer, but I think the manual instructs to do some soldering before doing the resistance checks.
Title: Re: Terminal 22 resistance
Post by: Doc B. on December 21, 2017, 12:51:10 PM
I initially posted the wrong answer, so here is the correct answer -

The transformer is grounded to the chassis safety ground via a wire. Terminal 22 is mounted on one of the transformer mounting screws, and, thus is also grounded to safety ground via the safety ground wire.
Title: Re: Terminal 22 resistance
Post by: benbendog on December 21, 2017, 03:05:20 PM
  Thanks for the answers.

   I think I figured out: in the soldering instruction we should ground terminal 16 to GND. T16 should connect other 3 long screws through the transfer cover so 16, 11, 17, 22 should all be connected to GND. I think it would be a little problem if we paint the transfer cover.
Title: Re: Terminal 22 resistance
Post by: Paul Birkeland on December 22, 2017, 04:18:02 AM
If you're not getting a good connection to ground there, you can try tightening the transformer mounting screws.  If that is the only transformer screw that isn't showing 0 Ohms, I wouldn't worry about it.