# Muzzle



## Redredbettyz (Feb 9, 2019)

Anyone give this PCB a shot? I get no signal and the THAT 4301 gets very hot in a short amount of time. I've gone over the board for cold joints, or misplaced components a few times and everything looks good. Does it sound like I got a bad THAT IC? I hope not, that thing was not cheap.


----------



## Robert (Feb 9, 2019)

Yep this one has been built several times, I have one myself.

How did you wire up the these two spots on your PCB?


----------



## Redredbettyz (Feb 9, 2019)

I wired a spdt toggle switch to the three hole area. I left the two hole open. I assume the two hole is key input and the three is the range jumper?


----------



## Robert (Feb 9, 2019)

That's correct.    You'll need to temporarily install a jumper wire across the Key pads as well.  

This could explain why you aren't getting any output,  but the THAT shouldn't be getting hot regardless.

EDIT: Verified that the THAT doesn't get hot in normal operation


----------



## Redredbettyz (Feb 9, 2019)

Looks like it was a bad LT1054 causing the overheating. Things seem to be up and going in my test rig. Thanks for your help!


----------



## Robert (Feb 9, 2019)

Awesome!    This one is next in line for build docs....  Just in the event that you want to wire up the Key input.


----------



## geargasstore (Feb 9, 2019)

An LT1054 getting hot usually means you might have a short somewhere. Double check for any solder bridges. If you buy charge pumps from authorized places, you should(99.99999% of the time) never get faulty ones.


----------



## Redredbettyz (Feb 14, 2019)

geargasstore said:


> An LT1054 getting hot usually means you might have a short somewhere. Double check for any solder bridges. If you buy charge pumps from authorized places, you should(99.99999% of the time) never get faulty ones.


Can confirm on the bad LT1054, bad luck I guess. They have been my preferred charge pump because of lack of issues i've run into with them. I put a MAX1044 in there temporarily to check if I could get signal through, and it worked with some background noise issues (as expected). Got a new batch of of LT1054's in today and it fired up perfect. Thanks for your input!


----------



## Redredbettyz (Feb 14, 2019)

Robert said:


> Awesome!    This one is next in line for build docs....  Just in the event that you want to wire up the Key input.


Yes, I'm very interested in the key input feature. Does it involve using a TRS jack and wiring it to short when there is no 1/4" plug present? If so, I can probably figure it out before you get the build documents out.


----------



## Robert (Feb 14, 2019)

Yep, the two pads are connected by the switching jack when nothing is inserted.    

The pad on the left goes to the Tip lug, the pad on the right goes to the Switched Tip lug.


----------



## Dice1012 (Apr 2, 2019)

Robert said:


> Awesome!    This one is next in line for build docs....  Just in the event that you want to wire up the Key input.


Will the build doc's / wiring diagrams be posted soon?


----------

