ECP Torpedo III [indexed in first post]

The current daughter boards that you sent out are the cascade to the ccs right? I'm just trying to keep all the mentioned mods straight in my head.

Is the new mod the new CCS you were talking about a while ago?

 

Well some how I screwed up both boards. Neither are measuring correctly. Anyone in the Bay Area wanna meet up to help me? After I've ordered more parts from mouser of course.

 

Sorry to hear Dr. Out of curiosity, what soldering station do you use?

 

How are they measuring? Can you post some closeup pics?

 

This one measures 0.72 mA


This one measures 0.27 mA

 

I'm using a Weller WESD51

 

First thing I'd do is be sure you have the correct version of LM334. If it is, take some braid and clean up the solder joints, and use some alcohol to clean any flux. If that doesn't work, replace the FETs as they are the most likely to be damaged by esd.

 

Yeah, I'll give that a shot. I broke the headers pulling the boards off. Can those be picked up off of Mouser as well?

 

Got my boards assembled, but when I tested them, they blew. At first they read over 100mA, then nothing.
Followed the diagram exactly and checked each board with two meters.

 

Well this is not very promising. Any chance you reversed the testing voltage or the meter or the lm334? I'll triple check my parts list and assembly to see if the mistake is here.

 

I tend to be a bit anal with such things, so I followed everything very carefully, so, no, the voltage wasn't reversed. The only thing I can come
up with is that I may have overheated the FET's, although I've done SMD work before without trouble. I guess I'll order some more and try again.

 

By headers, I meant pins. Can these just be picked up at Fry's or something?

 

Mouser's database seems to be down. I'll get you a part number when it is back up.

edit: though you can use bent resistor leads, too.

 

Cascode, but yes.

related

 

Hopefully we didn't get hold of a bad batch of JFET's.

 

pins are Mill-Max part # 800-10-064-20-001000

 

Bad JFETs could lead to too low current, but probably not too high. I think I'd look for a solder bridge across the resistor. Shorting it could cause your issue.

 

Thanks!

 

Are the Amperex 7062 tubes correctly rated for this amp or are they at the edge of drawing too much power? Going to grab some tubes but i have a bad habit of leaving amps on and i don't want to worry about damaging it.

 

Pardon me if this is an ignorant question, but is the battery polarity shown on post 235 correct? I just tried replacing the JFET on one of my
boards, and when I tested it, the current spiked to over 600mA, then magic smoke.