Identifying s.e.x. C4S

[Jim R.]

I found a board this morning that I belive is the C4S board for the s.e.x.2.1. It has 5 wires coming out of it, is approx 2 inches square (give or take) and doesn't seem to have any TO-220 devices on it, but they may just be bent over.

Is, or could this be the C4S board for the s.e.x.2.1?

Thanks,

Jim

[fullheadofnothing]

Well a 2.1 should have TO-220 Q2, so it sounds unlikely. Really hard to say without a pic or any parts values.

[Jim R.]

Ok, after taking a second feel, yes, there are two TO-220 devices that were just bent over. I stood them up and they don't appear to have the pins stressed. The devices are on opposite sides of the board with the mounting flanges pointing in and towards each other. Also, one of the incoming wires is soldered on one side of the board and then there is a diagonal jumper under the board that goes to the opposite side.

If we need any more information than that it will have to wait until I can get somebody who understands electronics over here to read any writing on the circuit board and/or the rest of the parts.

Thanks,

Jim

[Paul Birkeland]

Are the 5 wires teflon coated or PVC?  (Easy to tell because the PVC is a lot thicker)  Are two pairs of them twisted together?

If you have two twisted pairs and PVC wire, you most likely have a SEX 2.1 C4S.

-PB

[fullheadofnothing]

2.1 c4s uses teflon wire.

[Jim R.]

Hmmm... I don't recall but I think there were maybe three wires twisted together and another single, but I could be completely wrong about that. It seemed to me that the wire was PVC, but I'll have to look at that more closely tomorrow. Gout is flaring again and there is no way I'm going back down to my workbench tonight -- maybe not even tomorrow.

Thanks guys for helping me out -- at this point I'm 99% sure this is the C4S for the 2.1.

Just as an aside, does this have to be mounted with a plastic standoff, or can I use an aluminum one?

Out of all the C4S and shunt reg boards I've had, I think the only one that I didn't sell and was built was the one for the s.e.x. 2.1.

Thanks again for your help, and if I can, I'll try to get the answers to the most recent questions for you tomorrow. I can also probably take a pic and send it to PB.

Have a great Memorial Day guys!

-- Jim

[Jim R.]

Hey folks,

So, I got the board again and indeed there is a twisted pair coming out of each side, which come from the board right near the TO-220 devices. Plus there is one other single wire that enters in one corner and is connected to the board at the diagonally opposite corner and which runs along the solder side of the board.

The wire definitely feels like teflon -- hard to compress between finger nails and slick -- definitely not PVC. Gauge appears to be fairly heavy too -- maybe 18 or 20, but it could just be thick insulation.

Very unlikely that I'll get pics today, but I think now I've given you enouggh information and by the questions you have asked and descriptions you have given, I'm 99.99 % sure this is the s.e.x. 2.1 C4S. There appears to be only a single mounting hole -- roughly in the center and closer to one edge than the other.

I still have the. question about being able to use a galuminum standoff as opposed to a plastic one.

Again, thanks for all your help,

Jim
t

[Jim R.]

Ok, I just took another feel as I was putting the board away in a safe place with all the other kit parts and noticed that one of the TO-220 devices is indeed fatigued so my guess is that the pins aren't going to last very long. Also, because I'm an engineer, it probably means that the other device will also fail prematurely.

Can somebody tell me what these parts are and can I get replacements from [email protected]?

Also, can somebody comment on whether I can/should use plastic or aluminum standoffs to mount this when the time comes?

Thanks,

Jim

[Natural Sound]

Hi Jim, the part number is MJE5731A. The kit should have come with a 4-40 nylon standoff. If you are unable to locate it perhaps Eileen can send a new one with your transistors.

[Jim R.]

Hi Tom,

Thank you! I'll go with the nylon standoff then.

Take care,

Jim

[Karl5150]

Jim,
The C4S board for the S.E.X.2.1 is rectangular and has 2 mounting holes centered on the long axis, although only one is used.
Karl

[Jim R.]

Hi Karl,

That could also describe the speedball board :-) I know what you're talking about though.

If I remember correctly the board mounts on the screw that holds the center terminal strip that sits just in front of the power transformer.

-- Jim