Help with rebuilding 700B db switch

[Cryptopal]

New member here, hello!
Recently paid $20 for a 700b. Not at all abused but a bit nicotine infused. Once on the bench I found that the 0 to -20db switch was missing.
Opening the unit someone had bagged the switch inside with what appears all the bits there. The 5 leads to it were clipped so I am sure no signal will pass without some sort of switch connected.
I'm looking for a replacement or someone who can reassemble the switch.
By the way what a discovery this forum is! Thanks to Joe at White Oak for the link!

 

[WOPL Sniffer]

So, it's not abused, it just has some parts missing? The round switches are impossible to find. There are many other ways to do a workaround for this issue (missing switch).

 

[WOPL Sniffer]

Post a pic with what they left behind.

 

[WOPL Sniffer]

where are you located?

 

[Cryptopal]

where are you located?

Indianapolis

 

[WOPL Sniffer]

Post a pic with what they left behind.

yeah

 

[Cryptopal]

So, it's not abused, it just has some parts missing? The round switches are impossible to find. There are many other ways to do a workaround for this issue (missing switch).




View attachment 88097

Do you know of a compatible part number or a similar switch that I can use?

 

[WOPL Sniffer]

as I asked, post a couple a pics of what they left you, I do have some parts.

 

[WOPL Sniffer]

I found NOS Switches............

GET EM WHILE THEY ARE AVAILABLE

Flatted Shaft

NOS 1972 Clarostat on/off switch, 3A 125v 1A 250v rating. MADE IN USA. | eBay

This is a nice power switch. It has a 1/4" round shaft.

www.ebay.com

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Back part of the switch where the wires hook up (I have about 10 NOS)

does not come with the shaft

------------------------------------------------------------------------------------------------------------------------------------

 

[Cryptopal]

I found NOS Switches............

GET EM WHILE THEY ARE AVAILABLE

Flatted Shaft

NOS 1972 Clarostat on/off switch, 3A 125v 1A 250v rating. MADE IN USA. | eBay

This is a nice power switch. It has a 1/4" round shaft.

www.ebay.com

--------------------------------------------------------------------------------------------------------------------

Back part of the switch where the wires hook up (I have about 10 NOS)

does not come with the shaft

------------------------------------------------------------------------------------------------------------------------------------

Wow thank you!

 

[Cryptopal]

as I asked, post a couple a pics of what they left you, I do have some parts.

 

[Cryptopal]

This is what I have. There were parts to another switch in the bag so I am clueless what fits.

 

[Cryptopal]

Wow thank you!

The switch listed on eBay is on off. The switch I have is an on / on - to switch a 20db cut.

 

[J!m]

I bet it is on-on if you want it to be. Four contacts on the back...

 

[Cryptopal]

The switch listed on eBay is on off. The switch I have is an on / on - to switch a 20db cut.

Just purchased the switch. I note there is a jumper soldered across 2 pins that will solve the issue.
Thank you!

 

[WOPL Sniffer]

Just purchased the switch. I note there is a jumper soldered across 2 pins that will solve the issue.
Thank you!

Yep, just solder in the jumper and 3 wires, if you look on the back of the switch, it tells you it's a Clarostat 20, see it on your switch? It looks like your switch is 1 complete switch although it's probably busted. I've rebuilt a shit load of these and put them in all the wopl 700B's I built.

 

[WOPL Sniffer]

The part number of the back portion of the switch is Clarostat-20 and the shaft portion has its own switch control number and it depends on how you want the switch to be configured, such as a built-in volume pot or push/pull on/off. Those front shaft portion numbers are Ad-A-Switch SWE--20-DPST for our application but there are hundreds of wire wound resistors for customizing your switch. Or, order a complete switch like we did. Usually the front shaft portion goes bad from the set screw being too loose or from "Torque Em Tommy" reefing on the knob or being 40 years old

 

[Cryptopal]

Once I get the switch installed I think I will use a variac and bring it up slow. I was told this one was in storage for a bit.

 

[willamsom]

Sounds like you got a good find with that 700b. If all the switch parts are there, it might be possible to reassemble it, but replacing it could be easier for long-term reliability. Glad you joined this community is super helpful!

 

[mlucitt]

As usual, Perry finds all the good NOS parts that have eluded mankind for years. This time he saved a few for us, (I ordered some). And he has the knowledge regarding P/N's, wiring instructions, rebuilding tips, and historical documentation.
No wonder his old Harley-Davidson still runs strong!