Broken Loading Switch

[ka4koe]

Don't know how I managed to break this switch while working in another part of the tx, other than blame my usual retinue of attendant vile demons; but the ceramic on the coarse loading switch on the Valiant broke cleanly on one side, about 1/3 of the way in but not quite to the axle. There is only one affected contact. The contact is the one that feeds RF to the back antenna connector. I think someone else may have used Super Glue or another adhesive, eg. JB Weld? Or, am I just purely out of luck?

Thanks.

P

[ka4koe]

Since the wafer disk is ceramic, l'm gonna try some suitable epoxy. I figured the repair would be similar to reattaching the handle to a coffee mug, as both materials are porous. What have I got to lose anyway? The disk is not under any stress.

[WQ9E]

I have used one of the super glue variants numerous times to repair ceramic wafers with success.  If you need to do any soldering work do so BEFORE you use super glue.  You won't care for the vapors released from cyanoacrylate products when heated.

[K9DXL]

I've had good luck with JB Weld, used it to put together a shaft coupling that snapped when I tried to get a knob off my DX-100.   Just remember that it's conductive, so don't accidentally bridge any contacts that shouldn't be joined.

[W3RSW]

Your on the lower RF voltage side of the PI net so epoxy glue is ok to try. I wouldn't think it would be as good a repair on the HV side though.

[Todd, KA1KAQ]

Be careful where you use JB Weld. The most common type has some level of metallic contact as I recall. Fine in mechanical situations, not so good in close electrical proximity like a wafer switch.

[Jim, W5JO]

Be careful where you use JB Weld. The most common type has some level of metallic contact as I recall.

The last time I looked the slow cure type did not have any metallic content.  Things may have changed but switches I repaired some years back were not affected.

[ka4koe]

Thanks for the advice. My common thought is "what next?"

[W3RSW]

Hang in there Phillip.

A.). Think of all the stuff your learning, both in general and about the rig.
B.). Your well on your way to becoming an honorary Cuban.
C.)  You have a pre-1958 rig with many body hammered and glued parts to prove it.!
D.). Can't find a better conversation starter when you finally, proudly get it working.

And above all, remember that, "what can go wrong will go wrong."

Much more fun to follow. 

[ka4koe]

Finally got time to take some photos. Bad weekend. Don't ask.

[ka4koe]

Let epoxy sit for two whole days. The repair to the ceramic wafer seems to be holding. However, plate current still pegging all bands. Suspect something in tank circuit or B+. Loading control has very little effect. Perhaps one of the bypass caps at the B+ choke went short or near short. Will resume deliberations later when I'm fresh.

P