Feedthru replacements?? NLA from Moto..

kb0nly · Post by **kb0nly** » Wed Mar 15, 2006 12:43 am

I need a couple of the feedthru caps they use in the X9K to repair one that has some broken ones. I tried to desolder the broken ones, yeah right, they must have used the fires of hell to solder them in there...

Anyway i just broke them the rest of the way and cleaned em out of the holes but now i need replacements. They were one of the following part numbers... I think anyway.

2182812H03

or

2182812H07

They all come up as different values and all of them are NLA. The biggest problem is i don't know the value of the offending part, and there seems to be many values available on these. The one i need is used to power the optional preamp in the filter casting. I can't find it in the schematics and it just shows the preamp being powered by 9.6v line to it without a cap, but the radio does have one there..

Suitable replacements that would work?? Suggestions?

kcbooboo · Post by **kcbooboo** » Wed Mar 15, 2006 1:45 am

The value probably is not important. Get anything that will fit into the same space. I've seen ones that solder in, or that have threaded bodies. Usually the threaded ones are larger diameter.

They might have used some high-temp silver solder to hold the feedthru cap to the chassis, or if the chassis is aluminum, something else. If it's easy to get to, drill the hole large enough to accept another feedthru.

Find some other radio on the same band and see if the schematic shows a value for the feedthru cap. Since the schematic you have for your radio doesn't show any cap there, it might have been added to reduce other emissions and get the radio type-accepted.

It might be hard to buy just one feedthru cap. Surplus houses would be the best place to grab some, as would somewhere like Dayton !

Bob M.

kb0nly · Post by **kb0nly** » Wed Mar 15, 2006 8:08 am

Well, if the value is not that important i will browse through Mouser and Digi-Key and see what they carry. I checked both the VHF and UHF service manual, they don't detail the power connection to the preamp in that casting, but there is a feedthrough cap on both bands to supply power to it. The feedthrough cap looks the exact same as the ones used to feed the final PA section in there also, and chances are they probably used the same ones to save money.

I will check the value on those again, but i recall correctly they were listed as 1000pf or something like that.

kb0nly · Post by **kb0nly** » Wed Mar 15, 2006 8:10 am

Here is what MOL shows for the H03 part number..

CAP CER FEEDTHRU 1000 +100-0

kcbooboo · Post by **kcbooboo** » Wed Mar 15, 2006 8:58 am

Sure looks like a 1000pf (0.001uF) cap to me ! Find one that's physically the same and go with it.

I was thinking it had to be 1000pf or 10000pf but wasn't sure which one.

Try some surplus places, and even Ramsey and Hamtronics, as they might have a few they could sell you, if they're the same physically.

Bob M.

kb0nly · Post by **kb0nly** » Wed Mar 15, 2006 10:02 am

Well that's a good starting point! Know i know what i should need, 1000pf feed thru cap. The spot is easy to get to by just removing the entire casting, so minor size differences can be fixed quickly by drilling or using a reamer to tweak the hole a bit. It's soft metal, i think cast aluminum.

I do recall Hamtronics selling the feed thru caps on their parts page, and i will check Ramsey too since they used to have a lot of the small parts in their catalog.

kb0nly · Post by **kb0nly** » Wed Mar 15, 2006 10:43 am

Surplus Sales of Nebraska, surplussales.com has a good selection of both threaded and solder types. Looks like it's time to order.