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Need help working with or replacing a ferrite tube

Hacdrag

Member
One of my radios (AOR 8200 MK111) stopped getting reception because the inside side of the BNC antenna jack lost its solder joint (presumably a solder joint, but perhaps it was affixed in a different fashion) to the circuit board. The wire was encased in a ferrite tube before making the inside connection, presumably to avoid local oscillation problems. I removed the wire and tube from the solder joint, but there isn't enough exposed wire on the side that needs to get to the circuit board, and I am therefore unable to solder wire on that end.

Please see the attached showing the problem with the connection before I removed the wire, as well as the size (approximately 1/4 inch) of the tube. I can't figure out how to expose more wire on the problematic end. It's in far too tight for me to simply push the other in to expose more wire on the other size.

A few questions:

How can I work with this existing tube to get more wire out of the short end? If not, where the heck can I get a replacement that size? Any links would be appreciated. Also, if I were to bypass the ferrite tube and just solder a wire between the inside of the BNC antenna jack and the circuit board, would the radio be a total disaster?

Also, could I solder the long end of the wire to inside of the BNC jack and use Flex Shot Rubber Adhesive Sealant Caulk, or some kind of glue to affix the other side of the ferrite tube to the circuit board, as long as I properly line it up to have the center with the exposed wire touching the middle of the circle thing it is supposed to be affixed to?

I'm not sure how it was properly connected before, but there wasn't any solder residue at all on the board.

I am working in a tight space, but I can fit a solder tip inside the small opening I have to work with.

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Last edited:

augustinetez

Active Member
From AOR's bulletin page - http://www.aorja.com/support/bulletin_ar8000.html#bnc - see points before 9 (on the webpage) on disassembly to make it easier to work on:-

9) If the antenna wire link was broken, it can be replaced easily at this point.

The original one fitted is a solid wire link threaded through a very small bead (usually white in color, it is not an inductor!).

A simple piece of wire soldered in place will replace this or, better still, add a small piece of flexible wire to prevent any future breakage.

If you are careful, the small bead can be slid off the original wire and threaded onto the new link (it usually has a spot of glue holding it on) although this is trickier than it sounds (and is debatable if its omission makes any difference at all).
 

Hacdrag

Member
From AOR's bulletin page - http://www.aorja.com/support/bulletin_ar8000.html#bnc - see points before 9 (on the webpage) on disassembly to make it easier to work on:-
Appreciate the prompt reply and link. My radio is the 8200 model, and the bulletin is for the 8000 unit, but I'm hoping the part about not having to replace the bead holds true for my model. We will soon find out. :)

My favorite part about this passage:

(and is debatable if its omission makes any difference at all)

So, I'm going to just solder a wire between the two points and bypass the bead. Now, I'm thinking that maybe that bead just exists to make the circuit board connection easier for the factory setup.

I'm going to try this without further disassembling the unit.

I do think that the BNC socket is a little loose though, and perhaps my struggling to remove antennas multiple times is what broke the antenna link in the first place. However, I don't want to have to deal with all of the steps to get access to the socket, and if my plan works, I'll just be very careful handling that radio's antennas in the future.

1:00 A.M. local time now - I'm about to go to sleep and will tackle this tomorrow afternoon or evening, and hopefully reply with good news. :)
 
Last edited:

rjenkinsgb

Well-Known Member
Most Helpful Member
I think you will find its a long test point pin style insert, not a ferrite.
Just an insulator with a piece of wire bonded or pressed in to it.

It would allow them to pre-fit it to the PCB and leave the free end for later attachment to the antenna socket. I've seen them in other equipment.

I can't find that exact ones, but there are thousands of types & makers change overtime. These give the concept.

The info augustinetez posted re. the sometimes being white backs this up; just an insulator, used as it keeps the link wire in place during manufacture.

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Hacdrag

Member
Makes sense to me, as the bottom of the piece fits exactly in the circle on the circuit board where it was supposed to be affixed to, so looks to me like it was in place to help fit and secure the bottom wire.

I'll be doing the new soldering by the end of the day and look forward to sharing the good news. :)
 

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