Making an Adaptor from the vintage single wire 5/8" screw on MIC connector to BNC

[t***@myshop.com]

Most of my vintage testers have those old style 5/8" screw on MIC
connectors. I have considered changing all of them to BNC and I see many
people do this, but I really dont feel like opening each tester to do
this, plus I kind of like keeping vintage gear original.

I have some probes with the MIC connectors, but there are times I'd like
to use a probe with a BNC on my vintage testers.

My idea is to simply make a few adaptors. I have several of the old MIC
connectors, and I have a bunch of the chassis mount BNC connectors
(which I believe is called the "female"). But I am not seeing any
INLINE female BNC connectors. If I could find these female INLINE ones,
I'd simply take a 6" piece of coax, and put the MIC connector on one end
and the BNC on the other. Making 2 or 3 of these should suffice.

Has anyone seen any female INLINE BNC connectors to buy?
Or, is there another method to accomplish this?

Yes, I could solder on the chassis type BNC connectors, but they would
lack shielding at the connector.

[Fox's Mercantile]

Post by t***@myshop.com
Has anyone seen any female INLINE BNC connectors to buy?
Or, is there another method to accomplish this?

You can use these:
<https://www.ebay.com/itm/183118810685>

Or you can do what I did.
1. Remove spring from connector.
2. Drill out connector back with 11/32" drill.
3. Tap connector shell using 3/8-32 tap.
4. Solder #16 wire to solder cup on back of BNC female.
5. Stick wire through connect grommet in Amphenol connector.
6. Screw BNC into connector shell. Tighten.
7. Solder wire to Amphenol connector grommet.
8. Cut wire, smooth with file.

Presto! Instant, sort of, Amphenol Microphone to BNC adapter.

[Dave M]

If you don't mind buying from Chinese sellers and waiting a month or so
for delivery, Ebay item 113114727770 is what you're after if you don't
have the tooling for a crimp style connector (Ebay # 323326819341).
Or, you could get several of these (Ebay # 392106541719) with the BNC
already assembled onto the cable, Just cut off the banana plugs and
solder your mic connectors onto the cable.

Cheers,
Dave M

Post by t***@myshop.com
Most of my vintage testers have those old style 5/8" screw on MIC
connectors. I have considered changing all of them to BNC and I see many
people do this, but I really dont feel like opening each tester to do
this, plus I kind of like keeping vintage gear original.
I have some probes with the MIC connectors, but there are times I'd like
to use a probe with a BNC on my vintage testers.
My idea is to simply make a few adaptors. I have several of the old MIC
connectors, and I have a bunch of the chassis mount BNC connectors
(which I believe is called the "female"). But I am not seeing any
INLINE female BNC connectors. If I could find these female INLINE ones,
I'd simply take a 6" piece of coax, and put the MIC connector on one end
and the BNC on the other. Making 2 or 3 of these should suffice.
Has anyone seen any female INLINE BNC connectors to buy?
Or, is there another method to accomplish this?
Yes, I could solder on the chassis type BNC connectors, but they would
lack shielding at the connector.

[Jim Mueller]

Post by t***@myshop.com
Most of my vintage testers have those old style 5/8" screw on MIC
connectors. I have considered changing all of them to BNC and I see many
people do this, but I really dont feel like opening each tester to do
this, plus I kind of like keeping vintage gear original.
I have some probes with the MIC connectors, but there are times I'd like
to use a probe with a BNC on my vintage testers.
My idea is to simply make a few adaptors. I have several of the old MIC
connectors, and I have a bunch of the chassis mount BNC connectors
(which I believe is called the "female"). But I am not seeing any
INLINE female BNC connectors. If I could find these female INLINE ones,
I'd simply take a 6" piece of coax, and put the MIC connector on one end
and the BNC on the other. Making 2 or 3 of these should suffice.
Has anyone seen any female INLINE BNC connectors to buy?
Or, is there another method to accomplish this?
Yes, I could solder on the chassis type BNC connectors, but they would
lack shielding at the connector.

You can remove the spring from the mic connector and drill the opening
out enough to remove the plating. Then take a single hole style BNC
connector and file the threads down until it fits in the mic connector.
Solder a wire onto the center of the BNC and feed it through the hole in
the mic connector. Then solder the BNC into the back of the mic
connector and solder the center contact. That's how I made mine. It
avoids having to come up with an unusual size tap.

[t***@myshop.com]

Post by Jim Mueller

Post by t***@myshop.com
Most of my vintage testers have those old style 5/8" screw on MIC
connectors. I have considered changing all of them to BNC and I see many
people do this, but I really dont feel like opening each tester to do
this, plus I kind of like keeping vintage gear original.
I have some probes with the MIC connectors, but there are times I'd like
to use a probe with a BNC on my vintage testers.
My idea is to simply make a few adaptors. I have several of the old MIC
connectors, and I have a bunch of the chassis mount BNC connectors
(which I believe is called the "female"). But I am not seeing any
INLINE female BNC connectors. If I could find these female INLINE ones,
I'd simply take a 6" piece of coax, and put the MIC connector on one end
and the BNC on the other. Making 2 or 3 of these should suffice.
Has anyone seen any female INLINE BNC connectors to buy?
Or, is there another method to accomplish this?
Yes, I could solder on the chassis type BNC connectors, but they would
lack shielding at the connector.

You can remove the spring from the mic connector and drill the opening
out enough to remove the plating. Then take a single hole style BNC
connector and file the threads down until it fits in the mic connector.
Solder a wire onto the center of the BNC and feed it through the hole in
the mic connector. Then solder the BNC into the back of the mic
connector and solder the center contact. That's how I made mine. It
avoids having to come up with an unusual size tap.

I was holding both parts in hand and thinking about doing something like
that, except my thought was to epoxy the BNC into the Mic connector. (of
course making sure they fit tight so there is a good connection on the
ground side).

There have been lots of great suggestions in this thread!

[Fox's Mercantile]

The Amphenol button connector is 3/8-27 pitch.

Is this about the connector depicted here <https://archive.org/details/Amphenol/page/n5>
at the top left of page M-6 ?

Yes.

5/8-27 Industry standard.

[Martin C.]

I have never seen such a connector, but have read that the shell thread
is the same as a a PL259.
Could a common PL259 to BNC adaptor be modified?

Martin(Stockport)

[Fox's Mercantile]

Post by Martin C.
I have never seen such a connector, but have read that the shell
thread is the same as a a PL259.
Could a common PL259 to BNC adaptor be modified?

They are NOT the same.
The common UHF connector is 5/8-24.
The Amphenol button connector is 5/8-27.