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3.5mm connector for SD24 sampling head...

Chuck Harris
 

Hi,

I have an SD24 sampling head that is otherwise ok, but has a
3.5mm connector that was banged into a wall by the previous
owner. The connector leading edge is peened over a little bit.

Finding a new connector seems unlikely.

Does anyone out there have a parts unit SD24 or 26 that has a
spare connector?

Thanks!

-Chuck Harris

Reginald Beardsley
 

How extensive is the damage? If it's just the thread, a fine triangular needle file will fix that.

If the side has been pushed in so it is no longer round, but not too badly damaged, it's a bit more complex, but still a fairly simple repair if you have access to a small lathe with which to make a plug expander to fit inside the connector.

I made one once to fix a friend's flute foot joint which was worn and allowed the foot to fall off. It took a couple of tries to make one that worked, but I'm not a machinist and had no experience. All I had to go on was the concept of a conical plug being pulled into a conical hole which then forced the outer cylinder to expand.

Would you post a close up photo to the files section?

Have Fun!
Reg

Chuck Harris
 

Hi Reg,

The flat cylinder of the nose (that comes just before the thread), has
been smashed almost flat on one side. The mating surfaces (inside of
the connector), appear to be ok, to my calibrated eye.

I have thought about making a little rotary tool that would roll around
the outside edge, and roll the smashed edge back to the proper shape,
as it is pretty soft metal, but I fear that I will spend more time than
the plugin is worth, and destroy the needed accuracy of the APC 3.5mm
connector.

It would seem better to find someone that has an electrically damaged
head that has a good connector, and work out a trade for the connector.

I, of course, have no idea what I will find when I try to replace the
connector. I don't have a clue how it is terminated on the circuit
board... probably the success of such a swap is highly improbable.

-Chuck Harris

Reginald Beardsley via Groups.Io wrote:

How extensive is the damage? If it's just the thread, a fine triangular needle file will fix that.

If the side has been pushed in so it is no longer round, but not too badly damaged, it's a bit more complex, but still a fairly simple repair if you have access to a small lathe with which to make a plug expander to fit inside the connector.

I made one once to fix a friend's flute foot joint which was worn and allowed the foot to fall off. It took a couple of tries to make one that worked, but I'm not a machinist and had no experience. All I had to go on was the concept of a conical plug being pulled into a conical hole which then forced the outer cylinder to expand.

Would you post a close up photo to the files section?

Have Fun!
Reg



Bruce Atwood
 

[cid:part1.E4A154FB.31B925D5@...]

On 9/16/2019 10:26 AM, Chuck Harris wrote:

Hi,

I have an SD24 sampling head that is otherwise ok, but has a
3.5mm connector that was banged into a wall by the previous
owner. The connector leading edge is peened over a little bit.

Finding a new connector seems unlikely.

Does anyone out there have a parts unit SD24 or 26 that has a
spare connector?

Thanks!

-Chuck Harris



.



--
Bruce Atwood PhD
Department of Astronomy
The Ohio State University
100 West 18th Ave., Room 4055
Columbus, OH 43210

Phone 614.314.0189
FAX 614.292.2928

bobh@joba.com
 

On 9/16/2019 7:26 AM, Chuck Harris wrote:
Hi,

I have an SD24 sampling head that is otherwise ok, but has a
3.5mm connector that was banged into a wall by the previous
owner. The connector leading edge is peened over a little bit.

Finding a new connector seems unlikely.

Does anyone out there have a parts unit SD24 or 26 that has a
spare connector?

Thanks!

-Chuck Harris

Chuck Harris
 

I am not seeing anything even similar.

It is not an SMA, but rather APC3.5.

-Chuck Harris

bobh@... wrote:

Looks like Amphenol may still make it:

https://www.amphenolrf.com/connectors/sma.html?mounting_feature=424

Bob.


On 9/16/2019 7:26 AM, Chuck Harris wrote:
Hi,

I have an SD24 sampling head that is otherwise ok, but has a
3.5mm connector that was banged into a wall by the previous
owner. The connector leading edge is peened over a little bit.

Finding a new connector seems unlikely.

Does anyone out there have a parts unit SD24 or 26 that has a
spare connector?

Thanks!

-Chuck Harris

Reginald Beardsley
 

That's the sort of thing an expander plug can fix. However, I'd expect to spend most of a day on such a project. But that's because I'm a novice machinist. Not too sure that replacing the connector would be any easier though.

BTW brass work hardens very quickly and attempting to anneal the connector in place might not work out well. Though if you were lucky it would just unsolder it. Once it work hardens, further cold working will crack the metal. So I'd approach attempting to repair the connector with the expectation that I might have to replace it. You would only get one try at reforming the metal.

I would like to get a non-working head to take apart and study. I just don't want to spend too much on one. Certainly not the $200+ some people ask on ebay for "parts only" heads.

Reg

Chuck Harris
 

If you have a hankering for SD24 porn, there is a complete
tear down, with high resolution pictures on the tekwiki.

I am familiar with working brass. I suspect that this could
be done, but I have no confidence that the connector will
be accurate afterwards. Annealing brass requires you to
heat it to dull red, and then immerse it in water...sort of
the opposite of what you do with steel. I am sure that the
teflon would be ruined.

The connector doesn't look like a solder type. It appears,
from the pictures, to be screwed into a solid block, and
perhaps makes spring contact with the circuit board.

-Chuck Harris

Reginald Beardsley via Groups.Io wrote:

That's the sort of thing an expander plug can fix. However, I'd expect to spend most of a day on such a project. But that's because I'm a novice machinist. Not too sure that replacing the connector would be any easier though.

BTW brass work hardens very quickly and attempting to anneal the connector in place might not work out well. Though if you were lucky it would just unsolder it. Once it work hardens, further cold working will crack the metal. So I'd approach attempting to repair the connector with the expectation that I might have to replace it. You would only get one try at reforming the metal.

I would like to get a non-working head to take apart and study. I just don't want to spend too much on one. Certainly not the $200+ some people ask on ebay for "parts only" heads.

Reg



Leo Bodnar
 

You have probably all taken the lid off the sampling gate hybrid.
Has anyne else taken their amplifier module apart?
There are quite a few interesting design solutions in there.
http://www.leobodnar.com/files/Tek-hybrid.jpg
Leo