A6302/P6302 current clamp questions and parts.


Jared Cabot
 

Alrighty, I've uploaded some extra manuals and the document I drew up of the plug pinouts.

Linked below for future reference:

https://w140.com/tekwiki/wiki/A6302


Albert Otten
 

On Sat, Apr 3, 2021 at 08:26 PM, Jared Cabot wrote:


OMG, I am a happy panda!

I connected the wires as below and it works! Not bad for a $160 gamble on this
probe. :)
Congratulations Jared. Important quality aspect is lack of noise in the most sensitive DC ranges.
Well, being not that good in color distinction I asked my wife for assistance., I'm glad we didn't make mistakes!
Maybe also good to mention in your overview that the ground strip should make contact with the body.
IIRC my P6302 had no groundstrip (yet).

Albert


Jared Cabot
 

OMG, I am a happy panda!

I connected the wires as below and it works! Not bad for a $160 gamble on this probe. :)
Luckily my coax (The clear-ish wires) weren't broken so I didn't have to worry about those being reversed.
Also, my serial number is B071921 for the record.

A - Red/White
B - N/C
C - Orange/White
D - Black/White
E - White
F - Yellow/White
H - Brown/White
J - Gnd strip (For Coax from Pin 1 of CT, common with K)
K - Gnd strip (For Coax from Pin 7 of CT, common with J)
L - N/C
M - Coax from Pin 1 of CT
N - Coax from Pin 7 of CT


Thanks again Albert for the help and risking your probe's well-being for my sake. :)
I'll have to make a little diagram of the late version pinout and upload it to TekWiki.

Jared

On Sun, Apr 4, 2021 at 01:20 AM, Albert Otten wrote:


A red/white
B NC
C orange/white
D black/white
E white
F yellow/white
J gnd strip
K gnd strip
L NC
M, N both blank plastic


Jared Cabot
 

Wow, thanks for that! There's no way I would have got it correct.....

I saw your picture at TekWiki and mine matches there, so I'll rewire my Amphenol plug to match yours and see what happens.

Many much thanks! :)


Albert Otten
 

Nasty surprise Jared: in my A6302 S/N B76170 all colors are different! With magnifier glass I feel quite sure they are as follows:
A red/white
B NC
C orange/white
D black/white
E white
F yellow/white
J gnd strip
K gnd strip
L NC
M, N both blank plastic

The ground strip end gets located between body and the inserted boot part.
M and N wire type looks exactly the same. That's problematic since these also determine polarity.
It's easy to verify that the lock switch is wired between C and J.
You can see some colors arriving inside the probe in my picture "component" view at Tekwiki.

Albert


Albert Otten
 

On mine, the white and yellow wires are reversed according to the diagram on
Tekwiki, so I wasn't sure if there was any other changes.
Does this even matter with these two wires?
Jared
In my opinion yes, you reverse the polarity of the Hall voltage. The feedback to current to maintain zero flux in the core would reverse and would explode.
If it takes not too much force to dismantle my A6302 plug I'll give it a try.
Albert


Jared Cabot
 

On mine, the white and yellow wires are reversed according to the diagram on Tekwiki, so I wasn't sure if there was any other changes.
Does this even matter with these two wires?

Jared

On Sat, Apr 3, 2021 at 06:41 PM, Albert Otten wrote:


Probe <1> diagram in the Rev AUG 1981 version of the A6302 manual
(070-3905-01) still is the same as that for the P6302 at Tekwiki. I see no
reason why Tek would have changed colors with the introduction of the trimpot.
Albert


Albert Otten
 

Probe <1> diagram in the Rev AUG 1981 version of the A6302 manual (070-3905-01) still is the same as that for the P6302 at Tekwiki. I see no reason why Tek would have changed colors with the introduction of the trimpot.
Albert

On Sat, Apr 3, 2021 at 10:52 AM, Jared Cabot wrote:


Hmm, next issue is making sure I get the correct wire colours to the correct
pins in the Amphenol plug.
Some of mine were different to the pinout on the TekWiki site, so I'm not 100%
sure I have it correct. As it is now, the clamp doesn't degauss (the AM503B
won't perform degauss when the clamp is closed) and I'm not getting any signal
out either.

Does anyone have the pinout of the later model current clamp?


Jared Cabot
 

Hmm, next issue is making sure I get the correct wire colours to the correct pins in the Amphenol plug.
Some of mine were different to the pinout on the TekWiki site, so I'm not 100% sure I have it correct. As it is now, the clamp doesn't degauss (the AM503B won't perform degauss when the clamp is closed) and I'm not getting any signal out either.

Does anyone have the pinout of the later model current clamp?


Jared Cabot
 

Yeah, I think it's just a case of the rubber becoming a bit compressed and loosing pressure on the cable.
I just reassembled it with a few adjustments and fiddling and it is a lot tighter than it was before, so I think we're on the right track.

Thanks a bunch for all the help! :)


Albert Otten
 

(continued) I overlooked something. When assembled it's not the cable that is inside the thicker rubber part, but the somewhat wider crimped piece! Maybe you can use some tape or whatever to make it a closer fit.
Albert

On Fri, Apr 2, 2021 at 04:46 PM, Albert Otten wrote:


Encouraged by your picture I dismantled my P6302 plug. It's exactly the same
construction as your plug, except in mine there is no washer at the right side
(in your picture) of the strain relief collar. There is one at the left side.
I have to reconsider the my compression theory.There is considerable free
space around the cable within the thick rubber part. I can slide the metal
bush over that tick part up to the rubber collar without much effort. But it's
hardly possible to slide the long sleeve over the cable. I had to clamp the
cable in a vice and use 4 fingernails behind the collar!
There is nothing to keep the crimped piece fixed in place. It blocks against
the ridge inside the metal bus when you pull the cable out and it bends the
wires when you push in. With the bus screwed in I can see the crimped piece
jiggle together with the cable.
So I guess the only problem is that your cable has too much clearance in the
sleeve.

Albert

On Fri, Apr 2, 2021 at 02:18 PM, Jared Cabot wrote:


Here's a picture of my disassembled plug.
You can see a disk shaped collar piece crimped to the cable just to the left
of the pin assembly.
With the whole thing assembled, the cable can still rotate in the strain
relief boot and that collar can move, leading to flexing of the individual
wires and eventual breakage.
I'm wondering if there is a missing piece in there to clamp that collar, or
some other reason it seems loose.

https://i.imgur.com/Wl1E1vL.jpg


Albert Otten
 

Encouraged by your picture I dismantled my P6302 plug. It's exactly the same construction as your plug, except in mine there is no washer at the right side (in your picture) of the strain relief collar. There is one at the left side.
I have to reconsider the my compression theory.There is considerable free space around the cable within the thick rubber part. I can slide the metal bush over that tick part up to the rubber collar without much effort. But it's hardly possible to slide the long sleeve over the cable. I had to clamp the cable in a vice and use 4 fingernails behind the collar!
There is nothing to keep the crimped piece fixed in place. It blocks against the ridge inside the metal bus when you pull the cable out and it bends the wires when you push in. With the bus screwed in I can see the crimped piece jiggle together with the cable.
So I guess the only problem is that your cable has too much clearance in the sleeve.

Albert

On Fri, Apr 2, 2021 at 02:18 PM, Jared Cabot wrote:


Here's a picture of my disassembled plug.
You can see a disk shaped collar piece crimped to the cable just to the left
of the pin assembly.
With the whole thing assembled, the cable can still rotate in the strain
relief boot and that collar can move, leading to flexing of the individual
wires and eventual breakage.
I'm wondering if there is a missing piece in there to clamp that collar, or
some other reason it seems loose.

https://i.imgur.com/Wl1E1vL.jpg


Jared Cabot
 

Here's a picture of my disassembled plug.
You can see a disk shaped collar piece crimped to the cable just to the left of the pin assembly.
With the whole thing assembled, the cable can still rotate in the strain relief boot and that collar can move, leading to flexing of the individual wires and eventual breakage.
I'm wondering if there is a missing piece in there to clamp that collar, or some other reason it seems loose.

https://i.imgur.com/Wl1E1vL.jpg


Albert Otten
 

There hardly can be more inside. That metal collar piece is a bus. Its other end presses the plastic pin block in position. It's screwed into the body by means of the external 3 turn outer screw thread in the middle. The pins and wires are inside the bus.
It feels as if the sleeve can hardly slide over the cable, even when cap is removed. The mm space in my photo is because sleeve+cable came out together. Going on would destroy wiring. Anyway, I still think that rubber compressed by the end cap also secures the cable.
My A6302 has the shiny plug version.
When new considerable force is needed to insert or remove plastic pin block. To remove I use a length of thin wall metal pipe which falls just around the pins and slides through the plug body. For the test plug I mentioned I could also use this "tool" to insert the pin block because I could attach the BNC connector later on.

No doubt there are other members who can help you immediately.

Albert

On Thu, Apr 1, 2021 at 06:02 PM, Jared Cabot wrote:


Looks the same as mine except my plug is chrome plated. :)
That inner metal collar piece around the rubber boot will also unscrew
allowing you to withdraw the whole assembly (with a little push to the pins to
ease the pin assembly out).

So far it looks identical to the way my plug is, but I'm not sure about what's
supposed to be going on deeper inside. I won't ask you to go deeper unless you
are comfortable though. :)


Jared Cabot
 

Looks the same as mine except my plug is chrome plated. :)
That inner metal collar piece around the rubber boot will also unscrew allowing you to withdraw the whole assembly (with a little push to the pins to ease the pin assembly out).

So far it looks identical to the way my plug is, but I'm not sure about what's supposed to be going on deeper inside. I won't ask you to go deeper unless you are comfortable though. :)


Albert Otten
 

Here is another attempt. Tekwiki again. Picture of plug with cap removed and strain relief pulled out a few mm. I didn't take the risk to dismantle the plug any further. The thicker rubber cannot go further in then halfway the inner metal part with the flats. I think the rubber is long enough to get compressed when the cap is screwed on. It might be that the thicker rubber is not part of the sleeve itself, difficult to see.
I made a test plug with an original Amphenol 185-9 plug. There a short rubber bus goes in followed by a short metal bus. The metal bus gets pressed in by the cap and then compresses the rubber. (This is at least the way I thought it was intended.)

Albert

On Wed, Mar 31, 2021 at 08:57 PM, Albert Otten wrote:


Ah yes, I was too quick because I remembered that photo I took years ago. I
made the special test plug but that was without the strain relieve. I guess
the inner part of the official strain relieve gets compressed (to less inner
diameter) when the end ring is screwed inward.
Albert

On Wed, Mar 31, 2021 at 07:58 PM, Jared Cabot wrote:


Thanks for that but it's actually the big metal plug that attaches to the
AM503 module that I'm looking for photos of.

Jared.


Albert Otten
 

Ah yes, I was too quick because I remembered that photo I took years ago. I made the special test plug but that was without the strain relieve. I guess the inner part of the official strain relieve gets compressed (to less inner diameter) when the end ring is screwed inward.
Albert

On Wed, Mar 31, 2021 at 07:58 PM, Jared Cabot wrote:


Thanks for that but it's actually the big metal plug that attaches to the
AM503 module that I'm looking for photos of.

Jared.


Jared Cabot
 

Thanks for that but it's actually the big metal plug that attaches to the AM503 module that I'm looking for photos of.

Jared.


Albert Otten
 

I added a picture to Tekwiki. Might help.
Albert


Jared Cabot
 

I just picked up an A6302 current clamp in non-working condition and found many of the wires in the plug had broken off.
It was easy enough to solder the wires but it looks like the cable is loose in the strain relief boot and free to rotate etc which will lead to future breakage in short order.

Can someone with one of these current clamps open up the plug and take a photo or two so I can see how it is assembled and also so I can see if I have any missing bits etc?


Also, does anyone have a source on the ground clip, part number 020-0167-01 or an equivalent part that I can use?


Thanks!
Jared