Bad cable to Primary Display - tight cable gland

Larre Ländin

Hello again,

I finally fixed the problem with my secondary (see different thread) and my unit is diveable again. Allthough since we are expecting our 2nd child any day now my hobby is limited to going through all my dive gear in the garage so that it is in good shape by the end of summer.

I have had a small problem that has been getting worse every dive. My primary display has a bad connection in the cable. At first it wasn't that bad, in some positions the lights flickered on the display. Now the problem has escalated so that the lights only show if I bend the cable slightly.

Today I dissasembled the display in order to shorten the cable a little bit and at the same time replace the lightbulbs with hi intensity LEDs. The problem is that one part of the gland holding the cable is to tight, I can't slide it further down the cable (see attached image).

Is there anyone who has done this before and who can give me any tips?

Maybe it would be possible to cut the cable and buy a new gland in the same size. If i can find the same part (marked in red in the image) brand new maybe it would be a little bigger since it hasn't been compressed. Part of the gland is a Swagelock but I have no part number.

Best regards, Larre

rdmmdr

larre

it looks like tthey used a brass compression sleve on the gland. it will have to be replaced as it is a one shot unit. swagelok over there should be able to provide the part. it is probably a 3/8 inch tube fitting. you can also get these in nylon but they don't list them on the web you have to ask for them.if you have problems getting one pm me and i will send you a couple of spares. check the dia of the cable or tell me what wrench you used to disamble i can tell the size that way.

rick m

heyydude

Larre,

It's a Swagelok B-600 Front and Back Ferrule set. I believe the Swagelok part number is B-600 SET, but I'm not in the shop right now, so I can't tell you for sure. It's for 3/8" Tube.

You'd have to cut the cable there (no biggie), then cut the Insulation back far enough to get some length. I would NOT try to cut the Insulation back far enough to get the longest conductor (white with Green Stripe, I seem to remember....?) to reach the end of the Primary - instead, cut the conductors evenly (after photographing the wire colors and locations on each incandescent bulb), then solder new wires on each conductor and run them up to their positions on the PCB on the inside.

Mind the polarity, as 3 of the bulbs work off 1 side of the circuit, and the 3 others vice/versa.

When you are done, call me and tell me what YOU think that job would be worth....

As I've said before, give me a call if you want me to walk you through it.

All the best,

Kevin.

rdmmdr

hi kevin

knew you are the man for this.

rick m

Larre Ländin

Thank you both Rick and Kevin,

I can verify that the cable is 3/8" and the SL order number seems to be correct. On Monday I will call the Swedish SL distributor to see if they can supply me with new parts. If I run into problems I might take you up on your offer Rick.

Kevin, thanks for the tip about not cutting the whole insulation. I am not sure I would have thought of that and I dont want to shorten the cable too much.

Regarding the job, I am actually very happy with doing it myself IMO it's more fun to service and rebuild the rig than diving it . So I am sorry Kevin but you will probably never see my rig in your shop allthough it would be a great honor. However you will allways be my preferred supplier of odd Mk15 parts.

Thats it for now, as soon as the job is done I'll update this post with some pictures and notes. It may be this week or ... well ... never. It depends on the next baby, arriving soon :-)

Best regards, Larre Ländin

rdmmdr

Larre

Before you assemble the new gland find a friend with a megger/ your local electrician might have one, your local motor shop will have one and meg the cable. it is surprising how many bad cables will pass with a ohm metter that will fail after shooting with a 500 volt megger. anything less then 5 megs and the cable is toast. only do this with both ends disconnected. For those that have never used a megger, you cannot get hurt even at one thousand volts with the new electronic style but the old hand crank types will light you up if you are not careful.

have fun

rick

Larre Ländin

Oh, I have one more question:

I managed to save some of the oil that were in the housing but even before I opened the housing there were bubbles so I need more oil. I know that it is a special kind of mineral oil that is used but I don't know where to find it in Sweden. I read on a forum for computer modders that they used babyoil which is easily available.

In the article Modifying a Meg for Deep Dives Cedric Verdier uses ordinary Johnson Baby Oil, is this common practise or should I use something else?

Best regards, Larre

heyydude

Larre,

Don't use Baby Oil. There is fragance and other additives.

If you can't find "Parrafin Oil" in your neck of the woods, let me know, and we'll see about sending some.

Kevin.

Larre Ländin

Thats great, I think I have a bottle of that lying around here somewhere otherwise I am sure that they have it at my local paint shop.

Thanks again, Larre

koputai

And don't forget, the little bubble is there for a reason. Don't totally fill the housing.

Cheers,
Jason.