19 Set Cable Gasket

[David Dunlop]

Does anyone know when that strange conical rubber gasket on the A Set and B Set output cables is actually put to use? It is usually fitted close to the Pye connector on the end of the cable that does not have the brown ID sleeve, but clearly is capable of being slid along the cable as needed.

It does not look like it is intended for when the cables are fed through any of the canvas set covers. Looks more like it is for protecting the cables when they need to be routed through a metal box or cover.

Sorry. I have looked at them for over 40 years. Finally had to ask.

David

[universalgrl]

You mean one of these (see pic).
It's shown on page 20 of EMER FZ 256/2 as part of "installation kits W/S CDN no. 19 truck and ground" item # 30 grommets, rubber no. 23

[David Dunlop]

Hi Roberta.

Actually, it is this little beastie found on nearly all aerial connectors I have seen for the 19-Set A and B output terminals.

David

[Jordan Baker]

The type pictured by David does fit into the B set antenna bracket on the Mk1* UCarrier.

[universalgrl]

Ok then where does the rubber grommet # 23 fit???

[David Dunlop]

Roberta.

Does it mention the #23 Grommet in the actual installation instruction at any point?

David

[David Dunlop]

I took a look at my cables and found that the B-Set cables I have are all NOS and have been assembled in the same format. The brown label sleeve is located against the straight Pye Connector. This label is actually the "TUNED LENGTH DO NOT CUT" warning. The ID tag for the cable is the small metal black and silver tag crimped to the cable with the ZA Number for the cable on it. It is fastened within the half of the cable at the elbow Pye Connector end. This strange rubber grommet is installed with the round end against the elbow Pye connector and the cone pointing towards the straight Pye connector end of the cable, so it would seem that in some installation situations, this orientation is critical.

To add a second layer to the puzzle, my A-Set Pye cable (between the set and the variometer) also has this rubber grommet installed. See photo. One elbow connector has a brown ID sleeve up against it. The rubber grommet is installed with the round end up against the elbow Pye connector at the opposite end of the cable, with the cone pointed towards the brown sleeve. For the Ground and Truck installation, the orientation of this A-Set cable is irrelevant, but there must be some installations where orientation is critical.

One last wrinkle. While examining these cables this morning, the look of this grommet started to bug me with it's familiarity. Went down to the Wireless Room and lo and behold, the same grommet is also used on 19-Set Control Boxes to protect the head set leads passing through the side of the box. In this application it is held in place by a circular cadmium plated retaining ring and two small screws. See second photo. I have looked at all available grommets of this style in my collection and none of them have any markings on them at all.

Jordan.

Do the Installation instructions for your carrier mention this grommet and how/why it is to be installed?

Cheers


David

[Chris Suslowicz]

I think the coaxial cable (long) grommets are to protect the cable where it goes through a metal plate (e.g. vehicle bulkhead or roof).

The No.23 grommet has a much smaller hole and is most likely for the wire aerial feeder (No.9?) on the truck and ground station. It looks about right for P11 cable between the aerial base on the vehicle and the rigid aerial base on the Carrier No.3 mounted set.

Chris.

[David Dunlop]

Hello Chris.

The Ground and truck Installation instructions are a bit vague. Only reference is that if grommets were not supplied, use electrical tape to protect the cables, but not at all clear what grommets, what cables or where. Must, as you suggest, be where passing through sheet metal structure, not heavier plate. Somewhere I have a detailed Parts List for the Installation Kit. A big 8.5 inch by 14 inch sheet of paper. I will try and find it and see if any type of grommets are listed.

David

[Chris Suslowicz]

I suspect the grommet is a water seal that goes under the aerial base No.8 or 10 on a vehicle roof. It's shown in EMER FZ256/3 of 1st October 1944 for the Canadian WS19 Mk.III, but I've not seen where it's supposed to be fitted. Probably need a late set of installation instructions for one of the "house type" radio bodies to be sure - they had a flat plate on a stand-off from the roof (two or three on each side) and I have an adapter plate to convert a 6 hole mounting to 4 bolts for the 'B' set aerial base mounting. I would imagine the grommet plugs the hole in the roof and is high enough to stop water getting in - the central hole is far too small for co-ax and I think Aerial Feeder No.9, which is P11 rubber covered multistrand like the battery leads with a ring terminal on one end for the connector plate under the aerial base and a plug to mimic the end of an aerial rod for the set end.)

[Chris Suslowicz]

I have been reading the Truck & Ground Station working instructions.

Paragraph 42:

"(42) Place the Waterproof Cover No.5 over the equipment ensuring the Leads, Aerial No.3 passes through the grommeted hole provided. Fix the rubber grommet on the Leads Aerial No.3 into the hole in the waterproof cover, also pass the lead of the Aerial Feeder Assembly No.9 through the hole provided for the Antenna Rods G [This is almost certainly a typo for 'F'] at the rear of the supply unit and plug into the socket immediately below."

OK, so that's the grommets on the coaxial cables sorted (they fit to the canvas covers to stop rain running off the canvas and through the cable entry holes). Simples! (Squeak)

Grommet No.23 is not mentioned in this pamphlet (which is the 1943 Canadian one), but appears in the 1944 Parts Identification EMER FZ256/3. My suspicion is that that fits into the cable/aerial rod 'F' hole on top of the waterproof cover at the rear of the supply unit, and is intended to keep rain from running down either the Aerial Rod F, the Leads, Aerial No.5 (when used to connect the set to the 34-ft mast), or the wire aerial feeder, and shorting out the paxolin aerial base, etc.

If Roberta could check her grommet (to coin a phrase) I suspect she'll find the bottom 'F' rod or a wire aerial feeder cable is a good fit for the central hole. Also the grommet should be a tight fit in the hole on top of the waterproof cover No.5.

I don't have a Grommet No.23 or I'd be able to test this; anyone got a spare?

Chris.

[David Dunlop]

Chris. You have been doing some nice detective work. One quick question. The No. 5 Cover. Is that the big one intended for use with the large wooden carriers? If so, I had always wondered about the large hole to the rear of the PSU. It is fitted with a square of brown leather but the opening is still quite large for inclement weather. If the No. 23 Grommet of Roberta's fits that opening, that is a great discovery and something to keep an eye out for in the future.

David

[Chris Suslowicz]

That's the one, the sort of tent arrangement for Carrier, Set, No.3 (or 23).

Chris.

[universalgrl]

The rubber grommet # 23 is a perfect fit for the large opening in the # 5 cover. It's the correct size fit for the F rod. but I don't think it would fit the cable going out to the mast.
If you are lucky enough to have both pieces use a good rubber or O ring lubricant (not ky HA HA), the grommet was good but the cover piece was starting to crack.

Here's another question. I have the # 16 ZA 28542 and # 17 ZA 28543 control box for my 38 AFV installation, but I found another # 17 ZA 24891 box that is marked 510 not 38. Would that be for the CDN 510 set.

Both of the first 2 boxes are tropicalized which is a good thing on the west coast as it's currently coming down in biblical sized buckets right now.

[David Dunlop]

Nice work, Roberta. That grommet looks right at home! Looks like I have to add another fiddly bit to my 19 Set Needs List. I always assumed it would get shorter over time. Good to know the correct way these things are supposed to go together.

David

[Chris Suslowicz]

Originally Posted by universalgrl

The rubber grommet # 23 is a perfect fit for the large opening in the # 5 cover. It's the correct size fit for the F rod. but I don't think it would fit the cable going out to the mast.
If you are lucky enough to have both pieces use a good rubber or O ring lubricant (not ky HA HA), the grommet was good but the cover piece was starting to crack.

Here's another question. I have the # 16 ZA 28542 and # 17 ZA 28543 control box for my 38 AFV installation, but I found another # 17 ZA 24891 box that is marked 510 not 38. Would that be for the CDN 510 set.

Both of the first 2 boxes are tropicalized which is a good thing on the west coast as it's currently coming down in biblical sized buckets right now.

Hmmm, I think you'd do better with a leather preservative if the gasket on the cover is starting to crack.

On the control unit front, ZA.24891 is Control Unit No.17 (The original "Mk.1" version and would have had fabric covered dropleads. ZA.28543 is the Mk.1/1 with rubber leads and tropic proofing, while ZA.38153 is the Mk.2 presumably with the WS38 or 88 / WS31 or SR B40 switch.)

The AFV control units (16, 17 and 33 (the last one being for command tanks with 2xWS19 and an AFV set)) were used with the WS38 AFV, WS88AFV, WS31AFV, CPRC-26, and I suspect your example is for the Australian A510. All those sets required an external audio amplifier, and the first three had a combined PSU and AF amplifier unit. I think the CPRC26 relied on dry batteries for power, and probably the A510 did as well. The WS31 had power units/LF amplifiers in both 12 and 24 volt versions, but the WS88 version was only produced in the 12 volt version.

Wireless for the Warrior Volume 2 is your friend for all this stuff.
Louis spent decades researching this stuff and I don't know what we'd do without them.

Chris.

[David Dunlop]

You are going to have to go back to wherever you found that No. 23 Grommet and try and corner the market. There are probably a few of us could use one.

David

[universalgrl]

Dave
I bought the grommet where else but epay, and it's the only one I have seen. If there is anyone out there who is good at rubber casting that may be the way to go.
I will check out industrial paints and plastics in town, I know they have casting and moulding kits.

[David Dunlop]

Hey Roberta.

Can you post a profile photo of the grommet whenever you have a chance and advise what the country of eBay origin it came from? No rush. Whenever you have your feet up with a glass of fine wine and are looking for something to do...

David