19-Set Vario/Aerial Base Mounting Plate

[Chris Suslowicz]

Ah, excellent! My plate is almost certainly a later version than that (or has been given an all-over repaint post-WW2). It's also missing all of the bolts, but now I know what they look like I can make some up to suit. The missing bolt on your plate may be deliberate - the one under the front of the variometer is difficult to access so may have been omitted (or they assembled the variometer to the plate and found they could not then fit the bolt).

The circular stamp is almost certainly an inspection mark.

Thanks for posting the photographs, very useful.

Chris.

[David Dunlop]

Thanks for posting your photos, Patrick. They indeed answer a huge number of questions about what we now know are Plates, Mounting No. 1, complete with their ZA-Number.

Chris is correct, the small black circular stamp is an inspection mark from whatever factory made these plates. It should say INSPEC MECH around the rim with the number of the actual inspector in the middle. For certain, RCA did not make these plates as their stamp would also have been present - another black ring with RCA in the middle.

Interesting that the underside of the plate is unfinished, other than the either cadmium or zinc plating. I think I spotted a bit of paint overspray on one of the underside edges and am wondering now if the normal state of these plates was actually plain plated metal, with no factory painting, like the Seating Plates No. 4 used to mount the variometer on the Truck and Ground Installation Carriers. I have a call into my friend here in Winnipeg to check his plate in that regard.

Nice shot of the connector between the variometer and aerial base as well. Whenever you have a chance, can you take some measurements from it for me? The diameter of the cable itself and the length end to end where it stops inside the end connectors. Interesting that two different end connectors are shown. I suspect the one at the aerial base end was a replacement at some point. It is a solder type and would take a bit more work to install. The one at the vario end is a crimp on style and, I think, another Ross-Courtney product. Probably the original factory fitting. At the aerial end, is that a small yellow collar hiding up by the end connector. Sometimes these have a part number ID in black letters printed on them but on smaller cables the ID information is usually not applied.

I was expecting the usual three BSF countersunk slot head screws to mount the variometer assembly. Interesting they went with the BSF hex head bolts, and I notice they are all the thinner hex head type, not the more common fat head jobs.

Are the four retained fasteners that mount the plate assembly to the top of the transceiver slotted cheese head screws, or also hex head bolts?

As I said, Patrick, a whack of info in your photos! Thanks again for posting.

Now we need to get the title of this thread changed to read:

Plates, Mounting No. 1


David

[David Dunlop]

Just got a response back from my friend here in Winnipeg about his Plates, Mounting No.1 and he confirms an unpainted underside. The top of his has been painted flat black by hand at some time. One can make out some brush marks on the larger surfaces apparently and some drips down the edge on one side, so his might have been all plated metal originally. Chips in the paint show plated metal beneath and no sign of a primer.

Thin head hex bolts used for all three items attached to the plate.

Chris: I have seen those little spring retainers on the four hex bolts BA No.2 that bolt the assembly to the top of the transceiver used with some other piece of equipment at one time, but I am beggared if I can remember what piece of equipment! Whenever you get around to tracking your Plates, Mounting No.1 down, can you spec out these four BA No.2 hex bolts for us? Total shaft length, length of thread and how far from the head the retaining clip slot has been cut?

When I think of it, it makes sense they used thin head hex bolts to mount this Plates assembly. Not enough room around the variometer to get at cheese head slotted screw with a screw driver. Would think one has to be careful tightening them, however. With the shaft cut for the retaining clips I could see the bolts shearing easily at that point if you had some knuckle dragger working the spanner!

David

[Chris Suslowicz]

Originally Posted by David Dunlop

Just got a response back from my friend here in Winnipeg about his Plates, Mounting No.1 and he confirms an unpainted underside. The top of his has been painted flat black by hand at some time. One can make out some brush marks on the larger surfaces apparently and some drips down the edge on one side, so his might have been all plated metal originally. Chips in the paint show plated metal beneath and no sign of a primer.

Thin head hex bolts used for all three items attached to the plate.

Chris: I have seen those little spring retainers on the four hex bolts BA No.2 that bolt the assembly to the top of the transceiver used with some other piece of equipment at one time, but I am beggared if I can remember what piece of equipment! Whenever you get around to tracking your Plates, Mounting No.1 down, can you spec out these four BA No.2 hex bolts for us? Total shaft length, length of thread and how far from the head the retaining clip slot has been cut?

When I think of it, it makes sense they used thin head hex bolts to mount this Plates assembly. Not enough room around the variometer to get at cheese head slotted screw with a screw driver. Would think one has to be careful tightening them, however. With the shaft cut for the retaining clips I could see the bolts shearing easily at that point if you had some knuckle dragger working the spanner!

David

I suspect the retaining clips are the same as those used on the WS19 control units, and possibly the supply unit retaining screw. That may be a suitable source of patterns for the clip, although they all use "fillister head" screws.

My plate came as a bare plate, no screws or clips.

All the early/unissued mounting hardware that I've seen has been 'bright', i.e. unpainted (plated) steel. I suspect it was painted to suit the application prior to installation. The post-WW2 hardware seems to have been supplied in green finish.

I'm somewhat surprised that lock washers are not fitted to the various bolts.

(My suggestion of "Plate & Bracket Assy No.1" came from Wireless for the Warrior Volume 2, where it is used throughout. It may be a mistaken designation for the bracket used for the "Condenser X5, 5kV" used with the RF Amplifier No.2, but I'm not sure of this. I wish we had more "Comm. Inst." EMERs (i.e. more than zero) available for the WW2 kit.)

Chris.
(Still gap-filling the "Satchel, Signals" collection - I currently have numbers 1, 2, 3, either 4 or 5, 6, 7, 8, 10 and 12! I have no idea what went in No.8, possibly a test meter of some sort. There are several variations of the No.1 and at least a couple of the No.2 satchel.)

Chris.

[David Dunlop]

Chris.

I will chat with my friend here in town and see if we can get some specs off of one of his retaining bolts. He is missing one himself (his Plates Assembly, not him) and I was chatting earlier today with Mark at British Fastners out your way. He can make up a small batch of these BA2 hex bolts no problem, if he has the right specs. Can't help with the wire spring retainers, however.

David

[Chris Suslowicz]

It's possible that the "Plate & Bracket Assembly" is an earlier version of the "Plates, Mounting", since the drawings in WftW Volume 2 do not show the rectangular notch at the left hand end of the plate. (This was needed to provide clearance for the very long (wrap-around) strap used with Carrier No.25, which started at the LHS of the supply unit, went under the carrier, around the set, under the "Plates, Mounting" and mated with an adapter plate(1) fixed to the top of the supply unit.)

I think this plate may also have been used to fit the 'double-sized' Control Unit No.3 on top of the set in the Daimler Scout Car (though it's possible that a shorter plate or even a wooden block was used).

Chris.

(1) If anyone has one of the adapter plates, shaped like the profile of a house with four holes in the 'roof' part to match the ones in the top of the supply unit, and two keyhole slots to match the adjustable plate on the clamping strap, I'd be very interested. Just the measurements would do! (The plate is necessary because the keyhole slots in the supply unit - intended to fit it on top of the WS19 for Universal Carrier use - point the wrong way for Carrier No.25.)

[David Dunlop]

With regards to the captive screws used with the Plates, Mounting No.1, it is possible the retaining clips used on them are known as 'Circlips' and as Chris suggested, they are indeed used as part of the mounting hardware for the series of Wireless Set No. 19 Control Boxes. They are listed as: Circlips No. 2, ZA 14719 and are used in conjunction with Screws, Captive No.7. I have yet to find any specifications on these particular screws.

Screws, Captive No.5 are used to lock the PSU into it's case and Screws, Captive No.4 are used to mount the 19-Set Transceiver into it's case. In both of these items, the screws are held captive by first threading through their respective face plates. No retaining clip is fastened around the screw shaft.

David