Wireless of the Week - week 5

[Robert Bergeron]

Well done Bruce, well done.

[Johnny Canuck]

Great work as always Bruce.
Have a few odd items to add.

'G' Rod Bird Cage





British 'D' Rod Aerial Set the predecessor to the Canadian 34' Antenna Set










'D' Rod stabilizer used on vehicle installations.





Geoff

[Bruce Parker (RIP)]

Thanks Geoff, it's great to see other stuff added to the overall knowledge mix...kind of why I'm doing this.

Interesting B 'birdcage' brush guard. I'm fairly certain its British. The Canadian ones had an entirely different clamping system onto the aerial base and were made from rectangular instead of half round metal stock.

[Chris Suslowicz]

The "Protector, Aerial Base" for Base No.9 was a late addition to prevent the base being destroyed by low branches, etc. A large number of them would have been made up "in theatre" out of materials in hand, so the actual construction could vary considerably.

I think the "BRACKETS AERIAL CLAMPING No.1 T. ZA29558" is for fitting an elevated aerial base to the top of a 'D' rod, since it looks very similar to the "F" rod adapter for the the British 34-ft mast. It's odd in that it has four slotted lugs, which would not appear to match up with the usual aerial bases, and is quite late from its stores code - late 1944-ish. It looks as though it's intended to be rotated onto some studs for clamping, but I don't really see why. It certainly won't fit any of the usual bases, though possibly the No.3/No.16 combination for radio trucks - but the reason for it escapes me at the moment.

Chris.

[Johnny Canuck]

Hello Chris

The BRACKETS AERIAL CLAMPING No.1 T. ZA29558 is for the top of a vehicle roof, I think??, only reference I've seen for it is in WFTW. Appears to have been used in LCV's and ACV's 4x4 HP RCA/19, one of the aerial connections on the Wireless Sender RCA ET 4332 B includes the following, Connector Single No.46, Insulator W.T. AE Lead-in No.16, Adaptors No.2, 4 or 5, Main Rod Aerials as required. I'm assuming they are referring to 'D' Rods, as the other aerial connection on the RCA set is for a Dipole No.9 which requires something heavier than an 'F' Rod set-up.
The above parts are listed in WFTW as being for ACV's & LCV's, also 'D' Rods were originally used for WS 1, 2, 3, 7, 9, and 11; all old school, later the WS22 used 'D' Rods as a 34' antenna/dipole mast set-up for Ground Stations.

There is also a reference in the WS53 chapter, picture is poor, ZA number is different ZA.24136 and "it is mounted with 'F' and 'D' Rods to the insulator fitted to the roof'"
It also states in WFTW that anything over 18' (6 'D' sections) required stays, 18' is a lot of torque and the Brackets Aerial Clamping would have stabilized the 'D' Rod antenna base/insulator, keeping it from ripping the roof mounting plate out in anything stronger than a light breeze.(Used only when vehicle was stationary)

I set up the pieces roughly to give an idea of how they might have worked. The Mounting would have had to be insulated from the vehicle as it is clamped directly to the 'D' Rod.
Also the 'F' Rod adaptor would have had to be installed at least one length of rod above the stay plate; as you can not turn the thumb screw on the adaptor when the stay plate is directly under the adaptor.

Anyways sort of like this, diameter of bracket is 8 5/16".







Geoff

[Chris Suslowicz]

Riiiiiiiight.... all becomes clear.

It fits on Aerial Base No.16, which consists of a (modified?) Aerial Base No.3 on top of Insulator W/T "H" (which is a substantial ceramic piece). This was intended for (relatively) high power sets (WS19HP, WS12, WS53, etc) and the Aerial Base No.3 was not up to the job of insulating that much voltage. So: the ceramic (W/T 'H') provides the insulation and feed-through into the vehicle, and the No.3 is bypassed by four braid straps and just acts as a vibration mounting.

This is fine for a few 'F' rods, but once you start stacking 'D' rods, the hollow rubber Base No.3 will collapse, so you need that bracket to support the weight of the vertical aerial. Obviously you can't use it on the move, and since it's only supporting the weight of the rods, it doesn't need to be fastened on (certainly not bolted down, anyway).

I'm currently cleaning up a Base No.16, and noticed it has four large flat-headed studs on the clamp ring, so that's obviously what the slotted lugs on the bracket mate with. (Drop it on top, rotate into place, feed your first 'D' rod in and tighten the clamps on base and bracket, then add more rods as required. (Or fit the bracket to the assembled vertical before lifting it into position, then slide down, rotate, and clamp in place.))

Once I've got it cleaned up I will see about some photographs of it.

Chris.
(And that bracket is something else to look for on this side of the pond.)

[Chris Suslowicz]

Aha! I seem to have two variants of Aerial Lead-in No.16, plus the mounting hardware for both types.

The first type is for "15cwt 4 wheeled Wireless Truck Mk.III" and fits on a bracket over the cab. Feed is via a "blackout box" on the end wall and an "Insulator W/T lead in No.12" (two glass dome insulators in a square panel).
The four braid straps that bypass the rubber insulator on Base No.3 are fitted to the top clamping ring. See WftW Vol.2 Page WS19-74 which is for a (British) WS19HP install.

The second type is for "House Type Body" wireless trucks (15 cwt Mk.II), LCV and ACVs, and the post-WW2 Austin K9. This fits to a paxolin plate in the centre of the roof and is fed directly through the base. (It allows the safe use of rather higher powered transmitters like the WS53 and RCA 4332 and BC-610, where the feeder can go straight up from the set to the base and be protected by an earthed metal guard.) For this version, the braid straps are fitted to the plate that the Base No.3 is clamped to, and the clamping ring has gained the studs that the "Bracket, Aerial Clamping" fits onto. (It has to rotate anticlockwise (viewed from above) because the studs for the (now unused) braid connections are next to the new ones for the aerial bracket.)

Photographs of all this stuff once I get the camera sorted out and the "first type" of base unearthed and cleaned up!

Chris.

[Chris Suslowicz]

Originally Posted by Johnny Canuck

...I'm assuming they are referring to 'D' Rods, as the other aerial connection on the RCA set is for a Dipole No.9 which requires something heavier than an 'F' Rod set-up.

Aerial, Dipole No.9 (and its siblings, 9A and 9B) is a wire aerial supplied on a wooden board (like the ones used with the WS19), but it has a large (and rather heavy) dipole centre consisting of a circular bakelite block with protruding metal bars and wing nut terminals, and a coaxial Niphan connector for the feeder. To make matters worse, the feeder is the traditional Duradio No.1 co-ax as used for the WS19, and also uses Niphan connectors. This is extremely heavy compared to a standard wire aerial, and needs the 36-ft steel masts (the sections carried in racks on the side of the vehicle) instead of the 34-ft type made of 'D' rods.

Chris.

[Jordan Baker]

Just had these arrive in the mail.

The left one I've seen before but the right one I've never seen. It looks to be a manufacturers instruction booklet. Comparing the two there are a number of different diagrams for setting of the antenna.

[Hanno Spoelstra]

Originally Posted by Johnny Canuck

Great work as always Bruce.
Have a few odd items to add.

Geoff,

A great addition to a fantastic series of wireless threads.

One thing I would like to ask you is to attach pictures to your posts rather than using links to Photobucket - we have learned the hard way that one day sooner rather than later they will disappear making this thread worthless.

Here is how you learn how to post images - let me know if you have any further questions.

Thanks!
Hanno