C-42 Set Dummy Load

[David Dunlop]

I think this item may also be referred to as "Simulator Aerial Tuning Unit No. 1" as the ZA 46625 Number appears to refer to both nomenclatures.

My Radio Station C42 Instructional (ex Cdn Army) has been missing this piece since I purchased it some 20 years ago. Never thought much about it, but the four empty holes on the rack are starting to call to me now.

Based on the photos in the Operators Handbook, the C42 Dummy Load looks externally to be identical to the standard Aerial Tuning Unit No. 6, so I am assuming the differences are all internal.

If the dummy load cannot be found, can anyone advise what I would need to do with a standard ATU No. 6 to convert it, or at least make it look like a Dummy Load?

David

[Jon Skagfeld]

I believe I recall that the item you're looking for is/was painted gloss grey.

In our Signal Corps unit we had a full classroom set up with C42s for instructional purposes. I can't recall us ever having these items, nor can I recall how the dummy load was set up.

I too searched for ~20 years for one and came to the conclusion that they were unobtanium.

[Chris Suslowicz]

I did actually see one last year in an SK auction.

(I don't know who bought it, though.)

They are indeed painted grey.

Chris.

[David Dunlop]

According to the Installation Instructions (photo attached), the C42 Aerial Simulator (Dummy Load) uses special mounting hardware as highlighted in Item 3 of the photo. Four hardware sets are required and they appear to be made up of a two part standoff insulator/spacer with a screw or bolt passing through it. The only reference I can find in the instructions to these parts are the ZA Numbers for the two pieces of the insulator/standoff: ZA47035 and ZA47036.

Can anyone identify what these two items actually are and the size of the bolts needed to secure them?

Secondly, does anyone know a source of supply for these standoff/insulators?

Thanks,


David

[BCA]

Jon, I specialize in unobtainium. Pm me if you need a C42 Aerial Simulator: NOS of course! .... Brian

[David Dunlop]

OK. So following a large pail of tea to start the day, I had another read of the C42 manual and found the following references to the mounting hardware for the Aerial Simulator (Dummy Load).

ZA 47035 (5340-99-949-1084) Bushing, rubber, 0.3280 in id x 1/2 in od x 1-13/32 in lg

ZA 47036 (5340-99-949-1043) Bushing, rubber, 1/2 in dia hole x 3/4 in sq body x 1/4 in o/a lg

A process of elimination leads to the hardware used possibly being: Screw, cap, hex hd, low carbon, st. cad. or zn pl, 1/4-20UNC-2A x 2, with corresponding flat washers (8) and nuts (4).

Seems there is a need to make sure the body of the Aerial Simulator is not in contact with the main C42 set metal mounts. Impact shock or electrical? Hhmmm. The manual does warn never to use the set on high power when operating through the Aerial Simulator.

Wonder if there is any chance those bushings are still in the system.

David