Antenna support, aluminum

[Colin Alford]

Gents,

I have found CMHQ files "55/5091/1 Antennae" and "55/5091/1/2 Antennae" They can be found at:
https://heritage.canadiana.ca/view/o...7/3734?r=0&s=3

The documents were placed in the file in reverse chronological order so if you intend on reading the entire file it will be best to start at image 3910 and work backwards to image 3734, skip to image 4085 and work backwards to 3911.

Specifications:

Specification O.S. 52 - Antenna, Vertical 34 Ft. Steel (Canadian Telescopic) Ref. No. PC 82495C-190 dated 5-11-42 can be found at images 3807 - 3824

Specification O.S. 145 - Antennae, Vertical 34 Ft. Steel Mk 1 Ref No. P.C. 82495C-300 dated 1 May 44 can be found at images 4004-4025

Updated Specification for electrical tests dated 14 Dec 44 can be found at images 3920-3921.

Nov 1942 User Instructions can be found at images 3826-3832

Design Change Instructions:

Can be found at images 3923, 3925-26 "Since the base is sealed during manufacture, it cannot be assembled in the field", 3954, 3957, 3961, 4026, 4028- 4031, 4050, 4052; and 4057-4059.


I will need to re-read the documents to properly digest the contents.

My initial impressions: The "First" specification from 1942 describes the Steel Aerial Base (I presume that this means the Campbell manual from Feb 43 will also describe the steel base). This would seem to indicate that the Aluminum base was not part of the "First" kit.

It seems that the Aluminum Base has a lower PC number, but a higher ZA/CAN number than the Steel base. Could these Aluminum bases have been produced and trialed during development of the 34' Steel Antenna, but initially deemed unsuitable, then at some later point they were taken into service and allotted a ZA/CAN number?

The two main specifications mention NDHQ file numbers "89-4-18" and "HQ 9070-12-17". There is some potential that these files are available online and might provide some pre-production development info.

Conclusion: More research is required!

Colin

[BCA]

Thank you Chris and Colin. I add that the early aluminum style (Chris's #1 model) has an assembly number (according to my Canadian microfiche) PC 82495 C224, 5955-21-106-4113. I agree with Chris that the upper portion is -220 and the lower portion is -222. This lightweight version is certainly easier to store and use.

[Chris Suslowicz]

Originally Posted by BCA

Thank you Chris and Colin. I add that the early aluminum style (Chris's #1 model) has an assembly number (according to my Canadian microfiche) PC 82495 C224, 5955-21-106-4113. I agree with Chris that the upper portion is -220 and the lower portion is -222. This lightweight version is certainly easier to store and use.

I think the PC stands for Procurement Catalogue, the 82495 is the 'group' number for the complete unit, the C to indicate "Canadian" and the -nnn is the individual component number (allocated sequentially by the designer).

On that basis:

PC84295C-224 is the Mast Insulator (lightweight)
- composed of -
PC84295C-220 upper casting
PC84295C-221 probably the glazed ceramic insulator
PC84295C-222 lower casting
PC84295C-223 probably the knurled screws for feeder connections

this is an earlier design/specification than the steel with phenolic insulator:

PC84295C-285 Base, Aerial Assembly
PC84295C-286 top casting
PC84295C-282 bottom casting
PC84295C-28? locking lever
PC84295C-28? pivot pin for locking lever
PC84295C-28? Phenolic impregnated paper insulator
PC84295C-2?? knurled screw - may be -220 as existing part

The final (ceramic) insulator specified for WS52 and WS43 (etc.) is:

PC84295C-295 (Which I suspect should really be designated the Mk.I*
because Mk.I is the first model issued (and becomes the Mk.I when a modification is made, which this certainly counts as).)

I need to find the various working instructions (etc.) for the mast kit, and see what level of detail is shown. A "Parts Identification List" would be good, of course, and may exist on that wonderful microfilm. (Which has interesting details about other things I wasn't aware of (such as the non-existence of Aerial Base No.19 - that was produced as a proposed replacement for Aerial Base No.10 Mk.2 that allowed the aerial to tilt, made it into various installation kit lists, but was abandoned in favour of Adapter, Aerial, No.1 ZA.27220 as an addition to the existing Base No.10 Mk.2.)

I have a library (of sorts) to search and sort/catalogue, but not tonight!

Best regards,
Chris.