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Old 01-07-16, 01:19
Bruce Parker (RIP) Bruce Parker (RIP) is offline
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Default Wireless of the Week - week 20

The Wireless Set No.29 is a Canadian re-design of the standard 19 set. It was produced in Canada by RCA in Montreal beginning in 1945 but was too late to see wartime service. While incorporating many advanced features, the set was obsolete before it had a chance due to military radios adopting FM VHF frequencies over AM HF ones. Serial numbers indicate less than 1000 sets were produced and there are perhaps a half dozen surviving examples making it one of the rarer Commonwealth wireless sets. The rumour for so few survivors is that the radium in the dials made them a little too ‘hot’ for post war ham operators and most of the sets were buried in the Chalk River nuclear facility near Ottawa.

The remarkable thing about the 29 set, and a criteria that must have driven its developers nuts, was that it not only had to do everything a 19 set did (or better) including frequency range, operating on RT and CW and having an A set, B set and intercom, but it also had to fit into the exact same space and mount every component…from the aerial bases, to the control units to the set itself…in existing 19 set holes. It was even compatible to existing 19 set installations in armoured vehicles and trucks; you could replace the 19 set with a 29, and still use all the existing cables, connectors, control units and aerials from the 19 set as-is. The 29 set did, however, have its own unique aerials, control units, headsets and accessories. Again similar to the 19 set, the 29 ran on either a 12 or 24 volt DC supply manually set by an internal switch.

The set itself was configured a little differently however. Unlike the 19 set that had the power supply unit on the left and the sender/receiver (made up of the A set, B set and Intercom portions) on the right, the 29 set had the A sender/receiver on the right, the power supply in the centre and the B and intercom combined in one unit on the left. This last unit could be used as a stand-alone set if required.

The A set operated between 2 and 8 MHz just as the 19 set did, but had a somewhat complicated method of setting the frequency. The operator had to first set the RF dial to one of 12 fixed positions spaced 500 kHz apart (2.0, 2.5, 3,0, 3,5 MHz etc.) just below the desired frequency, then complete the kHz adjustment with the oscillator dial using either a black or red scale depending on whether he was above or below the half MHz RF setting. It did, however, enable crystal accuracy eliminating the need for netting calls and the use of a crystal calibrator to establish a desired frequency. A key lock-protected high power setting increased the range from 8 to 10 miles on low power, to 20 to 25 miles on high, a feature which made it equivalent to the much larger Canadian Amplified and British High Power 19 sets. Another handy feature was the ability to preset three channels, red white and blue. Not only was this an improvement over the two 19 set ‘flick position’ pre-sets, the 29 set's selections were motor driven instead of mechanical so the tuner, oscillator and aerial tuning unit (variometer) would all move by themselves to the correct position with the push of a button on the face of the set. The B set had only two pre-set channels: 235 MHz and 245 MHz with a range of 1000 yards. The 29 A, B/IC and Supply Units are held on to the set carrier by studs and quick release levers which, if you’ve ever had to remove a 19 set from its carrier, you’d have to agree is a big improvement.

While not waterproof, the 29 set was splash and dust proof and solidly built. The cable connections were all secured with threaded screw-on rings at the connector’s ends and the control units are cast instead of spot welded stampings as 19 set ones were. When not in use, the set’s cable connectors were protected by screw on covers (see photo 1). Other simple improvements were incorporated to aid the operator such as colour coding the fuses to make their replacement easy and error free, and a meter that didn’t require the operator to know numerical values; if the needle was in the ‘red zone’, the reading was acceptable.

Here’s a video of the 29 set operating:

https://www.youtube.com/watch?v=4Kplkhbq3EE
Attached Thumbnails
1.jpg   2.jpg   3.jpg   4.jpg   5.jpg  


Last edited by Bruce Parker (RIP); 01-07-16 at 16:50.
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Old 29-07-20, 18:24
David Dunlop David Dunlop is offline
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Are there any indications the No. 29 Set was going to be a shared production item, like the 19-Set, or was it intended to stay an RCA Victor Canada product for its planned service life?

David
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Old 30-07-20, 14:31
David Dunlop David Dunlop is offline
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The reason for my inquiry earlier is a lead I received earlier this week through the local Amateur Radio group about an aerial tuner that turned up in town, made by Canadian Marconi Company. I should be able to pick it up this weekend.

The initial thought was it was likely another Coil, Aerial Tuning No. 2 for the 52-Set, but the general description suggests it is smaller than that and it has two separate aerial connections on the output side, from what I understand.

My next thought was it might be a piece of RCN Wireless gear as CMC was very active in that area, but I am told there is a ‘ZA’ Number on it and that the chassis is secured by a set of circular cams. That got me thinking of the 29-Set, but my assumption has always been that set was solely an RCA Canada project and was issued with a variometer, so would not require an aerial tuner.

Will know more about this thing when I pick it up and get some photos of it.

David
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Old 30-07-20, 15:29
Bruce Parker (RIP) Bruce Parker (RIP) is offline
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The 29 set had a 'variometer' similar in size to a 19 set one but with a big lobe on the side to house the drive motor. There is also an AERIAL MATCHING UNIT No.C1 in a square case about the size of the 29 set supply unit. Its number is ZA/CAN 9268 CMC 105-969 with no maker specified on the data plate as "RCA VICTOR COMPANY LIMITED' is displayed on other components of the set. Safe to assume it's Marconi however.

Both aerial units are shown on top of the 29 set. Note the 52 set style tuning knobs on the C1 unit.

I have no idea whether it was planned to have Marconi produce sets, a possibility perhaps if the war had gone on longer and thousands of sets might have been required to replace 19 sets. But as it turned out of course nothing came of it.




Quote:
Originally Posted by David Dunlop View Post
The reason for my inquiry earlier is a lead I received earlier this week through the local Amateur Radio group about an aerial tuner that turned up in town, made by Canadian Marconi Company. I should be able to pick it up this weekend.

The initial thought was it was likely another Coil, Aerial Tuning No. 2 for the 52-Set, but the general description suggests it is smaller than that and it has two separate aerial connections on the output side, from what I understand.

My next thought was it might be a piece of RCN Wireless gear as CMC was very active in that area, but I am told there is a ‘ZA’ Number on it and that the chassis is secured by a set of circular cams. That got me thinking of the 29-Set, but my assumption has always been that set was solely an RCA Canada project and was issued with a variometer, so would not require an aerial tuner.

Will know more about this thing when I pick it up and get some photos of it.

David
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  #5  
Old 30-07-20, 16:24
David Dunlop David Dunlop is offline
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Interesting, Bruce, thanks for that. When I get this item home I will post photos of it.

The “105” prefix number block shows up in the 52-Set Parts Lists from CMC for the meters used in the set.

Now my curiosity is peaked regarding why the 29-Set was issued with both a variometer and an aerial matching unit. Technically, they both do the same job, but perhaps a variometer has better efficiency with tuning whip aerials and the CMC Matching Unit was better working with long line horizontal aerials in a Base Station environment.

Do the mysteries ever stop, Bruce???

David
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Old 16-08-20, 17:16
David Dunlop David Dunlop is offline
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Default Aerial Matching Unit No. C1 ZA/CAN 9268

This little gem arrived on my wireless bench last week and I finally had a chance to take a quick look at it. Never knew they existed until this one arrived and I was even more intrigued that it was a Canadian Marconi Product built for an entirely otherwise RCA Victor Canada Wireless Set.

This one was used by somebody who thought removing a ¼-turn fastener and replacing two ceramic aerial terminals with UHF Sockets was a huge improvement. However, internally, it all still appears to be there.

The four screws on the right side of the case are, I suspect, mounting screws that allow the Matching Unit to be secured on top of the 29-Set A-Set Case. One screw is missing, but underneath it and that horrid aluminum paint is very original wartime Semi-gloss Olive Green paint as used by Canadian Marconi.

The screw on the back of the case secures a large guide pin that engages a set of holes in the chassis when it is being removed or returned to the case, to prevent damage to the tuning coils.

It is not until you see the tuning coil arrangement inside the Matching Unit that you realize why RCA called CMC in as a sub-contractor for this part of the 29-Set Project they had undertaken. The tuning coil setup is almost a carbon copy of the PA LOADING circuit Marconi used in the Sender of the 52-Set, and it had proved a very successful design. No need for RCA to have wasted time reinventing the wheel.

Interestingly, when I took my first close look at the Matching Unit, I had to smile when I read the Data Plate. The Serial Number is: C-52.

David
Attached Thumbnails
WS No. 29 Matching Unit 1.JPG   WS No. 29 Matching Unit 2.JPG   WS No. 29 Matching Unit 3.JPG   WS No. 29 Matching Unit 4.JPG  
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