Wireless of the Week - week 52
 

I said at the start I’d go until I ran out of radios, and with this week’s installment, I have. I began with a venerable 19 set and will finish with one.

This last week’s feature is a Canadian Wireless Set No.19 Mk.III on a wooden Carrier No.23. The features of the 19 set are by now familiar: 2 to 8 MHz A set with an 8 to 10 mile range, 229 to 241 MHz B set with a 1000 yard range, an intercom and two pre-set ‘flick’ positions. This particular set was made by Northern Electric in 1944.

The 19 Mk.III is the culmination of wartime improvements. It had slow motion control for tuning, improved netting, the ability to independently switch on and off the A, B and IC functions and a 12/24V No.2 Power Supply Unit that operated a rotary transformer as well as a vibrator for lower power consumption and less noise. Bilingual Russian/English face markings were standard though these were often replaced by English only lettering on post war rebuilt sets. Another post war modification was the removal of the plastic clock case on the Supply Unit. This was reputedly because a Signals Warrant Officer became fed up with the sloppy appearance of these as they became chipped and broken so ordered their outright removal. No matter, by that time all the actual time pieces had already been pilfered for personal use.

The wooden carrier with its waterproof cover was versatile allowing the set to be used as a ground station or, with quick release Mounts No.1, as a vehicle station and quickly moved between the two. Its wooden handles allowed the set to be easily carried by two men and the protective face guard protected it from damage. Everything including the variometer, No.3A or 3B Control Unit and power cable was attached so it only required hooking up batteries, aerials and headsets to get it going. The set on its carrier was 37” wide, 11” tall, 14” deep and weighed 105 lbs.

Next week I will post an index of the communication equipment I have presented to help find items of interest should you ever wish to revisit them.

I've just noticed.... The grille guarding the front of your 19 set has 6 vertical bars if I can count straight. The one I'm copying that Bob Carriere owns has 7. I believe the one you showed in week 1 is the 7 bar variant. Does anyone know the reason for the difference and is there a early/late, truck /armored vehicle or other divide to say which grille is appropriate for what?

There are 7 bars present, Grant. The extreme right (end bar) is hiding behind the canvas corner flap. You can just make out the curve of it running above the wood board.

David

True, thank you. This is a case of I'm very happy to have been wrong.
I started off thinking "wonderful, I have a pattern to work from" and then was starting to be scared I needed to do more research before going forward from bending parts to jigging and assembly.

Look closely, not a variant, 7th is behind the canvas on the right hand side.

Geoff

Ws19 mk2
 

Just a quick question. I have a 19 set mkII, with power supply and variometer.
I am interested in the junction box. Could you post a better picture of it please?
and the wooden mounting board if you could? I would be interested in seeing if I could make one for mine.

Thanks.
Jason

52 Wireless posts
 

Wow!

Who would have thought that "old" radios/comms equipment of a certain era could take a year to demonstrate/display/explain?

Good job Bruce. Many thanks.

Looking forward to the index so I can file it away in my favourites for future reference.

52 and????
 

Shucks was waiting for a write up and pictures for the R107 Reception set. Never the less You did a wonderful job.
Ben in Toronto

Jason.

Two or three years ago, somebody in either the UK, or Western Europe, was making excellent reproductions of the No. 23 Carrier. They might even have been mentioned somewhere here on the forums.

David

Carrier Wood
 

Sorry no measurement but have two picturesAttachment 88588

Attachment 88589

Well, Bruce's weekly threads made for a year of interesting reading. Thanks so much!

I add my thanks to Bruce for this series. Many of these sets have passed through my hands over the years and it was great to see them again.

It's a wonderful collection you have, Bruce. Your postings show that not everything is about rusty old trucks. :giveup

hello
Thanks for this presentation. A wonderful set.
You have just an incredible collection,
thanks for all
daniel from france

hello
I find this set today.
Could someone tel me the voltage and amp i must have for work with this set ?
Thanks for all
daniel from France

https://i58.servimg.com/u/f58/17/20/17/25/sam_6338.jpg

https://i58.servimg.com/u/f58/17/20/17/25/sam_6340.jpg

https://i58.servimg.com/u/f58/17/20/17/25/sam_6341.jpg

https://i58.servimg.com/u/f58/17/20/17/25/sam_6342.jpg

Hi Daniel,

The set will operate from either 12 or 24 volts. You need to slide the power unit out of its case and check the position of the switch on the top deck.

If set for 12 volts you can run the set on vibrator (if the vibrator is OK) for receive, and the dynamotor will start on transmit.

If set for 24 volts it will only work on the 'Dyn' position (the vibrator is 12V only).

Before trying it out you need to test (and probably re-form or replace) various capacitors in both set and supply unit to prevent permanent (and expensive) damage.

First, check the fuses fitted to the supply unit. The output (HT1 and HT2) should be 250mA and higher rated fuses must not be fitted they are to protect the dynamotor against short circuits that could destroy the output windings. (The vibrator fuse is 10 amps and is there to protect the vibrator transformer from a 'stuck' vibrator.)

You need to check the following capacitors before applying power:

Power unit.

C32A the large electrolytic on the top deck - this can explode if faulty due to internal pressure build-up.

C105A/B the dual electrolytic next to the vibrator socket.

Set.

C16A - the cathode decoupling capacitor on the 6B8G (V3A). If this has failed (low resistance) there will be no grid bias on the audio output stage, the 6B8G will be turned on very hard indeed, and the audio output transformer (T2A) primary winding will fail. This is a very expensive item to replace.

All the 0.1uF capacitors need checking, but are unlikely to cause damage if power is applied briefly to the set.

Input current: The specification is 7.1 Amps on receive (all on) 10.7 Amps on 'A' set transmit. I assume that's for 12V input and that 24 volt operation will be about half that.

You will have great difficulty running it from a 12V power unit because the dynamotor acts as a short-circuit on start-up and will cause overload trips to operate. It should run on a 24 volt 15 amp supply (mine does). A solution to the start-up current is to connect a 12-volt lead-acid battery in parallel with the AC supply unit output (connect battery to set, then switch on your bench supply before connecting it to the battery in case it does not like voltage on the output terminals when it's switched off), then switch on the WS19 supply unit and check the LT voltage on the set meter. (Check the polarity is correct and that it reads around 12 volts and does not go backwards!)

(If the dynamotor runs slowly and draws about 20 amps with no load on it, it's faulty (short-circuit armature) and you need to get another dynamotor.)

Hope this is some help,

Chris.
(I wrote a long article for the WS19 (UK) group on the Canadian Supply Unit No.2, should I dig it out and re-post it here?)

hello
thanks for all your explications.
I'm looking what i can do !
Kind regards
daniel from france