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  #91  
Old 10-09-18, 00:22
Chris Suslowicz Chris Suslowicz is offline
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Originally Posted by David Dunlop View Post
While I think of it, has anyone had experience disassembling the large Bakelite Connector Sockets on this equipment? It is hanging down with the supply plug attached to it in the last photo, but a better view is in Post #28 of this thread.

One of the contacts had been broken off on this Remote Receiver, and there is a large relay mounted on the back of it that would have to be unscrewed. I am curious if replacing the broken contact would be a purely mechanical process or if a soldering iron is required. A large, heavy duty terminal strip runs along the inside lower end of the socket that likely feeds to the individual contacts. My guess is these contacts are probably mounted via screws to their respective terminals.

David
It's easier than you think (probably). All the connectors are identical bakelite mouldings and the contacts are fitted 'as required'. the connector body is attached to the chassis by two screws from the rear (between the rows of contacts) which go into threaded brass inserts in the bakelite moulding, and the contacts are fitted from the front with a lock washer, tag, and nut on the rear, then the nut is sealed with varnish to prevent it working loose. (Do NOT try unscrewing the contact from the front, you will just deform the contact and possibly shear the screw head off.) The 'terminals' are actually tags; short straight ones for the contacts on the bottom row, and longer 'L' shaped ones for the top row. They fit into grooves in the bakelite moulding so that they cannot move sideways. You'll need a thin, broad-bladed screwdriver for the contact side, and a box spanner or nut driver for the terminal side. The screw slot is in line with the slot in the contact and the screwdriver is used to hold it in place while you attack the nut on the back. I'd advise softening the varnish with something (Acetone?) before attempting to undo the nut. (Of course, if the contact is missing because the screw is broken, you may just be able to withdraw the broken screw with nut attached and fit a new contact fairly easily.)

I have your valve holders / tube sockets and will include a scrap WS52 connector that you can use for parts. Hopefully this week if I can get to the Post Office.

Chris.
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  #92  
Old 10-09-18, 17:10
David Dunlop David Dunlop is offline
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Thanks for that, Chris. Let me know the postage and I will send it off to you.

The spare connector may come in very handy. The broken connection behind the connector socket assembly was one of the Aerial Circuit Relay terminals and that relay is inactive normally in the Remote Receiver. Good to now have it reconnected though and the free wire out of any future harms way all the same.

However, (Interesting how that word can pop up so often in restoration work), once the connector socket assembly was remounted to the chassis and power reapplied, I no longer have +12 V anywhere in the system and no +150 V showing on HT Mode on the meter. Every valve is stone cold inactive.

I switched the Remote Supply to my backup receiver and that receiver lit up straight away. All voltages normal and the meter shows about half the valves with normal readings, the remainder with nil readout. While hooked up, I took readings from the terminal strips on the back of the connector socket. The HT was 155.5 V with the meter showing spot on 150 V. The LT reading at the connector terminal was 2.39 V. Struck me as a bit low but all items downstream from there on the LT side were responding correctly.

Back to the Remote Receiver chassis to check the same two connector socket voltage values. The HT terminal came in at 218.5 V. This is very close to the raw output HT from the Remote Supply. The LT reading was 0.75 V.

What initially comes to mind is a short in the system and with the missing contact on the connector socket, I am wondering if the screw stub and/or nut inside may finally have broken free and moved into contact with internal circuits. I briefly had a working system when I first jumpered the broken relay wire behind the connector socket assembly. Maybe all the jostling about of the socket assembly while resoldering bumped the broken hardware free inside to run amok.

Sigh!

David
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  #93  
Old 10-09-18, 20:28
Chris Suslowicz Chris Suslowicz is offline
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Quote:
Originally Posted by David Dunlop View Post

However, (Interesting how that word can pop up so often in restoration work), once the connector socket assembly was remounted to the chassis and power reapplied, I no longer have +12 V anywhere in the system and no +150 V showing on HT Mode on the meter. Every valve is stone cold inactive.

I switched the Remote Supply to my backup receiver and that receiver lit up straight away. All voltages normal and the meter shows about half the valves with normal readings, the remainder with nil readout. While hooked up, I took readings from the terminal strips on the back of the connector socket. The HT was 155.5 V with the meter showing spot on 150 V. The LT reading at the connector terminal was 2.39 V. Struck me as a bit low but all items downstream from there on the LT side were responding correctly.

Back to the Remote Receiver chassis to check the same two connector socket voltage values. The HT terminal came in at 218.5 V. This is very close to the raw output HT from the Remote Supply. The LT reading was 0.75 V.

What initially comes to mind is a short in the system and with the missing contact on the connector socket, I am wondering if the screw stub and/or nut inside may finally have broken free and moved into contact with internal circuits. I briefly had a working system when I first jumpered the broken relay wire behind the connector socket assembly. Maybe all the jostling about of the socket assembly while resoldering bumped the broken hardware free inside to run amok.

Sigh!

David
What you've got there is no heater supply, so there's no load on the HT. The very low heater voltage could be due to a short circuit (loose bit of metal in the back of the connector, shorting something to ground), or to a high resistance (dry) soldered joint in the LT circuit.

You could remove all the valves and measure the resistance between +12V and chassis - with no valves fitted it should be very high resistance (or open circuit).

If it is a short circuit, don't risk the power supply by running it for more than a few seconds - I don't think there are any fuses in the LT circuit, and it will overload the transformer.

Chris.
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  #94  
Old 10-09-18, 21:52
David Dunlop David Dunlop is offline
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Hi Chris. I initially thought a short might have been in one of the AF Amp valves, so pulled them to see what happened. Nothing, so decided to pull all of them with no ultimate change. That had me leaning towards the absence of B+ creating the inactive valves, resulting in the HT electrons with nothing meaningful to do. Thanks for the confirmation I was on the right track.

After you mentioned it, I realized I had checked the 12 V terminal to chassis and got a very high value. My brain must have been in ‘volts mode’ and did not make the connection to the fact that particular test had been resistance related, and what the result actually meant.

I’m hoping that a disassembly of the connector socket will reveal loose hardware bits floating about inside, and solve the problem.

A previous owner of this Remote Receiver had drilled holes in the rear of the case to mount a modern Coax Aerial Socket. Have since discovered this was done with liberal application of cutting oil and with the receiver chassis still in place. The bottom back edge of the case was wet with oil and metal chips stuck in it. Spent a while cleaning it all up and also found the same crude sitting in the bottom lip of the rear chassis. Visually, the lower chassis floor looked OK but when I pulled the V1G and V1H valves, I found a sweat of oil between the sockets and valve bases. More cleaning done there as a result and another reinspection.

David
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  #95  
Old 12-09-18, 16:41
David Dunlop David Dunlop is offline
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Default 52-Set Electroplating

Thought I would take a break here to poll the collective wisdom of the MLU Group.

I will start by referencing back to Page 2 of this thread, Post #46, Photo 3. This is an interior shot of the ZE-11 Remote Supply cover. Of interest here is the nature of the interior finish that is visible.

My first thought was this finish was just another metallic looking paint, although what stood out with it was the extremely fine metallic powder that must have been used to make it. it does not look at all like the typical aluminum finish paints available today. Curiosity got the better of me eventually and I tested the surface of the finish with a multimeter and was very surprised to see how conductive it was. A closer inspection of the Remote Supply revealed the entire cover assembly AND the base assembly had this coating under the paint.

A closer look at the Remote Receiver Case revealed it too had a complete coating of this finish on it, covering the entire finished assembly, with the exception of the Grounding Post Screw on the lower rear right side. The finish paint was then applied to the case, reaching into it only two inches from the leading edge of the case. I have yet to see one in person, but strongly suspect the entire basic, sheet metal case assembly of the Carrier No. 4 for the 52-Set is also finished in this coating. The heavier metal parts of the Carrier Assembly, possibly not.

I am pretty certain this is an electroplated finish and have narrowed the possibilities down to three metals: cadmium, satin nickel and zinc. I am presently leaning towards the satin nickel finish. From what I have seen of 75 year old cadmium and zinc plated items, somewhere, to some degree, one can find traces of humidity induced oxidation of the metal. The finish on these 52-Set items is pristine.

Once the dust settles with the new school term at the University of Manitoba, I would like to take the Remote Supply cover over to their Chemistry Department and see if they might have a none destructive means of testing this finish to determine what metal it is. I will need to know since several holes drilled into the back of my Remote Receiver case will need to be repaired and I would like to then have the case replated to completely restore the original look before painting.

I have run across a few references to satin nickel plating being used on wartime electronic items intended for navy use and shiny nickel pated finishes show up quite regularly on valve covers in army equipment. Has anyone encountered written references to the use of a satin nickel electroplating on components of wartime wireless gear?

David
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  #96  
Old 22-09-18, 01:03
David Dunlop David Dunlop is offline
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Iíve been looking at the Master Parts List for the 52-Set, with regards to the five large rectangular electrical Plug and Socket assemblies. All are listed as replacement items, as complete assemblies. In spite of the fact they can be disassembled for repair, the only individual part that is separately listed is the Leaf Type Connector contacts for the socket assemblies. The Blade Type Connectors for the plug assemblies, is oddly not listed separately.

Now I wonder if these Plug and Socket assemblies are covered in more detail in the Parts Lists for other wireless equipment manufactured by Canadian Marconi?

David
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  #97  
Old 23-09-18, 16:16
David Dunlop David Dunlop is offline
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Further to the quest for information on the large rectangular bakelite 8-Pin Connector Plugs and Sockets on the 52-Set (as per Posts 28 and 35), can anyone with an original British made Wireless Set No. 9 confirm if these same connectors were used in the manufacture of the British No. 9 Sets? This may help trace the origin of these connectors.

David
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  #98  
Old 26-09-18, 19:47
Bruce MacMillan Bruce MacMillan is offline
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I don't have access to a Canadian WS9 anymore but the schematic shows a similar style of connector as the WS52.

CMC only built the receiver for the WS9, the xmtr being built by Northern Electric. That would suggest that there was a third party manufacturer or somebody shared the product. Both companies had the capability to produce them.
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  #99  
Old 27-09-18, 00:00
David Dunlop David Dunlop is offline
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Thatís interesting news, Bruce. I was not aware of that production sharing for the Canadian Wireless Set No. 9.

There is an illustrated parts list on the British Royal Signals site for the Canadian No.9 Set I have requested a copy of, so will see what it shows for looks and nomenclature, compared to the 52-Set Cdn for these connectors. Then, with some luck we might be able to push the references back to what STC in England was doing.

David
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  #100  
Old 27-09-18, 01:17
Chris Suslowicz Chris Suslowicz is offline
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Quote:
Originally Posted by Bruce MacMillan View Post
I don't have access to a Canadian WS9 anymore but the schematic shows a similar style of connector as the WS52.

CMC only built the receiver for the WS9, the xmtr being built by Northern Electric. That would suggest that there was a third party manufacturer or somebody shared the product. Both companies had the capability to produce them.
Given that the remote receiver was usable as a spare for the set receiver, and that the WS52 and WS9 remote receiver power cables are virtually interchangeable, I'd say the connectors are identical in construction, if possibly different in pin configuration. Whether they're an exact copy of the ones used in the STC-built WS9 is another matter, but I would not be surprised to find that they were.

Chris.
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  #101  
Old 28-09-18, 00:09
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Tim Bell Tim Bell is offline
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Chris

You are welcome to inspect my Canadian Ws9 anytime.

Cheers

Tim
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  #102  
Old 30-09-18, 03:24
David Dunlop David Dunlop is offline
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Finally got back to some thinking about the potential short in my Main Set Receiver Connector Socket this past week. In particular, the fact that I had noticed when connecting the Remote Supply Connector Plug to the socket, the retaining screw did not seem to run home as far as it did when I connected this cable to my backup receiver. That in turn got me wondering it this screw might be jamming on some loose bits inside and perhaps be part of the short problem.

Add to that, I was curious if it might be possible to isolate if the short was in the 12 Volt LT circuit, or the 150 Volt HT circuit. So I dug out my trusty old 2 Amp 12 Volt DC Trickle Battery Charger to jumper onto the 12 Volt circuit and see what happens.

I first tested the charger output. It was producing 11.78 Volts DC, along with 6.69 Volts of AC. I first jumpered it to the +12Volt terminal on the backup receiver socket and negative to chassis ground. The panel indicator lamp on the backup receiver lit straight away and I got a reading on the meter of 8 Volts DC LT. Turned on the calibrater and its indicator lamp lit and the meter reading dropped to 7 Volts and held. I waited a minute, switched off the calibrator and the meter went back up to 8 Volts and held.

I then switched the charger over to the Remote Receiver and jumpered it up in the same manner. The results were virtually identical to the backup receiver.

I am pleased with those results. Next, I am basically going to repeat this test with the Remote Supply, using jumper cables for both the 12 Volt LT and 150 Volt HT circuits. Basically bypassing the physical connection of the Remote Supply Connector Cable to the receivers. Hopefully that will provide some further useful information.

And while I was mucking about with the Connector Socket on the back of the backup receiver, I noticed the long paper label that runs across the middle of it with the Terminal IDs printed on it was missing. A closer look in that area revealed a cast oval mark with 'CMC' in the middle of it, about one third of the way in from one end. Photo attached. Pleased to finally find one of these marks and hope to find more as the project progresses.

David
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52-Set Receiver Connector Socket CMC Logo.JPG  
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  #103  
Old 01-10-18, 17:00
David Dunlop David Dunlop is offline
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I did the jumpered test of the Remote Supply to the Remote Receiver late yesterday and the receiver lit up beautifully. After about a 10 minute warmup, I took meter readings for the valves. All registered and 'look' to be in the right range of values, but to be sure, I sent a copy of the recorded values to a friend in Arizona who operates a 52-Set Cdn on the air on a regular basis to see how my readings compare to his receiver.

The audio seemed a bit higher in white noise than it should and part of that may be some oxide build up on the various control contacts from lack of use over the years. The audio from the crystal calibrator was a bit weak but the 1000, 100 and 10 Kc pips could all be heard.

The only fly in the ointment was a nil reading for HT on the meter. Likely suspect is the R58A resistor (or resistor pair as it turns out) may have gone South. Now if I can only figure out where the heck they hid the little sucker(s) on the chassis, I can test them and see how close I get to the rated 600,000 Ohm value.

At least I have narrowed the short down to being intermittent and internal to the connector socket. It's nice to make progress on issues.

David
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  #104  
Old 03-10-18, 14:33
David Dunlop David Dunlop is offline
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I had the Remote Receiver setup up and running again last evening for about half an hour. I will probably do this for the next week or so to give all the little bits a chance to get used to electrons moving about again, and also give me an opportunity to work switches and dials mechanically. I did notice the tuning dial has a small arc of stiffness at one point, so will eventually get around to disassembling it for a cleaning. Nice that they are identical mechanically to the 19-Set ones.

I hooked the receiver up to my dipole last night as well and was able to find WWV in Ft. Collins quite easily at 5.00Kc. The signal drifted in and out quite a bit and there was a lot of crud jumping all over it, but it was there. Some of that crud may, in fact, be some weak tubes in the set, but HF propagation recently has been quite bad as well.

David

Last edited by David Dunlop; 04-10-18 at 01:08.
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  #105  
Old 08-10-18, 21:20
David Dunlop David Dunlop is offline
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I have been running the Remote Receiver each evening for a week now, between 30 minutes and an hour each time.

The valve readings from the meter have stayed very close to those initially recorded when I first fired the receiver up. The background noise seems to have dropped off a bit on the loudspeaker when listening to the WWV Time Signal and this is still all with the RF Gain at 'maximum' and the AF Gain at very close to maximum. The crystal calibrator pips are still somewhat buried in the background noise.

I decided to add another test to the mix on the weekend by checking out my Receivers, Headgear, MC, Mk.1 in both PHONES sockets. I figured this would tell me what both sockets were up to, that the Receivers Headgear worked and that the toggle switch between the loudspeaker and the headgear also functioned properly. Pleased to report all items responded correctly, but one point did surface I am curious about.

This is the first ever wartime wireless set I have ever worked on/listened to that is equipped with an installed loudspeaker. What I noticed straight away was the level of background noise seemed much greater via the loudspeaker circuit than the headgear circuit. I had to back off the RF Gain nearly 1/4 from full maximum and the AF Gain by about 20 % from where these two controls were set for the loudspeaker, when I was listening to the set via the headgear. I also noticed that through the headgear, the crystal calibrator signal was very clear at all three positions compared to when listening with the loudspeaker. The speaker is identified as:

LOUDSPEAKERS, 3-in, PM, 3.5 Ohms

Now it is still quite possible that some of the valves are not fully up to standard and this may be influencing the level of background noise I am experiencing, but can anyone advise if, in general, it would be expected for a wartime era loudspeaker in a wireless set to have a noisier output than a set of headgear?

David
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  #106  
Old 13-10-18, 19:39
David Dunlop David Dunlop is offline
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At this point, some of you might be interested in what the 52-Set Remote Receiver setup looks like powered up, so here are a couple of photographs of the receiver warming up on it's own, and with the Crystal Calibrator also warming up.

Nice to see the red indicator lamps finally glowing. I cannot help wonder when that last happened.


David
Attached Thumbnails
WS No. 52 Remote Receiver Powered Up.JPG   WS No. 52 Remote Receiver Powered Up 2.JPG  
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  #107  
Old 14-10-18, 18:27
Bruce MacMillan Bruce MacMillan is offline
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A sight to see emitting only photons and not smoke.

Nice set, winter is coming, maybe a qso across the pond.
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