Wireless Set No. 52 Canadian - Project

[David Dunlop]

A few more things are now out of the way today.

First off, I removed the mounting screws for the two PA TUNING COUNTERS. It was again interesting to notice, with this type of work, the number of screws one finds that have clearly been serviced at some point and they are missing their lock washers.

In any event, when the last screw came out of both COUNTERS, they both rotated very so slightly in a counter clockwise direction. You can just see the lower left side screw holes are now slightly blocked by the mounting plate of the front of each COUNTERS. Nothing a round wooden toothpick cannot realign when the front panel is ready to go back on.

David

[David Dunlop]

The second bit of work was removing the three 1/2-inch hex nuts and internal lock washers from the three switch assemblies along the lower right portion of the panel. I found a box head spanner gave the best support on the hex nuts for this work.


David

[David Dunlop]

This last bit of activity was more of an in depth study than actual physical work. I shall attempt that work tomorrow morning when my head is clear.

I was suspicious some time ago that the Power Selector Switch for MED, LOW and HIGH Power that is mounted directly above the LOCKS, Panel, looked very much like the Selector Switch on the front of the Canadian Wireless Set No. 19 Mk III Supply Unit No. 2. I took a look through the Parts Manuals for both sets this evening and indeed it is: SWITCHES, Toggle, 4-pole, 3-position ZA/CAN 0178.

What struck me as odd when I got my first live look at the 52-Set Sender, was the fact the SWITCHES, Toggle was set so far back from the rear side of the front panel. Only about half of the toggle lever actually sticks out from the panel. Eventually all cylinders started firing and I realized two key things. First, space was needed behind the panel for the lock slide to move up and block the toggle lever from reaching its lowermost, HIGH, power position. Second, the front mounting plate on the SWITCHES, Toggle was designed for a flush fit behind a wireless panel. Point One does not allow this, nor does the fact the LOCKS, Panel occupies the position where the lower mounting screw for the SWITCHES, Toggle would go on the Sender front panel. The work around for this by the Canadian Marconi Company Engineers is rather interesting.

A set of three cylindrical spacers was employed, along with a small, rectangular adapter plate, thereby keeping the switch and the lock unmodified.

In the last photo you can see two long spacers closest to the camera at the bottom of the Sender. These allow the two mounting screws for the lock to pass down and through the adapter plate. Between these two spacers you can see the thin line of the bottom edge of the mounting plate for the switch, with the square lock nut spot welded to it. Normally, the lower mounting screw for the switch would come in from the front of the plate and into the square nut. In this case, the mounting screw comes in through the adapter plate at the back and then into the square nut.

In the background and to the right of the lower right spacer, you can see the smaller spacer that is used for the upper mounting hole of the switch assembly. The upper spacer is shorter than the lower two to keep a constant gap between the rear of the Sender front panel and the switch mounting plate. It will be an interesting exercise getting that shorter upper spacer back in place when it comes time for reassembly.


David

[David Dunlop]

Removal of the LOCKS, Panel and SWITCHES, Toggle combination this morning went rather smoothly.

I started with the bottom pair of LOCKS mounting screws by placing a 5/16 –inch socket on the underside hex nut and a screwdriver in the machine screw head to hold the screw. Then turned the socket until the hex nut was loose, Switched from the socket to pinkies to hold the nut and removed the machine screw by hand as well. When both machine screws had been removed, the LOCKS assembly was still snug against the back of the Sender front panel.

Next step was to use a screwdriver to gently loosen the top SWITCHES mounting screw about three turns. This relaxed the entire assembly enough I could use a pair of tweezers to remove the lower two mounting spacers. I then carefully removed the top machine screw by hand.

At this point, the lower end of the LOCKS and SWITCHES drops noticeably but not enough to extract the LOCKS. About one inch of swing is needed to allow the lock cylinder to drop far enough it can pivot free from the panel. It is prevented from doing that because of the mass of switch wiring the assembly now rests on at the top end of the switch back.

To get the clearance needed for the lock cylinder to swing free, the switch toggle needs to be able to drop free from its panel hole and move towards the panel hole for the cylinder. I put my two index fingers either side of the switch plate close to the toggle and applied enough downward pressure that I could see a gap open between the back of the Sender panel and the top of the rear spacer. I then reached in with the tweezers and pulled out the rear spacer. A little more angled downward pressure was applied to the switch plate and the toggle dropped free of its hole and moved down the back of the panel enough the LOCKS dropped free and could be removed. The tip of the switch toggle came to rest just at the top lip of the cylinder hole.

I gave the LOCKS a quick wipe to clean off the 3 in 1 oil I had applied to keep the cylinder and slide free. I thought I might find the model number or key code stamped on the body of the lock somewhere but it appears the only visible marking so far is a small horizontal oval stamped roughly centred between the two mounting holes on the back of the lock body with “CORBIN” inside the oval. I will take a closer look at that later. Also on the backside on the lock mounting holes, you can just see the small recess at each hole where the top ends of the spacers drop.


David

[David Dunlop]

With the LOCKS, Panel and SWITCHES, Toggle assemblies both safely out of the way now, I can count 25 (including one broken one and one missing one) likely candidates for being panel screws holding the Sender front panel to the main chassis frame and/or sub chassis panels.

I have a piece of HD foam insulation available which is a little smaller in size than the front panel plate and I will be using that to fasten the panel screw into as I remove them. I have never been one to dump all the screws from something in a big pile and randomly stuff them back in wherever when I have finished working on something. It may take a little longer to organize this approach, but nobody is paying me by the hour to do the work and I know if a screw is going back into a hole it came out of easily, it should go back in just as easily.


David

[David Dunlop]

This Sender seems to give up its mysteries just as readily as revealing new ones to sort out. After careful removal of the 25 panel screws I had previously identified, the front panel was still firmly secured across the mid-section of the chassis. It was then that I realized the upper corners of the Flick Drive Assembly Boxes are also secured to the front panel. By the same screws that serve as the setscrews for the PLATES, Stop, No. 1. In realizing that, it suddenly made sense why the sixth such PLATES, although not installed at the far right side of the panel, still needed the lone setscrew fitted. That mystery now solved, but I still need to sort out why the PA TUNE only required the one, left hand PLATES.

Once those six screws were removed and secured, the Sender front panel lifted clear of the chassis. As usual, several panel screws are missing lock washers and one for certain is oversize. Several are also longer than they need to be. I suspect if any were damaged at some point, the easiest replacement was used rather than getting the proper length. Note to self to find appropriate replacement screws for reassembly.

The two INDICATORS are top heavy when freed from the front panel and swing on the gearbox as a result. I think it should be fairly easy to get the left one set to ‘0000’ prior to putting everything back together.

The really good news was with the middle Flick Drive Assembly. The retaining spring for the two Flick Arms had indeed disconnected from the Lower Arm and as a result, the Lower Arm had fallen away from the Flick Control Shaft. You can see the Lower Arm lying above the shaft in the second photo.

The paint on the right hand Flick Drive Indicator Flags is factory original and in very good shape. When exposed to light for a while and then put into darkness, the upper white sections of the two flags glows bright green. The white on the other two sets of flags has been painted over at some point with a plain flat white paint that did not adhere well to the underlying luminous paint. It has all blistered and lifted. In the dark, only the outer edges still show a slight glow and you can see where the newer paint was applied in large gobs with a brush. I now have a supply of the correct luminous paint so these two sets of flags will get a repaint.

Pretty good access overall for getting at internal chassis components fro a good cleaning now.

Have to take a closer look at the broken panel screw on the right side upper chassis rail now as well, to see how best to remove it.

David

[David Dunlop]

I have been taking a closer look at the panel mounting hardware on this Sender. A two-part reason for this.

Firstly, I want to know exactly what it is I have on this Sender, and secondly, once knowing that, I want to try and determine what is correct and what is not.

I started by numbering all 31 screws I had removed, on the foam board I transferred them to, and then I spec’d each of them out and recorded the data obtained. Apart from seven specialty screws, all others were 6 – 32 thread cutting of ¼, 5/16. 3/8 or ½ inch lengths.

I made some inquiries about possible specific names for thread cutting screws, in the process of which I stumbled across references to SEMS Fasteners. When I looked these fasteners up on line, it turns out pretty much any screw or bolt can become a SEMS Fastener. This fasteners claim to fame is the fact the shank of the screw, directly under the screw, or bolt, head is machined down slightly thinner than the following thread. A split washer is then fitted in that space and essentially held captive there.

With the exception of the previously mentioned specialty screws and two other in the panel, this type of fastener was what was being used as the panel mounting hardware. When I went into the Hardware Listing for the 52-Set, I found them listed as SEMS Fasteners. The big advantage of this hardware on an assembly line is the amount of time saved at stations where the workers do not have to fit individual screws and washers together before installing them. Both pieces are automatically together.

The other interesting thing in the Hardware Listing was that only two lengths of 6 – 32 SEMS Fasteners were used installing the front panels: 5/16 and 3/8 inch. So the ¼ and ½ inch ones I have present are clearly substitutes. That is a big help at this point.

David