Wireless Set No. 52 Canadian - Project

[David Dunlop]

I know what you mean, Bruce. There used to be two huge fabric stores here in Winnipeg that my Grandmother used to shop at between the Wars. I was able to find the Olive Green Oil Cloth in them that was used on Universal Carrier Seats back in the 1980's. As of 15 years ago, both are gone. Furniture Upholstery Shops that used to fill a page of the phone book are down to a handful today.

I found the Jute twine at a Peavey Mart which opened in our neighbourhood about 3 years ago. Kind of a Canadian Tire for the rural agricultural community but they carry some very useful products you never find in the 'big city stores' any longer.

David

[David Dunlop]

I was able to get new leads installed on the replacement Trimmer Capacitor this morning.

Of course, as carefully as I had thought the process out, I ended up modifying on the fly somewhat. But pre-thinking the steps out still helps overall.

What I found was that the amount of factory applied solder to both terminals I was dealing with on the C7D Capacitor was massive and I had no choice but to VERY carefully melt it away. I ended up with two dime sized blobs on the top of the work bench. Even with that done, there was no way I could get rid of the wire wrap still left on the terminal at the top of the right hand Stator Plate Post. I finally realized the left side post was virtually unused and new and both were part of one and the same circuit in the capacitor. So I ended up cutting a lead long enough to solder to the left terminal and shape over to the right to line up with where it will have to go when installed in the coil assembly.

By comparison, the second lead attached to the Rotator Plate terminal on the extreme left, was a piece of cake.

The two photos show the pair of new leads freshly installed with red lacquer over the soldered connections and with the original insulating sleeve for the Rotator Plate terminal slipped back in place.

So now I can 'relax' until the weekend and start the more serious part of this replacement process, fully aware there are going to be some surprises, regardless of the amount of planning I do.

David

[David Dunlop]

The process of replacing the C7D Trimmer Cap in the Main Set Receiver has now begun. I have lost track of the number of steps I expect this Sub-Project to take, as I keep breaking it down into smaller, more easily accomplished sections.

The first bit of work requires careful removal of the V1D Valve, Grid Cap Clip, avoiding any cockups.

The attached photos show this Clip in place and disconnected from the Grid Cap. The small, black sleeve covering the soldered end of the Clip has been slid out of the way, for purposes of desoldering the lead/clip connection. Interestingly, this particular sleeve was not tied in place. I will have to remember to do that when it is time to slide it back in place.

The clips themselves are quite delicate, and can crush easily. I need to apply a certain amount of tension to the clip lead while desoldering for the clip to slide off the end of the lead. The ID of the clip is not wide enough for a pencil to fit in it, but one of the modified wooden chopsticks I was using for spray painting some of the smaller parts on the Sender will work just fine.

I will post more pictures once the Grid Cap Clip is free. If I don’t post for a while, then I have gone to the Pub for some reason…


David

[David Dunlop]

I am still alive and sober!

The work on removing the V1D Grid Cap went pretty much as planned this morning with just one, improvised on the fly modification to the steps I had in mind.

As per the attached photos today, the Grid Cap pulled free easily when the soldering iron heated up the joint. Interestingly, the Grid Cap had a crimp fixture on the end of it that was not used. The lead was originally just laid on and soldered down.

With the Grid Cap and Sleeve safely out of the way, the next step was to join a 6-inch hook up wire extension to the grid Cap lead to allow for its retrieval from out of the Coil Assembly Shield, after the C7D Trimmer Cap was replaced. It was here the improvising took place. There was no working surface available to provide resistance or stability to the two pieces of wire that had to be soldered together. So I found a small strip of ¼-inch plywood and slipped it across the front section of the chassis under the two wires. I then lined the two wire ends up, one under the other and taped them in place. A touch of the soldering iron and a dab of solder and ‘done’.

My main point of concern with this step overall, was that the temporary extension of the Grid Cap lead was strong, and small enough to pass through the metal sleeve grommet in the hole on the top of the Coil Assembly Shield.

I took one of the spare Shields from the Spare Parts Receiver and tested putting the grid cap lead through it. A very slight resistance and the loom of the main wire passed in and out but all checked out just fine.

Next step will be to unsolder the three Coil Assembly leads needed to free up as much manoeuvring room behind the chassis as possible.

David

[David Dunlop]

For some reason I missed this little detail when dealing with these Grid Cap Clips on the Spare Parts Receiver.

The outer circumference of these clips has the following information stamped into them:

NATIONAL
GRID-CAP
MALDEN, MASS.
PAT. PEND.

David

[David Dunlop]

As noted a couple of Posts back, the next Step in the C7D Trimmer Cap replacement is to free up the three individual leads coming out of the mid point in the relevant Coil Assembly, to maximize the movement of the Coil Assembly, once free of the rear chassis plate of the receiver.

In the attached photo, these three leads are:

- The big long one heading up to the Pin on the V1C Holder. Valve V1C is the Mixer and this Pin is either numbered ‘6’ in the Canadian Numbering System, or ‘7” in the British Numbering System.
- The medium length lead running to the bottom terminal of the front capacitor C3T on Tag Board DR, immediately to the left of the Coil Assembly. This capacitor is the A.V.C. Decoupling cap.
- The short lead running to the lower terminal of the Tag Strip 1-Way mounted to the left side of the Coil Assembly.

Interestingly, all three of these soldering points show earlier, rather sloppy, soldering work, probably done at 202 Workshop when the two Coil Assemblies in this receiver were upgraded from the factory originals.

A closer look at all the connections on the Sharp/Flat Switch shows the same work having been done.

David

[David Dunlop]

The three individual Coil Assembly leads at the back of the receiver have now been disconnected.

When I looked at the V1C Pin the longest lead had been connected to afterwards, it seemed bent back somewhat and it had a large blob of old solder stuck to it that appeared as is it could be a path to ground, so I put the soldering iron on it and pulled a drop of solder off, the size of a BB pellet. I also returned the Pin to a more vertical position. Better to be safe than sorry.

Tomorrow will be an ‘Errands Morning’, but I hope to next get the Sharp/Flat Switch Knob removed from the front of the receiver and the two mounting screws for this switch removed so I can free the switch assembly up and see how much free play I might be able to gain on the Coil Assembly main harness.

I will be thinking ‘happy thoughts’ tonight.

David