Wireless Set No. 52 Canadian - Project

[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

[Lynn Eades]

Hi David, going back to post #664. Are you aware that you can edit any post you put up?

[David Dunlop]

Good Evening, Lynn.

Yes I was aware of the feature and have used it on many postings whenever the AI decides to run amuck grammatically.

I chose to leave things as is for the time being as there are more mysteries surrounding the Canadian Wireless Tent, than clear answers. At the moment, the PINS I have on hand, and a wooden mallet used to set the pins, are the only two items to be found in the VAOS and Tentage Listings published through the 1940’s and 1950’s. British and Indian tents show up but not the Canadian one.

I will probably revisit the mystery again , down the road, once I have the 52-Set back up and running.

Cheers,

David

[David Dunlop]

A somewhat stressful but positively productive day today so far.

As per the attached photos, I was able to remove the Sharp/Flat Switch Knob and release the switch from the chassis with no problem. It then hung quite nicely below the Coil Assembly I needed to work on. The six retaining screws for the Coil Assembly came out very easily, probably because they had been loosened up a bit when the two Coil Assemblies were upgraded. By comparison, there was a lot of factory, original varnish on the two mounting screws for the Sharp/Flat Switch and it took a careful increase in turning the screwdriver to pop them free.

The Coil Assembly I had to work on slid out quite easily with the anticipated resistance as the sleeves on the Rotator Terminal strips rubbed the edges of the holes. It was easy enough to give them a gentle squeeze with one hand while guiding the Coil Assembly free with the other.

I stacked some 2 x 4 bits up on the bench and topped them off with a portable bench vice at a height the Coil Assembly could rest against once free of the rear chassis wall. This left it at a nice working angle, leaving both hands free to attend to the necessary details.

You can see how wide open the gaps are between the capacitor plates after the spring tension released when the retaining nut broke, jamming them against each other. I then cut the two connecting leads to the Trimmer Cap free at the upper coil terminal ends. I then removed the two mounting screws holding the dead Trimmer Cap in place and that’s when things got a bit interesting.

I could not remove the old capacitor from the Coil Assembly. It should have simply lifted right off and away, but was getting hung up on something. It took a few worrisome moments to realize that when the rotator plate broke free from its tension spring, so did its related terminal post that normally sat on the left side of the Trimmer Cap. It had now swung back under the coil-mounting frame and was preventing the Trimmer Cap from lifting out. Once I realized what the problem was and sorted out how to get my left pinkie finger on the errant terminal, I was able to move it back to where it needed to be to lift the old Trimmer Cap free.

After that, the replacement Trimmer Cap went in quite easily and I was able to get the two leads I had installed on it earlier soldered in place quickly. It was then simply a case of reversing the disassembly steps to put all back in place.

The last photo shows the Coil Assembly remounted, the three individual wires resoldered and the Sharp/Flat Switch back in place. This evening I will resolder the Grid Cap Clip and Sleeve on the V1D Grid Cap Lead, tie the sleeve in place to protect the lead from the sharp edges of the V1D Shield Cap and fire the receiver back up to see if there are any noticeable improvements in performance so far.

Hopefully next weekend I can then get the receiver back over to my friend’s workshop where we can finish tweaking it back to life,


David

[David Dunlop]

I have now carefully brushed the loose dirt from the six remaining PINS, cleaned them all with Lemon Oil and given them two light coats of Boiled Linseed Oil, drying 48 hours between each coast and wiping any excess off, one half hour after application to prevent any surface sticky residue buildup.

I then took a sufficient length of new Jute Twine to give them the same double wrap and triple knot binding as the factory original set. there is a 1-1/4 inch loop tied off with a double knot on the originals where an ID Tag would have been fitted. I am leaving that open at the moment while I sort out the details of the tag. There are some bits of equipment hiding here somewhere with these tags on them, but no rush for the moment.

Surprising how close to the originals these cleaned up ones are when finished.

David

[David Dunlop]

The Grid Cap Clip has now been resoldered in place for Valve V1D, the protective sleeve slid back over the connection and a new lace tied over it and lacquered down.

With the receiver top panel back in place, I hooked the receiver up to the Remote Supply and turned it on. BIG Happy Dance The built in Crystal Calibrator came booming in all the way from 1.75 MC to 8.0 MC through Bands 1 and 2. I had to really back the volume off. Prior to this, with AF and RF Gain full on I could barely hear the calibrator signal which completely disappeared around 4.5 MC. The receiver is still not detecting the calibrator signal from 7.0 to 16 MC on Band 3, but a 66% improvement in this area so far is a huge improvement.

In RT Mode and connected to my dipole aerial outside, reception conditions were not great tonight, but I picked up the WWV Time Signal at 5.0 MC with no problem and could just find it drifting in and out at 2.5 MC. Quite pleased with where its at so far and hopefully another session in my friends workshop will have the rest sorted soon enough.

David