Wireless Set No. 52 Canadian - Project

[David Dunlop]

Work on the receivers is now on hold, pending arrival of a supply of needed spare valves, so I am switching to the Sender, in order to start giving it some much needed TLC. It is a sad looking bit of kit at the moment, but the front panel is going to be the much easier task to undertake, and will have much more visual impact when finished (whenever that turns out to be).

The vast majority of paint chip damage to the Sender has happened around the edges of the panel and in a few spots, I will have to wick glue under the lifting paint to secure it from further damage. I am hoping that once the staining in the varnish has been polished down to the desired patina, the damaged paint around the edges will become less noticeable. The front panel of the Sender is so chocked full of knobs dials, buttons and switches, the eye gets naturally drawn away from the outer edges and the paint chips tend to disappear into the background shadows. The damage is not at the point where it detracts from the Sender and keeping it adds confirmation this 52-Set had a working history.

Apart from the paintwork, this Sender has very little other physical issues discovered so far. The four attached photos cover off what I have found will require some attention, and only one is currently of concern.

The first photo is of roughly the upper right quadrant of the panel. A panel mounting screw has had its head snapped off, directly above the BAND Switch. The screw shaft is exposed behind the chassis, but next to impossible to access to try turning it all the way out. It will likely become a candidate for being carefully drilled out. It is one of those small, split tip self threading items that also shows up in the assemblies of the 19-Set so should be an easy item to find replacements for from some of the bits I have on shelves as spares.

The critical repair also shows up in this photo. It is the COUNTERS, 0/9999, 2-3/4 inch x 1-3/8 inch x 1-7/8 inch, No. C1 ZA/CAN 4642, which is the small, four-digit dial indicator for the 7 – 16 MC PA TUNING assembly. As you can see, the indicator shows ‘0,0,0,4/3’ with the dial brought all the way back to its starting point. It should be showing ‘0,0,0,0’ at this point and I will have to figure out how to zero set it eventually.

The second photo is the upper left quadrant of the panel showing how badly chipped the paint is on the Blower Fan Cover. No way around it, that item will have to be removed, cleaned up and repainted. Way too much bare metal now showing on it.

The third photo is the lower left quadrant and the only thing going on there at the moment is another split type panel screw that is completely missing.

The last photo is the lower right quadrant where the Slow Motion Drive for the PA TUNE dial is missing critical parts, which I now have a suitable temporary replacement.
Another bright note, I have discovered the cabinet lock for blocking High Power Mode on the output power switch, is not frozen. Just need to track down keys for it eventually.


David

[David Dunlop]

This is the formal name for the two four-digit indicator dials on the 52-Set Sender PA LOADING Dials and the Coil, Aerial Tuning Assembly.

As the name of the item notes, these Counters are capable of reading from a Zero start point all the way up to “9,9,9,9”, if they need to. As far as the 52-Set is concerned, none of the three Counters come even close to their limits at their respective top ends.

The error on the 7 – 16 MC PA LOADING Counter on my Sender is high when it is back at its Zero Point. After thinking about it for a while over the evening yesterday, I realized the only way that could have happened was at the top or upper limit of travel for this Counter, but I had no idea exactly where that upper limit would be, for ANY of the three counters used with this wireless set. And none of the manuals reference that limit information either. The only way the misalignment of numbers could have happened, given the design of the system, was if somebody had rapidly spun the dial up in a very aggressive fashion and when the upper stop was hit, the angle drive at the back of the Counters flexed enough for the gear set to jump a few teeth, pushing the numbers up three and a half digits higher than the indicator should have gone.

So I took the time last evening to run each dial up to its upper limits and recorded the results as follows:

7 – 16 MC PA LOADING: 0,4,4,9/8 *
1.75 – 8 PA LOADING: 0,7,7,8
COIL, AERIAL TUNING: 1,2,9,6

* Given this COUNTERS is now reading 3.5 digits high, the correct upper reading should likely be ‘0,4,4,5’


Thought I would post these results in case anyone else needs to know.


David

[David Dunlop]

Here is a photo of the back of the Counters for the 1.75 - 8 PA LOADING Coil. It is the only one in the set that is readily visible at the right side of the Sender Chassis The incorrect one, unfortunately, is inboard of this one and next to impossible to view/access without major disassembly of the Sender.

You get a good idea of how the angle drive operates and relates to the main shaft of the coil assembly, however, and all three would have an identical setup.


David

[David Dunlop]

This little bundle arrived in this afternoon's Post. 12 NOS Canadian Marconi Company (Radiotron) 12Y4 Valves in minty, original wartime packaging.

David

[David Dunlop]

The Sender is now laid out for disassembly and cleaning. I have the back of it resting on two 18 inch sections of 2 x 4 lumber to protect the pair of 8-pin connector sockets on the top rear of the chassis. This keeps them well off the surface of the work desk.

I wish the rest of the chassis interior was as clean as the bottom section. Sigh!


David

[David Dunlop]

I spotted one of these BA Tap and Die Sets on Amazon Canada a couple of weeks back and ordered one. It arrived this afternoon.

It will very likely get put to good use cleaning up threads on various parts of this 52-Set project.

David

[David Dunlop]

There are a couple of rivets used on the 52-Set I need a correct identification for as some of the project work down the road is to replace a couple of parts fastened by them. I think they are either called tube, or hollow rivets and appear to be plated brass in nature.

The first type are illustrated in the first photo of Post #248 and here. They have a shallow truss head and are used to hold the AE Aerial Terminal in place on the Sender.

The second type is a full countersunk head rivet used to mount the fixed receptacles for the cowl head fasteners. the 2nd and 3rd photos are of this style rivet.

David