Wireless Set No. 52 Canadian - Project

[David Dunlop]

All the metal hardware on both cases has been cleaned with the wire wheel and a coat of primer applied.

In reviewing my notes from restoring the tool box a few years ago, I found comments that it would be better to paint all the hardware Flat Olive Drab first, and then apply the colour to the rest of the box/case as the last step. I cannot recall what problem I encountered that prompted that conclusion, but will let the primer cure for a few days now and then give all the hardware an application of Flat Olive Drab.



David

[David Dunlop]

It has been an interesting weekend.

I powered up the 52-Set Friday evening to see what propagation was like and make sure my retuning of WWV from 10.0 MHz for the winter to 5.0 MHz for the summer was still tuned and stable. After the usual 10 to 12 second warmup, I was surprised to hear the merry hum of the vibrator coming from the speaker and no signals of any kind.

The meter was showing the usual LT reading of 11.0 Volts DC (still missing 1.70 Volts) but a quick check of the HT status showed a drop from the usual 130 Volts to just 70 Volts, well under the operating minimum mentioned in the manual. That discovery was followed by a quick shutdown.

Something has been stealing 1.7 Volts of Low Tension and 20 Volts of High Tension from the Receiver from the very start. I know the Vibrator is in great shape and the OZ4A was brand new prior to first starting the Supply Unit up.

Looking at the schematics, the first suspect I will have to look at is the 20 mF “Twins in a Tin” electrolytic filter caps, following a retest of the OZ4A on the Tube Tester. If that cap set checks out OK, the next on the list are two PIO electrolytic caps on the secondary side of the transformer. These are described as ‘Secondary Timing Capacitors’ in the manual. This is something new to me to wrap my head around. No references to such an animal at all in my 1960 and 1970 ARRL Handbooks, though all sorts of information seems to be on the internet with reference to these caps in modern solid state electronics.

Funny how Life always seems to send you a Learning Curve when you least expect it.


David

[David Dunlop]

This item arrived today, a Hickok 209A Multimeter. It is part of the list of test equipment used by the RCEME when servicing the Wireless Set No. 52 Canadian. In this role, it is better known under its Canadian licence built version, manufactured by Stark as the VT9A. These two products are virtually identical electronically and capability wise, differing only slightly in the positioning and identification of a few of the controls on the front panel.

I was very surprised when I discovered it was shipped to me in its original 1947 Hickok shipping box, and even more surprised when I found the Serial Number on the box was a match to the inspection card still attached to the meter and the data plate on the rear panel.

The unfortunate downside to all this, however, was the fact at some point in this meters history, somebody opened up the box and wogged the set of probes issued with the meter, along with the Manual. Still nice to run across an NOS test meter that was 76 years old though. That does not happen every day.

So between now and whenever the 52-Set Project reaches the point where I have to test the medium and high power outputs of the Sender, I can look for the missing probes used with this meter.

Oh, and one other thing, this meter is no light-weight. It measures 16.5” wide, 13.5” high and 8.5” deep and weighs between 15 and 20 pounds.



David

[David Dunlop]

I decided to perform a quick check-up on the Hickok 209A today before getting back to the two Spare Parts Cases.

It only took a few moments to realize this meter was actually not NOS, but a purchase that had been very carefully used and maintained over the years, to the point the purchaser had kept the original shipping box to store the meter in, while not in use. The AC cord originally equipped on the 209A was a rubber cord, 8 feet long, with the name HICKOK cast into the sides of the plug, which was a basic two pin plug. The AC cord presently on the meter is a black plastic one with a polarized plug, only 6 feet in length.

The front panel of this meter is a solid sheet of almost one eighth inch thick aluminum. The case is formed sheet steel with a coat of blue/grey enamel inside and out that has only three small chips on it. The bottom and the back of the case have four feet pressed into the steel and none of them have any trace of wear on the paint at all.

The chassis had the usual accumulation of static dust on the components that brushed away very easily and the clips for the two D-Cells used to power the Resistance function were both empty.

I had a pair of about half power D-Cells on hand that I installed, and I carefully pulled he four valves and ran them through my tube tester. Only V2, the 6X5GT Capacity Voltage Rectifier, failed at 32% on both sides. The other three valves in the chassis came in between 68% and 92%. With no spares on hand, the four original valves went back in for the purposes of live checks of the ability of the circuits to be zero set. The manual gives nice instructions for these tests.

The mechanical zero set of the meter before power up was spot on perfect and that huge meter is a delight to read! Even after a 5 minute warm up, with the wonky valve, none of the functions could be zeroed, but the meter did respond in each instance in the right way. Even the weak batteries in the Resistance Mode gave the correct response, stopping about 20 points off reaching full scale.

On powering off, the meter needle dove below zero on the scale and then quickly came back up to zero as the capacitors in the circuits bled out. So overall, in spite of no probes and leads yet, I am quite pleased with where this part of the project is headed.

The other interesting thing was finding a shipping label on the box from the Railway Express Agency dated August, 1948. This shipping company was a giant in its day; think modern day FEDEX. Worth looking up its history for a good read and discovering where todays American Express credit card company got its start, along with several other companies.



David

[David Dunlop]

Another stinky hot day today so I got all the errands/chores done early and retired to the basement to paint the two Spare Parts Cases. Both are now done save for any small touch ups after they have hard cured for a couple of weeks.

The green case, I will be adding to the 52-Set kit is the one in the foreground and the grey one is behind it.

The more I work with this Flat Olive Green colour that Canadian Marconi used on the 52-Set, the more it fascinates me. Note how, strictly on the way available light strikes the paint, the rear case looks olive green but the front one looks more like No. 2 Brown and out in the daylight this colour almost self-camouflages.

Once the hard cure is reached, I will be adding the stencil IDs to both cases.



David

[David Dunlop]

Oops!

I got a little ahead of myself in the last Post. That was actually just the first coat of Flat Olive Green paint. I got the second coat applied this evening and am still on target for the hard cure to be reached in 12 more days.


David

[David Dunlop]

Halfway through the hard cure time for the two cases now so I was able to get them right side up on the desk once again to finish the remaining week of curing.

There are a few small paint runs on one of the lips of one case that will need to be gently sanded down and possibly retouched once the paint is fully hardened but other than that, I will be able to get the Oil Board Stencil for the markings test fitted for the application of the original factory markings.


David