Wireless Set No. 52 Canadian - Project

[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

[David Dunlop]

So far this week, all I have been doing on the Main Set Receiver each evening has been to turn it on and let it warm up for 10 to 15 minutes. Then I turn on the Crystal Calibrator, let it warm up an equivalent amount of time and then randomly tune to several frequencies on all three Bands of the receiver.

Interestingly, at the start of this process, I had difficulty finding the calibrator signals on Band 3 (7.5 to 16 MC). Now, for some reason, I can track the calibrator all the way through Band 3. Granted, both RF and AF GAIN Controls are maxed out and you really have to pay attention, but they are there now. I cannot help but wonder is after so many years of inactivity, and misalignment, sufficient electrons are now flowing through some of the components once again, they can actually start doing what they were intended to do.

I have also cleaned the 9 Trimmer Capacitors in the RF Coil Assembly and have been dabbing their central tuning cores with alcohol each night in an effort to break up any dirt that might prevent them from turning. The plan for the coming weekend is to realign all the 8 Trimmer Capacitors in the IF Coil Assemblies and then do an alignment of the RF Coil Assembly and see how that affects the performance of the receiver.


David

[David Dunlop]

I had the Main Set Receiver over at a friends place this morning to have him mentor me through the alignment process for the RF Coils Assembly. I worked through the process twice and at the end of it the receiver now has signals booming in across all three bands. His part of town seems to have a lot less radio interference than mine does.

With the Main Set Receiver now back in the Carriers No. 4 and no longer deaf, I made an interesting discovery There is an open circuit somewhere in the Sender where the Aerial Feed passes though to the Receiver. When I bypassed the suspected problem area with a jumper cable, the receiver sprang to life with contact to my dipole aerial out back and WWV came booming in loud and clear on Band 3 at 10.0 MC on the dial. All sorts of other signals were to be found as well. Interesting that with the receiver completely deaf before the alignment work was done, I was completely oblivious to this problem.

The plan now is to bring the Remote Receiver up to this level of performance and then go back to the Sender. I have to complete the cleaning of oily soot from the lower chassis surrounding the 813 Valve Socket anyway and can take a closer look at the aerial circuit as well. I suspect it might be a problem in the Band Selector Switch but could also be the relay in there that disconnects the receiver from the aerial circuits when the set goes into transmit mode may be stuck open for some reason. Over all though, it was a great day!

David

[Chris Suslowicz]

Originally Posted by David Dunlop

With the Main Set Receiver now back in the Carriers No. 4 and no longer deaf, I made an interesting discovery There is an open circuit somewhere in the Sender where the Aerial Feed passes though to the Receiver. When I bypassed the suspected problem area with a jumper cable, the receiver sprang to life with contact to my dipole aerial out back and WWV came booming in loud and clear on Band 3 at 10.0 MC on the dial.
...
The plan now is to bring the Remote Receiver up to this level of performance and then go back to the Sender. I have to complete the cleaning of oily soot from the lower chassis surrounding the 813 Valve Socket anyway and can take a closer look at the aerial circuit as well. I suspect it might be a problem in the Band Selector Switch but could also be the relay in there that disconnects the receiver from the aerial circuits when the set goes into transmit mode may be stuck open for some reason.
David

The most likely culprit is the transmit/receive relay - either stuck in the transmit position or not making contact (dirty contacts) in receive. Another possibility is a short circuit somewhere in the aerial wiring or the gas protection tube is faulty.

But a great day nevertheless.

Chris.

[David Dunlop]

So this weekend is the time for me to align and calibrate the Remote Receiver for my 52-Set. First step will be doing the two IF Coil Assemblies and see where that leads things.

The RF Input Signal I will be using this time will come from my early 1950’s Stark Signal Generator. I tested it out a few days ago and found it is very well calibrated, compared to my Canadian Model SG-1 Signal Generator. I need an output signal of 420 Cycles with a 400-cycle modulation. 420 Cycles is well below the frequency range of the receivers I have on had, but I realized I should be able to tune in the 5th Harmonic of that signal at 2100 KC on the Remote Receiver. I was indeed able to find it and it was exactly at 2.10 MC on the Receiver Dial, which told me the 420 Cycle setting on the Signal Generator, was spot on.

Getting a test signal into the receiver is the start, but you need a good reference output to adjust to. The recommendation is to bypass the speaker entirely and use one of the Phone Sockets to put a meter across and tune t the optimum deflection on the meter.

As it turned out, one of the other vintage bits of test gear I have had sitting quietly on a shelf over the years is a 1945/46 SOLAR Model CF Exam-eter. Its primary claim to fame all those years ago was it was one of the first pieces of test gear that could accurately test capacitors while they were still fully connected to their circuits. Typically, without such a piece of test gear, one has to remove one end of the capacitor at the very least, or completely remove it to get an accurate reading. As well as testing capacitors, this Meter does all the other things a VTVM can do and more. What caught my eye when reading the manual last week was that this meter can be used for Alignment Work.

Since I am going to have to go though the alignment process with this receiver 2 to 3 times to really fine-tune it (and go back one more time to redo the Main Set Receiver). I thought a more permanent Test Lead would be in order, rather than jury-rigging something temporary.

What I came up with is built around what the Eagle Eye Wireless Owners out there will recognize and the cord from a Morse Key No. 9 that I had parted out some years back and if I ever need it for its original purpose again, it is very easily restored back to original condition.


David

[David Dunlop]

It is getting a little crowded on the work desk now.

From left to right in the attached photo are the Remote Supply, the Stark Signal Generator, the Remote Receiver and the Solar Exam-eter.

It will be interesting to see just how much this receiver has been played with in its past Life.

Although it can tune in stations across all three Bands, it is not as crisp as the Main Set Receiver now is, which is interesting because up until now, this Remote Receiver had been my performance bench mark.

What I have found interesting so far is if you try and tune any signal in to a ‘Zero Beat’ point, the top half of the Zero Beat cycle is chopped off and the bottom half seems much more extended than it should be. I am now somewhat curious if a prior owner was trying to retune this receiver to pick up lower sideband signals, but still have not wrapped my head completely around what is going on.


David

[David Dunlop]

A rather eclectic weekend of 52-Set work has just passed.

First and foremost, with the help of a lot of colourful muttering to myself, I was able to tune all the Trimmer Capacitors in the IF Coil and RF Coil Assemblies of the Remote Receiver. It helped a little bit, but not enough to get rid of the chopped Zero Beat Tuning phenomenon. I am going to have to bite the bullet and retune all the related coils. That will be a real challenge as two of them carry a HUGE amount of electrical potential and a proper insulated adjustment screwdriver is essential for that work. So I will have to schedule humping the Remote Receiver to my friend’s place down the road to finalize the adjustments this receiver needs.

With that out of the way, I decided to revisit the Sender to see why the aerial feed between it and the Receiver lacked continuity, so out that brute came from the Carriers No. 4 for a closer look.

A close inspection of the suspect Relay Switch proved it was in perfect working order and so was the Band Switch. That brought me back to the Aerial Output Socket on the Sender. I discovered two things there. First, the screw holding the Plug on the end of the Aerial Feed Cable was loose. Turned out an internal toothed lock washer was missing and the Plug was loose enough on the terminal fitting of the cable to produce intermittent isolation. Second, the Plug itself was a very loose fit in the Aerial Socket. Every other similar socket on hand produced a very snug fit for the Plug. By gently sliding a small slotted screwdriver between the four Socket Tabs and the Sockets large Bakelite housing, I was able to close up the gap for a much better Plug fit.

When getting ready to put the Sender back into the Carriers No. 4, I found the lower Shakeproof Cowl Pin on the Blower Door would not unlock. I have found it very helpful to have this door open when reinstalling the Sender in the Carriers No. 4. It provides easy access to the Sender chassis to nudge the Sender fully home. The two Knobs on the lower part of the Sender do not provide enough leverage to move the mass of the Sender in its upper portion where the two 8-Pin Connector Plugs need to link up. A careful look behind the Sender Panel revealed the Locking Pin in the Shaft of the Lower Shakeproof Fastener was falling out. I then remembered it was a much looser fit when installing it than the upper one. I was able to get it out and replace it, but this time let a little clear nail polish wick into the pin hole to hold it in place. Those two Shakeproof Cowl Fasteners on the Sender Blower Door still are a mystery. The upper one I have is shorter than the lower one and does not engage the Receptacle on the Sender Chassis at all. The lower one works just fine. Two more exist on the Receiver Section of the Supply Unit. The Parts List gives three Shakeproof Cowl Fasteners in use on the 52-Set but no reference at all to which ones go where. I am going to have to resort to a survey of all owners of surviving 52-Sets to determine what they have in their sets and see if some consistency turns up for working fasteners in both locations.

Once the Sender was back in the Carriers No. 4, I reconnected everything and fired it up once more. Happy Dance! I had full continuity from the Receiver all the way through to the dipole aerial outside. Even nicer to hear for the first time, were the changes in audio output in the Receiver when the Sender Band Switch was changed to and from the same Band at the Receiver was set to, and the three Tank Coils used in the Sender to tune it and the Receiver to the aerial in use, were finally working. Now I just have to get the Coils, Aerial Tuning No. 2A linked into the system.


David