19-Set Crystal Calibrator

[sapper740]

I'm not sure when they were dropped but one of my crystal calibrators arrived in it's original, sealed box and has a RCEME inspection tag dated Nov, 18, 1959 from "202 BASE" RCEME Workshop. It was obviously never used after that date.

CHIMO!

Derek H.

[Dean (Ajax)]

I know some Cadet corps were still using them in the mid 70s.

Dean

[David Dunlop]

Anyone ever noticed these things are not waterproof by the wildest stretch of the imagination?

I have mine mounted horizontally on top of the Power Supply of my 19-Set Mk III. It in turn is mounted on a Carriers No. 23 'Breadboard'. The problem with this configuration, is the presence of the calibrator prevents the canvas cover from being securely fastened down to the carrier on the left side.

When I look at my Mk II 19-Set, mounted on a Carrier No. 21, with canvas cover, there is no way a calibrator can be mounted on that set and still have a functioning canvas cover.

A special canvas cover was developed for the Variometer. Does anyone know if a canvas cover, or storage case was ever produced for the crystal calibrator?

David

[Chris Suslowicz]

I think the calibrators were intended for use inside radio trucks, rather than anything where the set was exposed to the elements or liable to condensation dripping on it.

The British used a separate wavemeter (Class 'D' No.1) which was still not waterproof (initially, though there was a later version that was immersion proof when the lid/accessories container was clamped on). They were really only issued to control stations in higher formations during WW2 as far as I can make out: everyone else used the netting call from the control station who would pick a clear spot as close to the assigned frequency (on his dial) as possible.

Frequency inaccuracies were the main reason for post-WW2 sets being designed for crystal control, not to mention simple operation because the user might be getting shot at while trying to contact the net.

Chris. (G8KGS)

[David Dunlop]

Finally! One of these elusive little things has showed up on eBay from Utrecht, Netherlands under Item Number 173996967599. First one I have ever seen, considering every Calibrator Kit from Canadian Marconi was equipped with one.

On the very sad side, however, somebody during the life of this connector, deemed it necessary to hack the calibrator feed cable from it and cut off the brown resin ID ring. You can still see the ghost of where it was fitted to the cable.

Soooo sad!


David

[James D Teel II]

That’s terrible!

By the way, my crystal calibrator dog bone is a 12 pin.

[Chris Suslowicz]

Originally Posted by David Dunlop

Finally! One of these elusive little things has showed up on eBay from Utrecht, Netherlands under Item Number 173996967599. First one I have ever seen, considering every Calibrator Kit from Canadian Marconi was equipped with one.

On the very sad side, however, somebody during the life of this connector, deemed it necessary to hack the calibrator feed cable from it and cut off the brown resin ID rig. You can still see the ghost of where it was fitted to the cable.

Soooo sad!


David

My suspicion is that 333288844505 from the same seller may have been part of the calibrator at some point. (It's the right sort of cable with no outer jacket over the braid.)

The calibrator power leads were available in all three varieties: 6-6, 12-6 and 12-12, as were the control cables for the RF Amplifier No.2 (British WS19HP), but I don't think there was ever a power lead that supported both units.

Chris.

[David Dunlop]

Good eye, Chris.

I had seen that cable and it made no sense to me as is, but if you put the small steel tube, mounting clip and binding cord back on it behind the Pye Connector, there you have it...the output line from the chassis of the calibrator!

I suspect the small 3-pin Jones Plug fitting on the connector dog bone was needed for a project, which sealed its fate. Doubly sad, as I bought one a couple of years ago in case I needed it for my Remote Supply Power Cable for my 52-Set and it was a new manufacture item with ‘Made in Mexico’ on the label. But then why go to the trouble of removing the ID Ring from the dog bone? All it would have had on it was a small column of three ‘PL/C’ Numbers that give no real clue as to the purpose of the connector on their own.

Hopefully, now that we have seen the remains of this one, more of these useful calibrator pieces will start showing up in complete usable condition. There must be a number of Mk II 19-Set owners out there who would like to fit a calibrator to their set. I would bet some Mk II sets are already out there with the slow motion drive fitted to the frequency dial for calibrator purposes, but no proper dog bone anymore.

David