Information on Crystal units and -sockets

 

 

On this pages I show some information, gathered on crystal units and sockets, things I noticed and picked up.

It is a guessing matter. But as the Paraset was made in England, they will have used British xtal units at first.
The British used 3,2 mm (= 1/8") pins. As they did on tubes and many connectors.

 

But later in the war they must have started, using USA xtals with 4 mm pins.
USA dominated xtal manufacturing and USA had a monopoly on almost all the supplies in xtal rock, dug up in south America (Brazil I think it was).
It was far easier for the British to change the sockets than the Americans have to produce to sizes in pins.
Funny thing is: it happened: there were USA-made xtals with 1/8" pins.

 

Some photos can be enlarged.

 

Two British looking xtals. The left one marked "Signal Corps". Both have 1/8" pins.
   
Same units, top view.
   
Very popular round model. Like the one Bliley made.
   
with the 1/8" pins.
   
Here is an FT171-alike xtal housing that uses 4 mm pins. These fit in the sockets I call "Socket B". They also fit in the brown Phenolic xtal sockets, marked "Amphenol 33-3".
   
A mix of 4 mm and 3,2 mm (1/8") pins and sockets.
   
The wooden box Paraset had the 4 mm sockets.
   
These look similar to the Amphenol sockets. But they are made by McMurdo and fit for 1/8" pins. Compare them to the Amphenol socket, above. The 0,8 mm difference is hardly noticeable.
   
British xtal in a British xtal socket. Perfect fit.
   
These sockets, for 1/8" pins, were taken from an old rectifier circuit, using old tubes.
   
Finally, some other appearances of crystals.

Left: octal tube with xtal in it
Centre: a square xtal unit, made by Bliley USA but marked with broad arrow
Right: top and bottom: a Bliley xtal oven on octal socket. On top the heater element, bottom the xtal, kept on 70 degrees.