German Radios and Quartz Crystals

[cris2006]

Hi All,

We all hear about how Germans managed to produce their radios without depending on quartz crystal oscillators to stabilize frequencies. But how did the Germans actually achieve that? Were WWII German radio sets really never made with crystals inside their mechanism? How did they overcome this problem of lack of crystals? How did this impact on performance and quality of their radio sets?
I appreciate your comments.
Thank you.

Best Regards,

Cristiano

[Val]

There are several articles written about that theme, by Arthur O. Bauer PA0AOB and Dick Rollema, PA0SE

Those came first in mind.

http://www.nonstopsystems.com/radio/...le-hell-24.pdf
http://www.nonstopsystems.com/radio/...arthur-trx.pdf

[Val]

Also read this.

www.cdvandt.org/DEHS2008-def.pdf

[la5he@yahoo.no]

Christiano. I have only seen German sets used by the intelligence services with crystals ( Spying/counterespionage). Aufklaerung-Abwehr.
The biggest transmitter I know is my own RS20M.

rgds Ragnar

[Val]

TFuG.k, for example, used leuchtquarz for frequency calibration.
Which german sets beside that used leuchtquarz - electroluminescent crystal?

[Funksammler]

The 1933 Torn.Fu.a used crystals to stabilise the transmitter but after that all military sets all used stable variable frequency oscillators. Arthur's article describes very well how this was achieved: The use of injection molded alloys to create very stable chassis, the use of ceramic technology to make stable capacitors, the use of iron dust core technology to make stable self inductions and the development of small rugged radio tubes. Add to this the clever designs combining Positive and Negative temperature coefficient components and you get very stable equipment without frequency drift.

A nice example of this is the Torn.Fu.d2, the tuning capacitor and coil are mounted to the the same ceramic shaft. As the temperature changes, the assembly will expand and contract by a very small amount, changing both the capacitance and inductance in the oscillator circuit. The design is however perfectly balanced to that the LC constant remains the same.

The germans did make widespread use of crystal calibrators. Because of small variations of internal capacitances of the radio valves, the radio's did require a tune-up after a valve change, this could quickly be achieved by using the appropriate calibration set.

The Radione RS20 is one of the few exceptions, but this was a commercial set adopted by the military due to a shortage of short wave equipment (the long distances in the African and Russian campaign exceeded the range of the "groundwave" equipment used by the army, so a quick solution had to be found; commercial shortwave sets like the RS20 and LO70K39 were pulled into service....)

regards,

Funksammler

[cris2006]

Many thanks Val, Ragnar and Funksammler for the comments and indication of articles - it is all very clear now!

Best Regards,

Cristiano

[Val]

About that leuchtquarz:

http://www.radiomuseum.org/forum/leuchtquarz.html

Also LA6NCA has nice page of the TFuG.k.

Pay attention to the "Kontroll quarz" hole.

http://fykse.dnsalias.com/radio/tfugk/

[Tornfuté]

Hello about Quartz
All up to date sets have quartz like e52 e53
Main wupper , also fu h e a,b,c,d,e,f,u ,v
Ez6 ebl 2 generator has an illuminating quartz
My goliath tx , has 3 quartz
30 wsa or 80 ws
Kwea or Lwea
It ´s just a small list
And as written by others a lot of other calibrators ....
Pierre

[Funksammler]

All these crystals are used for calibration only, which is different from the specific sets mentioned that used crystals to stabilise the transmitter's frequency oscillator. With these latter sets you have the change the crystal if you change the channel (as is the case with much of the US equipment of the time).

Don't know about the Goliath transmitter, what are the crystals used for in that set?

regards,

Funksammler

[Tornfuté]

hello in Goliath , it's 3 round quartz made by Dr steeger working
i believe in the 40 Mhz , it's used i think for stabilizing oscilator frequency , they are 3 channels
pierre

[cris2006]

Hi All,
Many thanks for all the comments.
About the crystal calibrators, any idea how long the crystals would last in these devices before they were replaced?
Were these calibrators kept in maintenance workshops in the rear or elsewhere?
I wish you all a nice weekend!
Thank you.
Best Regards,
Cristiano

[Funksammler]

The crystals are pretty robust, most are still in perfect working order after 70 years so I do not think replacement was a big issue.

Sometimes the crystal calibrator was contained within the set, for example with the Torn.Fu.d2. The radio crew itself would be responsible for calibrating the set after a valve change.

The calibrators would probably be carried by the staff unit of the signals battalion, typically operated by the "Funkwarte" in the unit.

regards,

Funksammler