The Fprüf. b was a single-frequency signal generator that was used to calibrate the local oscillator of the 10W.S.a,b,c/ 20W.S.b,c,d transmitters & Ukw.E.b1,c1,d1 receivers; 25 - 48 MHz, Quarz 2.830 kHz. This signal generator employed a quarz 2.830 kHz.crystal to generate the necessary test frequency. The Fprüf. b was powered from the same source as the receiver and used a special power connector shown below. Different frequency quarz crystals could be used with this device.

The F prüf. b and the special power cable

 

 

Showing the ID plate and the power connector.

 

 

Headphone jack.

 

 

The interior. Notice the RV12P4000 tube, and the 35.625 MHz quarz crystal oscillator.

 

 

Closeup of the quarz crystal. oscillator.

 

 

The power coupling connector that fit between the EUa4 umformer and the Ukw.E.e. The third connector delivered power to the F prüf.b

 

 

Special connector for the F prüf. b

 

 

The two connectors next to each other for comparison.