‘Upon arrival, the first thing was a few days introduction to the equipment we were to operate.  It went under the codename ‘ABC’, which stood for ‘Airborne Cigar’.  I have no idea why they named it that.  It consisted of three enormous powerful transmitters covering the radio voice bands used by the Luftwaffe.

 

To help identify the place to jam there was a panoramic receiver covering the same bands.  The receiver scanned up and down the bands at high speed and the result of its travel was shown on a timebase calibrated across a cathode ray tube in front of the operator.  If there was any traffic on the band it showed as a ‘blip’ at the appropriate frequency along the line of light that was the timebase.  When a ‘blip’ appeared, one could immediately spot-tune the receiver to it and listen to the transmission.  If the language was German, then it only took a moment to swing the first of the transmitters to the same frequency, press a switch, and leave a powerful jamming warble there to prevent the underlying voice being heard.  The other two transmitters could then be brought in on other ‘blips’.  If 24 aircraft were flying, spread through the Bomber stream, then there were a potential 72 loud jamming transmissions blotting out the night fighters’ directions.

 

The Germans tried all manner of devices to overcome the jamming, including having their instructions sung by Wagnerian sopranos.  This was to fool our operators into thinking it was just a civilian channel and not worth jamming.  I think ABC probably did a useful job, but who can say what difference it made?’

 

 

 

 

 

This article is from the Spring 2008 issue of Confound and Destroy