CALL BOOK 1920 - 1930 - Highfields Amateur Radio Club

About The Author
The Leicestershire Repeater Group launched a new repeater for the six-meter band.
This is GB3UM (Uncle Mike) which has been built and
dedicated specifically to the memory of ‘Jack Hum G5UM’
who’s story follows:
Jack Hum, the father of amateur radio in Leicestershire,
died at his home on January 11th, 1995. He was
84 years old and his passing will he mourned by the
whole of the Amateur Radio movement.
Just the mention of the call sign G5UM or the name ‘Uncle Mike’
immediately brings the name of Jack Hum into the conversation.
He was recognised as a man full of drive and energy who
pioneered and popularised the VHF and UHF Bands in United
Kingdom, everybody
seemed to know Jack
wherever you went.
Note no "G" prefix. You needed a special dispensation from those on high if you proposed
to work stations outside of these islands, and that didn't come until later where 5UM was
concerned. His earliest years were devoted to 160 metres simply because that was the easiest and
cheapest band on which to get started. Operation was mainly on c.w., because modulation
techniques of the day were rudimentary involving placing a carbon microphone in the earth lead,
and r.f. burns to the lips were not unknown.
The first introductions to "the very highs" came via the rushbox mode of self-excited
oscillator, again modulated by the carbon mike, and super-regenerative receiver. The bandwidth
of both devices was indeterminate and really didn't matter in those days of 56MC/s (before
Megahertz's came in). Ranges were short, performance minimal, but you made it yourself,
including the aerial and it was all great fun.
Then came the war and Jack served in the Royal Air Force on communications, rising in
rank to a Squadron Leader on Coastal Command duties.
After the great resumption of amateur radio in 1945, rigs had to be stable and crystal
controlled. The few dozen people you heard on the then 58 - 60 MHz bands could immediately
be identified by the crystal frequencies they used: you didn't need to wait for their callsigns.
"Uncle Mike" recalled that it was a great moment when he achieved his first ever QSO on
2m. The receiver was a TRF. The transmitter had just been completed and the output coil was
thrust into the tank inductor and held there while a CQ was pounded out. No wonder G5MA at
the other end reported QSB: it was Jack's hand shaking with excitement as he held the antenna
coil lethally against the tank coil.
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