[SMCARA] Special Event

[Clarke, Tom AIR4.0P NATOPS]

Worked an interesting station on 17m  RTTY.

 HF70OMG from Poland.  Marking the 70th anniversary of Polish participation in Operation Market Garden in Holland during WW2.  This was the allied operation to capture the bridges on the Rhine River at Nijmegen and Arnhem (among others) and was the subject of a book and movie named "A Bridge Too Far".

An interesting aspect of this operation was the total failure of radio communications during the battle.  Several  factors caused this failure:
1)  Choice of frequencies- 2 to 5 MHz
2)  Lack of crystal control to "net" the radios.  Operators were typically "grunts" and not comm types.  Easily bumped off frequency.
2)  Many radios were damaged or destroyed during the airborne invasion (paratroops and gliders)-not very sturdy.
3)  Low RF power output, 1-5 watts
4)  Lack of battery replacements or lack of charging facilities for storage battery radios.
5)  Poor Antennas.  Most were short rod types only good for a mile or so, ground wave.  Verts not as good for skywave prop.

Typical radios were Wireless Set #22 and Wireless Set  #68.  Some Wireless Set #19 radios were used in vehicles.  You can still find WS 19s at hamfests now and then. WS 19s had a VHF (around 200 MHz) side as well as HF.  This was a MOPA transmitter and a Super-regenerative receiver.  They were truly horrible with a very short range.  They were primarily for tank to tank comms up to a couple of hundred yards.  The US radios were not a lot better- SCR-300 and BC-611 Walkie Talkies, however they all used crystal control.  Early in the war we discovered that crystal control was essential and crystal manufacturers went full tilt to produce enough "rocks" for the military. You can still see boxes of FT-243 crystals at hamfests.  They must have made millions of them.

 Aircraft radios suffered the same shortcomings until crystal control came along.  A pilot could reach down and crank the "coffee grinder" tuning control and then wonder why he could not hear anyone! Aircraft that carried a radio operator usually had better comms.  The radio op could use the BC-221 or LM frequency meter and tune the radio smack on frequency, then let the pilot talk or he could send the message in CW. US tanks also used the WS19, but later in the war went to FM transceivers in the 30 MHz FM range (SCR-608).

Can you imagine the difference it would have made if a couple of hundred Boo Fungs or Woof Hongs were dropped in with the parachutists?

73 Tom/W4OKW