[ARC5] What did they talk to??

[AirRadio]

Hi, From experience of experimenting with these radios, On a Saturday morning AM net on 80m 19 sets will qso sensibly at around 50-70 miles, 62 set audiable not intelligable (carrier detactable)  at 50 miles using 1 watt and using the army issue amplifier to go with it( I believe is 15 watts but please correct me) 5-7 report over 50 miles. BC-375/BC-191 150 miles 5-7 report, ART-13 over 150 miles 5-9 report, TCS-12 over 120 miles 5-9, these were using a variety of antenna and trapped dipoles similar to WW2 style conditions, Portable results sitting on top of a hill in the New Forest, Southern England, were slightly better. On to the VHF sets, Well a different story indeed, SCR-522 mobile on flat ground 5 miles before no more signals, hilly ground lucky to get 3 miles. I do not have an aeroplane so no airborne results available, The base station transmitter BC-640 (50W)(companion to SCR-522) used on British bases during the later part of WW2, apart from the dreadful TVI we experienced ( tests were done in off peak times and the set was loaded up with filters of every description) the best distance we got using the SCR-522 as receive and BC-640 tx was 17 miles over varied reasonably flat ground.  IMHO I would think that the VHF was impractical for long distance and was only used for interference free (The Germans could not jam the VHF frequencies easily or over great distance or listen to it) assembly and inter aircraft communication work, It is well known that during assembly (before a raid all the aircraft assembled at an assembly point away from the airfield) the HF (command set) communications could easily in certain conditions be heard by the enemy (They at some points were only 30 miles away in France) therefore alerting them to the imminent danger, the VHF had a great advantage in as much as it was very clear audio (less misinterpretations and less midair collisions) and not able to be heard by the enemy. The VHF was not to my knowledge ever used to communicate back to base, only short morse messages on HF were used and as in the case of the 'Dambusters' raid was used to signal the success of the raid by a short coded message. There were not many HF sets capable of reaching into Germany during WW2 the only ones I know of are the BC-610 and 53set amongst others There is an RAF HF transmitter and the number escapes me for the moment is it AT4331? According to wireless operators reports of the time very little speech traffic was ever sent by liaison sets only CW. At 25000 feet I would think 60W or so will easily get back to the UK about 500 miles as the crow flies. I dont know whether anyone has details of solar acitvity during the war years or if there was evidence of high sporadic E?, I think this would have a reasonable bearing on the ability of certain communications....interesting... I hope this is of interest and will generate more of this interesting discussion, maybe others have tried similar things to me. 73 Max M1FDZ