I expect it really isn't too different than today. Firstly you use a certain frequency, with there being as many as 10,000 possibilities, and then you keep radio transmissions short (say below 20 seconds). There are different ways of speaking on a radio, plain English, discreat, and code. Most often I assume a forward observer would speak in discreat language, with anything important being coded. Then of course there is output power, a user of a HF set will not use enough power to transmit 100 miles away if his guns are only 5 miles behind him.

Yimmy, Thanks for the info. So I take it the artillery unit and its FO would coordinate at the start of operations the code and frequency, and then follow it from there? Now, if a FO post is overrun, could the overrunning troops figure out the code and spoof the artillery unit or would the code not be written down? Thanks...

There's a page about Brit, etc, arty comms in WW2 on this site http://members.tripod.com/~nigelef/index.htm. IIRC it also has a page about 'fire discipline' and examples of fire orders. There's no need to 'code' fire orders unless the target is going to be engaged other than immediately, eg in a fire plan. Occasional spoofing attempts were made, as was jamming. However, if an operator was suspicious he challenged and sought authentication. The point to remember is that in a battery and even on a higher net, everyone recognised everyone else's voices, a new voice would get some discussion among a crew ('must be new bloke just arrived'), furthermore there was also the matter of 'call sign', if you suddenly hear an unknown voice on your net using your call sign then you're likely to say something! Even with morse experienced operators recognise each other's 'hand'. Last time I head of an attempted spoof in morse was 1966 in Borneo by the Indons against a Brit arty net, they tried to call a for fire, didn't work there either. Incidentally it was the same bty at much the same time (a few months) that unusual atmospheric conditions caused interference between their net (VHF this time) and a US net in SVN: US operator "get off this means, this is operational", Brit signaller Gnr Mc**** in broad Glaswegian without being prompted: "so's this and we're winning ours", which just demonstrates that the average Brit gunner is smarter than the average US General :-)

Neutralizer, Thanks for all that great info!

An interesting old topic. I suspect a lot of signal intel work related to this question was classified secret & the documentation either lost or never adaquately researched and published. A couple other items I suspect: The Germans and Soviets never had as much radio equipment as the US and Britian. Wire comm links were very common for both. Even with the US and Brits wire was prefered when there was time to lay it. When I retired in the late 1990s we were still laying wire routinely. Second I'd guess the intel people were more concerned with just listening in for stuff of longer term value.

UK did use tactical sigint, IIRC in the signals world they were called the 'Y service' (I think this tradition lives in with the EW troop in 3 Cdo Bde).

The Y service did the full range of tactical/operational sigint. Which included the artillery comm. But I dont know how active they were specificly with artillery comms.

Over on Consimworld I've been pitched a question about Brit artillery in operation GOODWWWOD, which is compltely beyond me. Do you have any knowledge of this? The question concerns a perception that the artillery was signiifcantly less effective in the latter stages of GOODWOOD.

Not particularly, however, it's possible that the full depth of the German position was beyond the range of 25-pr without redeploying.

That is Mr Hadelys question. He noted this is the offcial 21st AG explination. Crowded roads, packed bridgehead & all that. He was wondering if there was another explination.