[Peter G3YYN]

Many thanks to all who have replied. I clearly took a wrong turning in using the Oz Hemmant translation of "REL" to being "Radio Electronics Laboratories" rather than "Engineering" but have now been put right!.

My original source for the equipment type came from Pat Hawker's work simply as "a mixed bag of American (REL) 750W units and various British and Whaddon 100 -Watt and 30-Watt transmitters - of which only the REL units seemed to be equipped with fast -acting keying relays."
I'd also seen Geoffrey Pidgeon's work as well as the write up of his visit in the "Whaddon Quarterly", August 2016.

So the search now goes back to Radio Engineering Labs Inc of Long Island City, N.Y. with trade name: R.E.L, according to the Radiomuseum.org.

I'd be grateful if you'd cross post it to VMARS Roger. I have to say that I'd actually seen and passed over Armstrongs bunch at "that" REL some time back as being more domestic radio rather than high power tx people. Well maybe not as QRO as the stuff supplied by Press Association et al to the ACAN circuits.

The intriguing part for me is the reference to fast keying. This possibly suggests machine cw and paper reperforaters; and possibly leads to Creed machines later. Not something that naturally tallies with manual QRP cw circuits to France.

Peter