No 11 Predictor - UK Vintage Radio Repair and Restoration Discussion Forum

Sean Williams · 13th Mar 2006, 5:57 pm

Well, it is a computer of sorts....

I just wondered if anyone knew if this was the correct predictor unit used with AA3 Mk7 gun laying RADAR?

Of course if anyone here has documentation for the unit then the Duxford Radio Society would be quite happy to recieve it - we are currently trying to assemble a complete system for display - we have the RADAR, and we also know where to find a No. 11 Predictor......

Cheers
Sean

peter_scott · 20th Mar 2006, 2:21 pm

Hi Sean,

I asked a friend who was involved with radar development and here is his reply. Hope you get something from it:

Peter.

Peter

I cant really help much I’m afraid, my information sources are a little limited on early UK radar and as a nation we have not done much to preserve hardware or data.

I do have a book which is supposed to be the bible on UK radar development “Watching the Skies”, unfortunately it’s a big thick official (HMSO) publication so inevitably its profoundly limited and erroneous in many respects. Could be worse, it might have been an NMS publication (how Logie Baird won the war / designed Concorde etc). Anyway, this book fails to mention an AA3 Mk7.

Digging through www.radarpages.co.uk/ I found this brief description :

http://www.radarpages.co.uk/download/radar_g97.doc

"AA No 3 Mk7
Fire Control with Auto Follow, 3GHz, Made by BTH, then Marconi. Improved version of AA No 3 Mk4. Used for SAGW trials 1945 in 1945, trials abandoned 1946. Trials called Brakemine."

No reference to the predictor to go with this, there was a lot of rapid (excessive?) development in the UK at this time. The UK was also being supplied by this time with the excellent US SCR584 which was relabelled AA No 3 Mk5, this included a built in predictor for associated guns and was used extensively and effectively in the huge anti V1 defences.

I’ve also looked through he IEE book “Radar Development to 1945” and although it mentions the AA No 3 Mk7 as the end of a development chain it makes no reference to predictors. Note that the references to “auto follow” are for automatic target tracking rather than having a man in the loop adjusting aerial directions etc. The IEE book does mention the SCR584 with its built in predictor as being used extensively. Curiously the APSS has just received a pair of handbooks for the SCR584.

So, I cannot dig up anything locally on the AA No 3 Mk7 and its predictor, I do wonder how many were made since we definitely were using many SCR584 relabelled as AA No 3 Mk5, there were a lot sitting around in storage yards in the late 1950’s.

Regards
David

13th Mar 2006, 5:57 pm	#1
Sean Williams Dekatron Join Date: Feb 2005 Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW Posts: 3,517	No 11 Predictor Well, it is a computer of sorts.... I just wondered if anyone knew if this was the correct predictor unit used with AA3 Mk7 gun laying RADAR? Of course if anyone here has documentation for the unit then the Duxford Radio Society would be quite happy to recieve it - we are currently trying to assemble a complete system for display - we have the RADAR, and we also know where to find a No. 11 Predictor...... Cheers Sean __________________ Engineers make things work and have spare bits when finished

20th Mar 2006, 2:21 pm	#2
peter_scott Dekatron Join Date: May 2003 Location: Edinburgh, UK. Posts: 3,274	Re: No 11 Predictor Hi Sean, I asked a friend who was involved with radar development and here is his reply. Hope you get something from it: Peter. Peter I cant really help much I’m afraid, my information sources are a little limited on early UK radar and as a nation we have not done much to preserve hardware or data. I do have a book which is supposed to be the bible on UK radar development “Watching the Skies”, unfortunately it’s a big thick official (HMSO) publication so inevitably its profoundly limited and erroneous in many respects. Could be worse, it might have been an NMS publication (how Logie Baird won the war / designed Concorde etc). Anyway, this book fails to mention an AA3 Mk7. Digging through www.radarpages.co.uk/ I found this brief description : http://www.radarpages.co.uk/download/radar_g97.doc "AA No 3 Mk7 Fire Control with Auto Follow, 3GHz, Made by BTH, then Marconi. Improved version of AA No 3 Mk4. Used for SAGW trials 1945 in 1945, trials abandoned 1946. Trials called Brakemine." No reference to the predictor to go with this, there was a lot of rapid (excessive?) development in the UK at this time. The UK was also being supplied by this time with the excellent US SCR584 which was relabelled AA No 3 Mk5, this included a built in predictor for associated guns and was used extensively and effectively in the huge anti V1 defences. I’ve also looked through he IEE book “Radar Development to 1945” and although it mentions the AA No 3 Mk7 as the end of a development chain it makes no reference to predictors. Note that the references to “auto follow” are for automatic target tracking rather than having a man in the loop adjusting aerial directions etc. The IEE book does mention the SCR584 with its built in predictor as being used extensively. Curiously the APSS has just received a pair of handbooks for the SCR584. So, I cannot dig up anything locally on the AA No 3 Mk7 and its predictor, I do wonder how many were made since we definitely were using many SCR584 relabelled as AA No 3 Mk5, there were a lot sitting around in storage yards in the late 1950’s. Regards David