Help please Mk 11 aircraft Friend or foe transponder

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9 years 6 months

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Hi
Would anyone have any images of a R.3002 12 volt IFF (friend or foe) transponder unit.
along with any other information on this crucial part would also be very much appreciated.
Thank you in advance

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Profile picture for user Beermat

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10 years 7 months

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Images of a plain vanilla MkII seem impossible to find - I have tried before. You can get the dimensions from factory GA's of aircraft that carried them, but that's about it. Later versions are easier to find - the first below is a MkII, but not a 3002 it's a 3019 - a MkIIN.. The second one is a MkIII, while the third is a US copy of the MkIII, used as much by the USAAF as the RAF- this was the SCR 595. The designations are complex - though they all looked pretty similar.This site - https://www.qsl.net/pe1ngz/airforce/...af-iff.html#II - really helped me understand about IFF - essentially the differences between early IFF were all about what radars they responded to. The 3002 MkII responded to Chain Home, Mk IIN responded to Chain Home Low
..

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9 years 6 months

Posts: 753

Hi Beermat
Thank you for your reply, so would you know when the R.3002 would of come into service?also the photo on the link IFFN is identical to my control unit (sorry cant seem post an image) but if you go onto the Facebook page "factory stamps" around 6 or 7 posts back you can see some photos of my relic control unit, that also shows the Air ministry plate AM 10LB/3 serial no 2652, sorry for my ignorance but where would he transponder and control unit be situated? as im afraid this is not my speciality.
Also attached to my control unit is another Air Ministry plate R.3002 ref no 10DB/1 serial number 2647 this i take it would be with the transponder unit, looking on the list on the link it is showing R.3002 as a Mk11 can you please confirm this.

Any help on this would be very much appreciated.

Profile picture for user Beermat

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10 years 7 months

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Yes, the R.3002 would have been in use from late Sept or October 1940 - up until then IFF would would have been via the ''pip squeak' channel on VHF. (The MkI was something different from Pip Squeak and just a trial prototype). Yes, the R.3002 is a Mk II - that's II, Roman numerals, ie 2, not '11'

So the control unit sits in the cockpit, usually somewhere fairly out-of-the way on the side. On a fighter it would be somewhere behind the pilot normally, on a bomber it would be in with the radio equipment. here's the way it all went together - unfortunately the site's in Italian - http://www.carlobramantiradio.it/iff.htm

You are not alone in not knowing specifically where the IFF unit would be in any specific aeroplane. They were so super-secret they were left out of all drawings, photos, APs and descriptions published during the war, and very many 'experts' now couldn't point to where the actual transponder, quite a large unit, sat in a Spitfire, the most drawn, described and deconstructed fighter in the world, despite knowing pretty much where every rivet should be. Modern cutaways leave them out, and you won't find it via Google, I'm sure you tried, and I just did as well!

The exact positioning of the R.3002 transponder box in the Spitfire is one of the best-kept 'secrets' in Historic aviation, although really it's just a hole in knowledge caused by wartime secrecy - I am sure someone will be along with the appropriate Supermarine drawing showing the mounts (it exists as I've seen it).. In the meantime you can get an idea where it was from where the two diagonal IFF aerials enter the fuselage:

[ATTACH=JSON]{"data-align":"none","data-size":"medium","data-attachmentid":3870026}[/ATTACH]

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Profile picture for user QldSpitty

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14 years 1 month

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Below the radio rack on the Spit off memory Stbd side?The pipsqueek box was a waterproof sealed clockwork unit that lasted for 24hrs off memory.

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9 years 6 months

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Thanks again Beermat for your detailed reply that goes along way in explaining the IFF usage and description along with an image of what mine use to look like, I’ve added a link below showing my relic control box as this is the only one I have ever come across.

Thank you also OldSpitty for adding its location within the Spitfire I’ve searched the net and as yet I haven’t seen one in situ.

https://www.facebook.com/groups/941506995941029/permalink/2390810714343976/

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I have an example of an R3003, the 24v version of the R3002, but it's currently in pieces for repair and not very photogenic!

Andy

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Beermat, where is that photo from? Apart from obviously being Gib, the personnel look American (in fact, is that one or another movie star on the wing?).

Adrian

Profile picture for user Beermat

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10 years 7 months

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It's here - http://spitfiresite.com/2010/04/uncl...spitfires.html - credited to 'American Memory', whatever that is. It looks to me like a posed shot for Time, or Life or similar. The caption reads "Americans in Gibraltar. US pilots pose in a Spitfire Mk. VB for the benefit of the press prior to the Operation Torch (sic). Left to right, they are Colonel Harold B. Willis, Major Marvin L. McNickle and Captain Arnold Vinson."

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9 years 6 months

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Hi AndyY
Sounds interesting would be great to see when it is restored, would anyone else have or come across a R.3002?

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8 years

Posts: 421

It's a slow job, more a 'background task'. When I got it it had been stored in damp conditions, so lots of rust on internal steel parts, and must have been sat on by an elephant. I removed the battered parts of the case and successfully straightened them a few years ago, and started looking for missing or broken parts, for example one of the variable capacitors driven by the external crank was smashed. I now have the correct replacement part, also one of the bakelite parts of the crank mechanism which was broken.

Andy

Profile picture for user NewQldSpitty

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2 months 1 week

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Any updates on some photos?Im starting to put a radio set into a bay at the moment.Tr1143,Tr5043  or SCR-522..