IFF

[Sussexhurricane]

Hello,
I have got a couple of WW2 IFF boxes with a wind-up system.Saw one in a Museum said to be out of Spitfires,Hurricanes etc.Does anyone have any information about these things.

[Airframes]

Sounds like the Remote Contactor Unit, normally fitted on the starboard cockpit wall of Spitfires etc. This set the delay between transmission times of the outgoing 'blip' signal, normally around every 12 to 14 seconds, which identified the aircraft as friendly on our radar screens. Basically, the forerunner of today's transponder, used to identify individual aircraft to ATC radar operators.

[Sussexhurricane]

Looking through some old pictures when I found some.Was going to put them on ebay a few years back.Would it be worth it?

[Airframes]

Ah, it's not the remote unit I described. If it's part of an IFF set, then it's a later style, very possibly from a multi-engine aircraft.
It looks like the 'counter' at the bottom right hand corner may even be the frequency indicator, very like modern-day transponders. Could possibly be post war.

[Edgar Brooks]

It's possible that it's the I.F.F. Mk.I, used right at the beginning of the war. I was told that Peter Vacher, while he was having Hurricane R4118 rebuilt, moved heaven and earth to get hold of an original (clockwork-driven) set. If you can contact him, and send your photos, he might be able to cofirm that it's the same item.
Edgar

[ramc181]

That appears to be a Master Contactor, which the Remote Contactor was connected to.
The counter is possibly a later addition, and may be completely unrelated to its original purpose.

When these items became available on the surplus market they were adapted for all sorts of uses.
I was reading a 1960s DIY article yesterday on how to install automatically opening and closing curtains in the home using one as the timer mechanism.

All the best,
PB

[Observer1940]

I don't know what you have. But on a WW 2 aircraft IFF set, MAKE SURE the detonater has been expertly removed and the unit is safe.

DON'T connect it to a power supply and GET PROPER ADVICE.

I have just been reading a book by a WW 2 Wireless Op and if a WW 2 RAF bomber aircraft had to force land in occupied territory, the IFF box was switched to detonate on landing, to destroy the IFF Unit.

I know nothing else about the IFF guts / wiring of the unit itself, I don't know what the IFF detonater looks like and have no technical literature.

Mark

[Matt308]

Wise words of warning. I know the later war US IFF had destruction devices that were as a minimum manually initiated. That is the extent of my knowledge. If you have no means of determing if the IFF has been demilled, treat it with caution.