Radio Direction Finding with the R1155 receiver
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- Опубликовано: 10 июн 2021
- This is a simple overview showing how to make the WW2 R1155 aircraft receiver work in Radio Direction Finding (RDF) mode. Whilst the R1155 is still a common enough device, very few exist today that still have working RDF circuitry and components installed.
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Thank you very much sir! Perfectly and concisely explained. I needed this information for a game called DCS as it was fitted in the Mosquito. However, my interest in electronics, particularly in how we solved these problems before the transistor and semiconductor age fascinates me and will bring me back for more.
Glad you found it useful. Interestingly enough, the manner in which the DF loop is repeatedly switched one way then back again by two valves and a transformer looks to me a bit like an early digital-style solution!
It's a beautiful thing. Ended up in here due to a video game called DCS, which is a flight simulator and now has the Mosquito Mark VI. In game the Mosie has this coupled with the T 1154 transmitter and now I know how to use them. Great video, and I liked what you did there, keeping this radio with the original function it had in WWII.
Me too
Thanks for the appreciative comments. Yes, these games do seem to become more and more detailed!
Same here. This a very helpful demonstration of the real thing. The R1155/1154 is simulated extremely well in DCS. You can interact with all of the controls. I've restored radios from this era and it feels very close to operating a real set, especially in VR. I've been obsessed with it!
Me too, too funny.
Thank you for that demonstration I have never seen that RDF system work before it’great
You're welcome :-) We always demonstrate this at events using a small hand-held transmitter, which shows how small a movement is needed to make the needles swing either way from 'straight ahead'.
That's interesting, thank you for the demonstration.
I always wanted one of these receivers and an AR88 but never got either. Always wanted a Wireless 19 Set too, which I did get a much modified one in 2017 and needed extensive work to improve it into a reasonable set.
G4GHB
You're welcome. Of course, the downside of buying one of these is the possibility of it being 'modified' by a previous owner. The one here had very little done to it, but still needed many months of work to replace all the miles of rubber covered wire that had perished!
@@lishaton My 19 Set had been modified already so I wasn't bothered modifying it further, B Set already gone so I put my my h/b inverter there, only 2 Watts QRP tx, xtal on tx. for stability using it's EF50, very deaf on rx- re-tune the i.f.t.'s,, extremely deaf in the c.w. position until I replaced the R's and C's in the audio filter, 2 coils O/C which I re-wound, some wrong wiring, BFO disconnected.
Much better now. 280 miles on 5.262 MHz c.w.. Pleased with that.
Excellent! :-)
Fascinating, thanks for all your hard work both in the restoration and filming.
73...
Many thanks for those kind words! :-)
I restored my R1155 with its DF section and made the loop antenna per specifications given in the AM handbook (that took some time..).
The dual needle meter (found in a surplus shop..even more rare) together with a long wire antenna gave a good account of itself showing a fairly accurate direction to the long wave commercial transmitter some 50 miles away.
Some years ago a senior friend who piloted Lancs on 460 Sqn RAAF (RAF Binbrook, Lincs) told me he never bothered much with the DF on home bound trips as the accuracy was not that good.
It's fun to demonstrate, though.
Since then I found another DF meter which is part of an AM test set to maintain the R1155 setup. Its only difference is a white background and a numbered amplitude scale up the vertical null line.
The deH Mosquitos were equipped with the R1155, too.
Cheers.
Thanks for the feedback Alexander. Some interesting observations too. I'm surprised to hear that your friend didn't think much of the accuracy of the DF when used seriously, else why was a 'sensitivity' switch added o the R1155? According to the book this was to alleviate possible 'pilot fatigue' if the directions from the meter were followed closely. No, I didn't know the Mosquito used the R1155. Remember also that one of the sets variant was used in the RAF Air-Sea Rescue lauches.
Good DF meters are hard to find. One of mine recently had one of its internal resistsance coils go O/C on me!
@@lishaton Pleased to get your reply, TRR. Re the DF, I think inaccuracies were not the fault of the set but more the vagaries of wave propagation associated with long distance reception; refraction, reflection meant that exact straight line (transmitter to 'plane) reception did not always occur.
I've seen the Air-Sea plywood cabinet with the 1155/1154 sets at Duxford.
Sadly, the three Lanc pilots I knew are no longer extant. Soon all will be gone.
Blowing a coil in the meter does not sound good!
I use my set sparingly remembering that valve filament life is reduced by frequent on/off cycles.
(Sorry for the delay, too, I'm 8.5 hours ahead of GMT. A mild spring morning here :-)
Very interesting. We have a few of these sets at the Lincolnshire Aviation Heritage Centre, where I work as a volunteer. And I'm in the process of trying to get some of them working. The latest one has been modified (very badly) to work off mains, my apprentice and I are in trying to get it into a usable condition.
I hope you manage to make it work! What with all the mods. one has to locate and restore to original, plus all the rubber wire one has to replace, both you and your apprentice have a long and tedious job ahead of you I fear! At least there is plenty of information available in the Internet for you to check the circuit etc. plus the performance of these sets is good when everything is done. Watch out for the power supply though, as the valves bias supply makes it a little unusual. Good luck to you both!
I was there back in july, saw this radio inside the display cabinet, always wondered if would ever be operated again.. i own one now and intend to make it operable
I have just purchased an R1155 an the T1154, they are both un-modified and complete. I also have the Power units 35A and 33B. I am hoping to connect them up and be able to transmit.
Good luck with your endeavour. I think that this may take you some time if the sets are totally original and untouched as there could well be many pieces of rubber covered wire all in need of replacement! Let us know how it goes.
@@lishaton Thank you. I have inspected the wire and it looks in good condition, but I will find a good military replacement as I don't want it to catch fire. Lots of other items to test. Yes it is going to take a long time, but best to get it right. Ill keep in touch.
Very interesting!
Thank you! If you're curious to know more about the circuit for the R1155, at least there are many schematics to be found on the Internet, showing how the direction finding actually works right down to component level.
I would appreciated more info on the antenna system...
The R1155 has several options when it comes to the aerial systems that could be used. In the case of direction finding, it used the DF loop (as seen here which was rotatable) and a fixed rod - the chrome telescopic in this case. With the Avro Lancaster, the DF loop was positioned behind the astro dome at the very back of the cockpit. I hope this helps!
Show!!!
Thanks! :-)