Aircraft control unit. - UK Vintage Radio Repair and Restoration Discussion Forum

HMV 1120 · 15th Jul 2008, 8:36 pm

I got this recently. It has the air ministry part number 10L/250 (Control Unit type 387) stamped on the casing. A quick search has revealed 10L to be a radio control unit prefix. A penciled number on the back turns out to be aircraft serial WG225 - Balliol T2 training aircraft. Bilt 1953, scrapped 1961. So far, so good. But I'd like some suggestions as to what it actually did.

'On' and 'Vol' are pretty clear to work out, but anty idea as to what 'SBA' is, or VHF SBA IC?

Whilst loooking in good order, the phantom fiddler has been here before. Both wires to the On/Off switch have been neatly pulled off and tucked away. Otherwise it is yet another paper weight. Unless I manage to find the rest of the aircraft...

Sean Williams · 15th Jul 2008, 8:39 pm

Rob, looks like an interface to the aircraft's VHF radio, or Intercom - would be sited so the crew members could control their comms equipment as needed

Sean

repairman 1234 · 16th Jul 2008, 8:01 pm

Hi,

Maybe worth a dig around on www.spitfirespares.com If your in luck this site may give an insight into its use and even value, i would agree with Sean though, it does look like the crew radio interface. Nice to have a slice of history, even if you do only end up using it as a paperweight!

all the best,

Chris.

GMB · 16th Jul 2008, 8:58 pm

The RAF Hendon archive will be able to tell you what it is.

rv2p800 · 18th Jul 2008, 10:22 pm

SBA can mean "Standard Beam Approach" witch was the German "Lorenz system" - a forerunner to the American ILS Instrument Landing System.
A transmitter operating at about 33MHz with a simple phased antenna-array at the end of the runway. When approaching the runway on its center-line the pilot would hear a single note in his headset. Deviating to one side, he would hear dots, to the other side dashes.

In addition there would be two marker-beacons before the runway, one some kilometer out, and one near the runway to indicate that the runway is stright ahead - you may land.

The Brits bought the Lorenz system before the war and used it. The 8'th Airforce did not have suitable receivers for their bombers so a series of AN/ARC-5 receivers where modified for that task. The Germans however, also used the system in reverse, with larger antenna-arrays and more power - for "Beaming" their bombers to England -.

More (and more accurate...) information may be found on the net ;-)

Regards Erik

HMV 1120 · 22nd Jul 2008, 8:31 pm

Sorry for the delay - been little busy ths end (have found a dino! Long story

)

Thankyou all who have replied. An intercom type arrangement would make sense - the aircraft was a two seater.

Would that sort of beam approach still be in use long after the war? and why would a switch differentiate between 'SBA' and VHF SBA?

More digging to do... Thanks for the ideas...

15th Jul 2008, 8:36 pm	#1
HMV 1120 Hexode Join Date: Jan 2007 Location: Weeting, Norfolk. Posts: 465	Aircraft control unit. I got this recently. It has the air ministry part number 10L/250 (Control Unit type 387) stamped on the casing. A quick search has revealed 10L to be a radio control unit prefix. A penciled number on the back turns out to be aircraft serial WG225 - Balliol T2 training aircraft. Bilt 1953, scrapped 1961. So far, so good. But I'd like some suggestions as to what it actually did. 'On' and 'Vol' are pretty clear to work out, but anty idea as to what 'SBA' is, or VHF SBA IC? Whilst loooking in good order, the phantom fiddler has been here before. Both wires to the On/Off switch have been neatly pulled off and tucked away. Otherwise it is yet another paper weight. Unless I manage to find the rest of the aircraft... Attached Thumbnails __________________ Real radios glow in the dark M6GLD Last edited by Darren-UK; 16th Jul 2008 at 1:53 am. Reason: Purge on enormous embedded images.

15th Jul 2008, 8:39 pm	#2
Sean Williams Dekatron Join Date: Feb 2005 Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW Posts: 3,517	Re: Aircraft control unit. Rob, looks like an interface to the aircraft's VHF radio, or Intercom - would be sited so the crew members could control their comms equipment as needed Sean __________________ Engineers make things work and have spare bits when finished

16th Jul 2008, 8:01 pm	#3
repairman 1234 Retired Dormant Member Join Date: Sep 2007 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 749	Re: Aircraft control unit. Hi, Maybe worth a dig around on www.spitfirespares.com If your in luck this site may give an insight into its use and even value, i would agree with Sean though, it does look like the crew radio interface. Nice to have a slice of history, even if you do only end up using it as a paperweight! all the best, Chris.

16th Jul 2008, 8:58 pm	#4
GMB Dekatron Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 3,095	Re: Aircraft control unit. The RAF Hendon archive will be able to tell you what it is.

18th Jul 2008, 10:22 pm	#5
rv2p800 Triode Join Date: Dec 2007 Location: Sola, Norway Posts: 24	Re: Aircraft control unit. SBA can mean "Standard Beam Approach" witch was the German "Lorenz system" - a forerunner to the American ILS Instrument Landing System. A transmitter operating at about 33MHz with a simple phased antenna-array at the end of the runway. When approaching the runway on its center-line the pilot would hear a single note in his headset. Deviating to one side, he would hear dots, to the other side dashes. In addition there would be two marker-beacons before the runway, one some kilometer out, and one near the runway to indicate that the runway is stright ahead - you may land. The Brits bought the Lorenz system before the war and used it. The 8'th Airforce did not have suitable receivers for their bombers so a series of AN/ARC-5 receivers where modified for that task. The Germans however, also used the system in reverse, with larger antenna-arrays and more power - for "Beaming" their bombers to England -. More (and more accurate...) information may be found on the net ;-) Regards Erik

22nd Jul 2008, 8:31 pm	#6
HMV 1120 Hexode Join Date: Jan 2007 Location: Weeting, Norfolk. Posts: 465	Re: Aircraft control unit. Sorry for the delay - been little busy ths end (have found a dino! Long story) Thankyou all who have replied. An intercom type arrangement would make sense - the aircraft was a two seater. Would that sort of beam approach still be in use long after the war? and why would a switch differentiate between 'SBA' and VHF SBA? More digging to do... Thanks for the ideas... __________________ Real radios glow in the dark M6GLD