G.E.C. shortwave tube receiver - UK Vintage Radio Repair and Restoration Discussion Forum

Francesco Nardi · 18th Mar 2022, 11:40 am

Good morning everyone,
I am looking for information on this receiver (even just schematic diagram).
It is probably an aeronautical receiver, it works, but I would like to restructure and align it.

Thank you so much

Francesco Nardi

HamishBoxer · 18th Mar 2022, 12:18 pm

Welcome Francesco, a very nice find and one I do not recognise.

Radio Wrangler · 18th Mar 2022, 12:34 pm

Coverage stopping at 20MHz fits with it being aeronautical. It's not a receiver I recognise.

David

turretslug · 18th Mar 2022, 6:21 pm

Hi Francesco and welcome. That's an interesting looking set- I suppose the most familiar aviation radios around are the ones produced in huge numbers during WW2 and dumped on the surplus market, so seeing what looks like a 1950s design that would have been made in much smaller numbers makes for a change. I wonder if the large black object is a transformer associated with a vibrator, or possibly even early germanium power transistors? Looks as though there is something like a 5Y3GT or 5Z4GT rectifier nearby.

The unlabelled small knob with a white dot underneath the pitch control looks like one of the relatively modern miniature integrated "knob-pots", maybe someone had added a manual HF gain control or something like that. With just three-gang tuning and a minimum received frequency of 2MHz, the IF could be relatively high, around 1.6-1.8MHz. It's striking that the valve locations are marked with GEC's consumer valve designations, rather than their CV13x or CV40xx professional-usage codes as might be expected with avionics equipment, whether military or civil.

Good luck with finding information about it, but I suspect that there are no big surprises in the circuitry,

Colin

Silicon · 18th Mar 2022, 7:59 pm

The control knobs look similar to those on the GEC BRT 400 receiver.

That may help to date it.

Are there any date codes on the large capacitors?

CambridgeWorks · 18th Mar 2022, 8:08 pm

Sorry, cannot help either.
I really love your receiver. I just wish we had them available over here.
It looks to be excellent quality build and should I think work very well, when you get it going.
Best of luck with your project.
Rob

Francesco Nardi · 18th Mar 2022, 10:42 pm

Thank you all for your interventions.
I have found that the two jacks and the knob with white dot are not connected, they probably only serve to close the holes.
There is no reference, date or other element to be able to recognize this.
Hope someone knows the model.
They can't have built just one!

G3PIJpeter · 20th Mar 2022, 11:26 pm

Quote:

Originally Posted by Francesco Nardi

There is no reference, date or other element to be able to recognize this.

The TCC Visconol capacitor has a date on it: Oct 52 - or is it 62? A decade makes quite a difference.
Peter

gm0ekm cecil · 30th Mar 2022, 1:54 pm

It must have had an associated transmitter, hence the two relays.

18th Mar 2022, 11:40 am	#1
Francesco Nardi Diode Join Date: Mar 2022 Location: Gaeta, Italy. Posts: 2	G.E.C. shortwave tube receiver Good morning everyone, I am looking for information on this receiver (even just schematic diagram). It is probably an aeronautical receiver, it works, but I would like to restructure and align it. Thank you so much Francesco Nardi Attached Thumbnails

18th Mar 2022, 12:18 pm	#2
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: G.E.C. shortwave tube receiver Welcome Francesco, a very nice find and one I do not recognise. __________________ G8JET BVWS Archivist and Member V.M.A.R.S

18th Mar 2022, 12:34 pm	#3
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,867	Re: G.E.C. shortwave tube receiver Coverage stopping at 20MHz fits with it being aeronautical. It's not a receiver I recognise. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

18th Mar 2022, 6:21 pm	#4
turretslug Dekatron Join Date: Nov 2011 Location: Surrey, UK. Posts: 4,394	Re: G.E.C. shortwave tube receiver Hi Francesco and welcome. That's an interesting looking set- I suppose the most familiar aviation radios around are the ones produced in huge numbers during WW2 and dumped on the surplus market, so seeing what looks like a 1950s design that would have been made in much smaller numbers makes for a change. I wonder if the large black object is a transformer associated with a vibrator, or possibly even early germanium power transistors? Looks as though there is something like a 5Y3GT or 5Z4GT rectifier nearby. The unlabelled small knob with a white dot underneath the pitch control looks like one of the relatively modern miniature integrated "knob-pots", maybe someone had added a manual HF gain control or something like that. With just three-gang tuning and a minimum received frequency of 2MHz, the IF could be relatively high, around 1.6-1.8MHz. It's striking that the valve locations are marked with GEC's consumer valve designations, rather than their CV13x or CV40xx professional-usage codes as might be expected with avionics equipment, whether military or civil. Good luck with finding information about it, but I suspect that there are no big surprises in the circuitry, Colin

18th Mar 2022, 7:59 pm	#5
Silicon Nonode Join Date: Jun 2007 Location: Coulsdon, London, UK. Posts: 2,163	Re: G.E.C. shortwave tube receiver The control knobs look similar to those on the GEC BRT 400 receiver. That may help to date it. Are there any date codes on the large capacitors?

18th Mar 2022, 8:08 pm	#6
CambridgeWorks Nonode Join Date: Jun 2010 Location: Spalding, Peterborough, Cambridgeshire, UK. Posts: 2,858	Re: G.E.C. shortwave tube receiver Sorry, cannot help either. I really love your receiver. I just wish we had them available over here. It looks to be excellent quality build and should I think work very well, when you get it going. Best of luck with your project. Rob __________________ Apprehension creeping like a tube train up your spine - Cymbaline. Film More soundtrack - Pink Floyd

18th Mar 2022, 10:42 pm	#7
Francesco Nardi Diode Join Date: Mar 2022 Location: Gaeta, Italy. Posts: 2	Re: G.E.C. shortwave tube receiver Thank you all for your interventions. I have found that the two jacks and the knob with white dot are not connected, they probably only serve to close the holes. There is no reference, date or other element to be able to recognize this. Hope someone knows the model. They can't have built just one!

30th Mar 2022, 1:54 pm	#9
gm0ekm cecil Tetrode Join Date: Jan 2008 Location: Shetland, UK. Posts: 79	Re: G.E.C. shortwave tube receiver It must have had an associated transmitter, hence the two relays.