Some advice please re external aerials. - UK Vintage Radio Repair and Restoration Discussion Forum

traveller · 26th Feb 2008, 6:49 pm

Hello, Ive had a few old radios before, such as a Bush dac90, but none that needed a separate ariel. Ive recently been given a Bush sug91 and would like to know what sort of ariel it needs and about earthing it.

The set has been unused for many years, Ive blown it out with an airline and removed each valve and cleaned them, then put the whole lot in the airing cupboard for a few days to make sure all was dry. The set lights up as do the valves. The only noise is sort of interference?

Any advice would be greatly appreciated.

Dave

Ian - G4JQT · 27th Feb 2008, 3:53 pm

Just a few feet of wire (5 to 10) connected to the aerial socket and draped around a window should bring in a few stations if your radio is working properly. ANY wire will do for an aerial, but the easiest to use is multi-stranded single-core wire.

Just to get things started you can even connect the TV aerial coax cable to it - connect the braid/screen to the radio aerial connection with a croc clip.

If you want a proper aerial, then 20 to 50 feet of wire suspended outside and clear of objects and brought in to the house by the shortest route will be more than adequate. Do a Google search if you are unsure. http://members.aol.com/djadamson7/ar.../antenna1.html gave an elaborate set up, but gives the idea. If you search using terms like: crystal set aerial earth wire antenna… you should find all you need.

The earth is not quite as important as an aerial, but a good connection to a cold water or radiator pipe will do. ONLY EARTH if there is an earth SOCKET on the set. I'm not sure if the SUG91 is a live chassis set or not (probably is) so connecting the chassis to directly to earth is fraught with problems or even dangers.

Live chassis sets that are designed to be earthed will have an isolating capacitor from the chassis to the earth connection. This may be leaky so should be replaced with a modern X- or Y-class capacitor of the same value.

I don't suggest you connect the mains earth to the earth connection, as it will probably be full of mains-borne interference, though worth a try if all else fails.

If your set still doesn’t work (and I think you should get at least some stations very weakly even without any aerial or earth), then I'm sure we can help you via this forum.

Ian

Steve_P · 27th Feb 2008, 4:04 pm

Ian's right about Aerials of course, but if a radio has been unused for so long, and it's this old, then chances are that a number of parts (capacitors mainly) will be really past their best. So much so that you need to check the set over thouroughly.

C24 would be an obvious choice! If this goes short circuit, it could cause Distortion, A blown output valve (replaceable) or a damaged O/P transformer (Difficult!).

The circuit should be available top right!

Cheers,

Steve P

paulsherwin · 27th Feb 2008, 4:14 pm

If the set is indeed an AC/DC set (I haven't checked) there will be safety critical capacitors isolating the aerial and earth sockets. These *must* be replaced with modern HV plastic film caps, preferably Y rated, failing that X2 rated. If you don't do this, the set will be *dangerous*.

As others have said, a couple of metres of wire hanging out of the back should be enough to pull in a few strong local stations on MW and it will also work on SW. LW generally needs a much longer length of wire for good results but given your location you may get RTE1 252kHz LW even with a few feet of wire.

If the radio has no internal aerial (frame or ferrite rod) and you don't have any external aerial connected at all, the radio will just produce mush.

Paul

Steve_P · 27th Feb 2008, 4:40 pm

It does not have an internal aerial Paul. And it is an Auto Transformer System.

The caps you mention are C1, C2 and C4. I might also change C28!!

Cheers,

Steve P

26th Feb 2008, 6:49 pm	#1
traveller Retired Dormant Member Join Date: Feb 2008 Location: Co. Antrim Posts: 1	Some advice please re external aerials. Hello, Ive had a few old radios before, such as a Bush dac90, but none that needed a separate ariel. Ive recently been given a Bush sug91 and would like to know what sort of ariel it needs and about earthing it. The set has been unused for many years, Ive blown it out with an airline and removed each valve and cleaned them, then put the whole lot in the airing cupboard for a few days to make sure all was dry. The set lights up as do the valves. The only noise is sort of interference? Any advice would be greatly appreciated. Dave

27th Feb 2008, 3:53 pm	#2
Ian - G4JQT Octode Join Date: Jun 2004 Location: Reading/Fakenham, UK. Posts: 1,324	Re: Some advice please re external aerials. Just a few feet of wire (5 to 10) connected to the aerial socket and draped around a window should bring in a few stations if your radio is working properly. ANY wire will do for an aerial, but the easiest to use is multi-stranded single-core wire. Just to get things started you can even connect the TV aerial coax cable to it - connect the braid/screen to the radio aerial connection with a croc clip. If you want a proper aerial, then 20 to 50 feet of wire suspended outside and clear of objects and brought in to the house by the shortest route will be more than adequate. Do a Google search if you are unsure. http://members.aol.com/djadamson7/ar.../antenna1.html gave an elaborate set up, but gives the idea. If you search using terms like: crystal set aerial earth wire antenna… you should find all you need. The earth is not quite as important as an aerial, but a good connection to a cold water or radiator pipe will do. ONLY EARTH if there is an earth SOCKET on the set. I'm not sure if the SUG91 is a live chassis set or not (probably is) so connecting the chassis to directly to earth is fraught with problems or even dangers. Live chassis sets that are designed to be earthed will have an isolating capacitor from the chassis to the earth connection. This may be leaky so should be replaced with a modern X- or Y-class capacitor of the same value. I don't suggest you connect the mains earth to the earth connection, as it will probably be full of mains-borne interference, though worth a try if all else fails. If your set still doesn’t work (and I think you should get at least some stations very weakly even without any aerial or earth), then I'm sure we can help you via this forum. Ian Last edited by Ian - G4JQT; 27th Feb 2008 at 4:00 pm.

27th Feb 2008, 4:04 pm	#3
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Some advice please re external aerials. Ian's right about Aerials of course, but if a radio has been unused for so long, and it's this old, then chances are that a number of parts (capacitors mainly) will be really past their best. So much so that you need to check the set over thouroughly. C24 would be an obvious choice! If this goes short circuit, it could cause Distortion, A blown output valve (replaceable) or a damaged O/P transformer (Difficult!). The circuit should be available top right! Cheers, Steve P __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

27th Feb 2008, 4:14 pm	#4
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,960	Re: Some advice please re external aerials. If the set is indeed an AC/DC set (I haven't checked) there will be safety critical capacitors isolating the aerial and earth sockets. These must be replaced with modern HV plastic film caps, preferably Y rated, failing that X2 rated. If you don't do this, the set will be dangerous. As others have said, a couple of metres of wire hanging out of the back should be enough to pull in a few strong local stations on MW and it will also work on SW. LW generally needs a much longer length of wire for good results but given your location you may get RTE1 252kHz LW even with a few feet of wire. If the radio has no internal aerial (frame or ferrite rod) and you don't have any external aerial connected at all, the radio will just produce mush. Paul

27th Feb 2008, 4:40 pm	#5
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Some advice please re external aerials. It does not have an internal aerial Paul. And it is an Auto Transformer System. The caps you mention are C1, C2 and C4. I might also change C28!! Cheers, Steve P __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?