Graves Vulcan II what valves and aerial should be used - UK Vintage Radio Repair and Restoration Discussion Forum

jukeboxjunkie · 22nd Aug 2009, 4:45 pm

I have a circuit diagram of this set but the valves are not listed. The set currently has two valves fitted: PM2 and PM2DX but from other data collected I see that PM1 and PM2 are used. Can anyone help with the information about the correct valves to be used as I want to get this set working and not just display?

Also I would like to construct or buy the correct type of aerial to use with it.

Many thanks for any help offered.

Steve.

Steve_P · 22nd Aug 2009, 7:07 pm

There's an article about it up top there. It says PM1HF and PM2.

I think it just has a very long piece of wire for an aerial and earth to a spike in the ground.

Cheers,

Steve P.

murphyv310 · 22nd Aug 2009, 8:20 pm

Hi
As Steve says a long wire aerial is the best, also a good earth should be used, preferably one that has an earth spike driven into the ground, radiators and the mains earth should be avoided due to electrical noise.
20's & 30's TRF radios sometimes had an accessory that looked like a cardboard tube that was a variable capacitor it would increase or decrease the coupling from the long wire aerial.
Regarding valves I have found that virtually any 2 volt filament valve will work some better some worse than others, these valves never seem to go duff unless actually broken. You may have more trouble with chokes and interstage transformers, these can go O/C due to green spot.
Cheers
Trevor

jukeboxjunkie · 23rd Aug 2009, 10:51 am

Thanks Steve and Trevor. So is there any particular length and type of wire to use for the aerial, should it be insulated? I assume I would use some sort of insulator at both ends and attach a wire one end to the radio. What about lightning? Also I assume the HT voltage should be 90 volts but I see some sets work at a lower voltage,60 volts? The grid battery is 4.5 volts I think and heater 2 volts?

HamishBoxer · 23rd Aug 2009, 11:38 am

Re Lightning,just connect the aerial to the earth in case of a near storm.

David

HamishBoxer · 23rd Aug 2009, 11:40 am

PS Yes use insulators either end ,pot or plastic egg or ribbed are ok

AC/HL · 23rd Aug 2009, 10:49 pm

Keep a look out for any early wireless books, they're quite common at proper bookshops (not W H Smiths or other large chains). They all feature articles on aerials/earths etc,

22nd Aug 2009, 4:45 pm	#1
jukeboxjunkie Retired Dormant Member Join Date: Jun 2009 Location: Coventry Posts: 38	Graves Vulcan II what valves and aerial should be used I have a circuit diagram of this set but the valves are not listed. The set currently has two valves fitted: PM2 and PM2DX but from other data collected I see that PM1 and PM2 are used. Can anyone help with the information about the correct valves to be used as I want to get this set working and not just display? Also I would like to construct or buy the correct type of aerial to use with it. Many thanks for any help offered. Steve.

22nd Aug 2009, 7:07 pm	#2
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Graves Vulcan II what valves and aerial should be used There's an article about it up top there. It says PM1HF and PM2. I think it just has a very long piece of wire for an aerial and earth to a spike in the ground. 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...?

22nd Aug 2009, 8:20 pm	#3
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Graves Vulcan II what valves and aerial should be used Hi As Steve says a long wire aerial is the best, also a good earth should be used, preferably one that has an earth spike driven into the ground, radiators and the mains earth should be avoided due to electrical noise. 20's & 30's TRF radios sometimes had an accessory that looked like a cardboard tube that was a variable capacitor it would increase or decrease the coupling from the long wire aerial. Regarding valves I have found that virtually any 2 volt filament valve will work some better some worse than others, these valves never seem to go duff unless actually broken. You may have more trouble with chokes and interstage transformers, these can go O/C due to green spot. Cheers Trevor __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

23rd Aug 2009, 10:51 am	#4
jukeboxjunkie Retired Dormant Member Join Date: Jun 2009 Location: Coventry Posts: 38	Re: Graves Vulcan II what valves and aerial should be used Thanks Steve and Trevor. So is there any particular length and type of wire to use for the aerial, should it be insulated? I assume I would use some sort of insulator at both ends and attach a wire one end to the radio. What about lightning? Also I assume the HT voltage should be 90 volts but I see some sets work at a lower voltage,60 volts? The grid battery is 4.5 volts I think and heater 2 volts?

23rd Aug 2009, 11:38 am	#5
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Graves Vulcan II what valves and aerial should be used Re Lightning,just connect the aerial to the earth in case of a near storm. David

23rd Aug 2009, 11:40 am	#6
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Graves Vulcan II what valves and aerial should be used PS Yes use insulators either end ,pot or plastic egg or ribbed are ok

23rd Aug 2009, 10:49 pm	#7
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Graves Vulcan II what valves and aerial should be used Keep a look out for any early wireless books, they're quite common at proper bookshops (not W H Smiths or other large chains). They all feature articles on aerials/earths etc,