Marconi 55 - UK Vintage Radio Repair and Restoration Discussion Forum

jgj6331 · 22nd Oct 2007, 7:36 pm

I have acquired a Marconi 55 and need some information on this set. I would also like to operate it, but I am unfamiliar with some of the terminology - "H.T., G.B.,Low tension accumulator, etc." What will I need to properly operate this radio? Is this radio of any value? Thanks...

Station X · 22nd Oct 2007, 7:44 pm

You can get the Service Sheet for this model by clicking the link at the top right of this page. It's listed as a Marconiphone 55.

paulsherwin · 22nd Oct 2007, 7:44 pm

HT = High Tension = B battery
Low Tension Accumulator = A battery
GB = Grid Bias - I think this is a C battery in American usage.

Sorry, I don't know the radio.

Paul

mickjjo · 22nd Oct 2007, 7:58 pm

The Marconi 55 dates from 1929 so should have a reasonable value if in original condition:-

http://www.radiomuseum.org/r/marconi...iphone_55.html

Regards, Mick.

jgj6331 · 22nd Oct 2007, 9:53 pm

Thanks for the replies... A followup - what voltage would be used for the 'low tension accumulator' ? I am not knowledgeable of the filament requirements of Marconi Valves. The other required voltages are indicated in a diagram on the inside back of the radio and can be supplied by my homebrew voltage adapter.

mickjjo · 23rd Oct 2007, 10:19 am

The standard low tension voltage for this period was 2 volts, that of one lead-acid cell, The valve type numbers would give a clue.

Regards, Mick.

jgj6331 · 23rd Oct 2007, 2:41 pm

The 5 valve line-up includes: P215, L210, ? HL2/C, HL210(x2)... The ?HL2/C is not labelled directly (perhaps worn off) but shown on the diagram in the back where there may be a typographical error... Thanks.

jgj6331 · 24th Oct 2007, 8:50 pm

I lashed up the Marconi with a power supply and it does work - I received a few local stations during the day and even the 'Grand Old Opery' in Nashville at night - station WSM - about 500km away. I would imagine it's the first time this radio has wailed about with country music. The MW range is limited and not much over here in LW but airport beacons and such. Is LW still used for commercial radio in EU?

I would like to build up a battery assembly to use in it - the HT will be easy to make up with 9v batteries and the GB with 1.5v torch cells. We really don't have a 2v cell - perhaps I can adjust 3v with a proper resistor or rheostat.

The battery wires are somewhat ruined and will have to be replaced - unfortunately, the rubber-coated wire is not readily available here and I'll probably have to make do with similar plastic coated wire.

mickjjo · 24th Oct 2007, 9:13 pm

Well done for getting it working! A suitable modern equivalent for the 2 volt accumulator would be one of these "Cyclon" 2 volt cells, available in various capacities:-

http://www.enersysreservepower.com/s...p?routine=scpf

Regards, Mick.

Radio_Dave · 25th Oct 2007, 11:13 am

Quote:

Originally Posted by jgj6331

I would like to build up a battery assembly to use in it - the HT will be easy to make up with 9v batteries and the GB with 1.5v torch cells.

I have some images of Ever Ready HT and GB batteries, that can be printed out and made into replicas. PM me your email address if you want them

David

Nickthedentist · 25th Oct 2007, 12:44 pm

Quote:

Originally Posted by jgj6331

The battery wires are somewhat ruined and will have to be replaced - unfortunately, the rubber-coated wire is not readily available here and I'll probably have to make do with similar plastic coated wire.

Silicone-insulated wire looks and feels similar and is fairly readily available, apparently in a range of colours, from RS etc.

22nd Oct 2007, 7:36 pm	#1
jgj6331 Retired Dormant Member Join Date: Oct 2007 Location: Macon, Georgia, USA. Posts: 30	Marconi 55 I have acquired a Marconi 55 and need some information on this set. I would also like to operate it, but I am unfamiliar with some of the terminology - "H.T., G.B.,Low tension accumulator, etc." What will I need to properly operate this radio? Is this radio of any value? Thanks...

22nd Oct 2007, 7:44 pm	#2
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Marconi 55 You can get the Service Sheet for this model by clicking the link at the top right of this page. It's listed as a Marconiphone 55. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

22nd Oct 2007, 7:44 pm	#3
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,970	Re: Marconi 55 HT = High Tension = B battery Low Tension Accumulator = A battery GB = Grid Bias - I think this is a C battery in American usage. Sorry, I don't know the radio. Paul

22nd Oct 2007, 7:58 pm	#4
mickjjo Rest in Peace Join Date: Jul 2004 Location: Dartford, Kent, UK. Posts: 1,661	Re: Marconi 55 The Marconi 55 dates from 1929 so should have a reasonable value if in original condition:- http://www.radiomuseum.org/r/marconi...iphone_55.html Regards, Mick.

22nd Oct 2007, 9:53 pm	#5
jgj6331 Retired Dormant Member Join Date: Oct 2007 Location: Macon, Georgia, USA. Posts: 30	Re: Marconi 55 Thanks for the replies... A followup - what voltage would be used for the 'low tension accumulator' ? I am not knowledgeable of the filament requirements of Marconi Valves. The other required voltages are indicated in a diagram on the inside back of the radio and can be supplied by my homebrew voltage adapter.

23rd Oct 2007, 10:19 am	#6
mickjjo Rest in Peace Join Date: Jul 2004 Location: Dartford, Kent, UK. Posts: 1,661	Re: Marconi 55 The standard low tension voltage for this period was 2 volts, that of one lead-acid cell, The valve type numbers would give a clue. Regards, Mick.

23rd Oct 2007, 2:41 pm	#7
jgj6331 Retired Dormant Member Join Date: Oct 2007 Location: Macon, Georgia, USA. Posts: 30	Re: Marconi 55 The 5 valve line-up includes: P215, L210, ? HL2/C, HL210(x2)... The ?HL2/C is not labelled directly (perhaps worn off) but shown on the diagram in the back where there may be a typographical error... Thanks.

24th Oct 2007, 8:50 pm	#8
jgj6331 Retired Dormant Member Join Date: Oct 2007 Location: Macon, Georgia, USA. Posts: 30	Re: Marconi 55 I lashed up the Marconi with a power supply and it does work - I received a few local stations during the day and even the 'Grand Old Opery' in Nashville at night - station WSM - about 500km away. I would imagine it's the first time this radio has wailed about with country music. The MW range is limited and not much over here in LW but airport beacons and such. Is LW still used for commercial radio in EU? I would like to build up a battery assembly to use in it - the HT will be easy to make up with 9v batteries and the GB with 1.5v torch cells. We really don't have a 2v cell - perhaps I can adjust 3v with a proper resistor or rheostat. The battery wires are somewhat ruined and will have to be replaced - unfortunately, the rubber-coated wire is not readily available here and I'll probably have to make do with similar plastic coated wire.

24th Oct 2007, 9:13 pm	#9
mickjjo Rest in Peace Join Date: Jul 2004 Location: Dartford, Kent, UK. Posts: 1,661	Re: Marconi 55 Well done for getting it working! A suitable modern equivalent for the 2 volt accumulator would be one of these "Cyclon" 2 volt cells, available in various capacities:- http://www.enersysreservepower.com/s...p?routine=scpf Regards, Mick.