Cartridge used in BSR UA6? - UK Vintage Radio Repair and Restoration Discussion Forum

'LIVEWIRE?' · 18th Mar 2018, 11:42 am

The UA6 in question is from a Westminster Radiogram, and the(almost certainly faulty) mono crystal cartridge fitted appears to be an Acos turnover type. Fortunately it's mounted in a standard bracket with 0.5" centers, and the P.U. Head is quite wide, so almost any cartridge will fit, but I don't know what the output of the original was. Can anyone confirm that the cartridge is, in fact, an Acos, and tell me what it's output would have been? No model number on the P.U. I'm afraid, just a logo and 'Made in England'

vidjoman · 18th Mar 2018, 12:20 pm

A picture would help. It may not be the original and even if it is, different cartridges might be fitted by different radiogram manufacturers.

Edward Huggins · 18th Mar 2018, 1:11 pm

Typically the BSR UA6 would be fitted with an Acos "Hi G" turnover crystal cartridge.
The type number HGP 37(or 9)-1 comes to mind. Given it would have been feeding a 2 stage Radiogram amplifier, it's output would have been around 400mV.

'LIVEWIRE?' · 18th Mar 2018, 2:44 pm

You're probably right, Edward. I'll take and post a picture later. As I noted, there's no model No. visible. There is a matching/attenuating network in series with the cartridge, but I haven't sketched out the circuit of that.

Edward Huggins · 18th Mar 2018, 4:42 pm

The R/C network might have been to tame the output of the Acos cartridge to a more manageable 250mV for the 1st AF stage - maybe an EBC41.

'LIVEWIRE?' · 19th Mar 2018, 6:38 pm

The 1st. A.F. stage, like all the valves in the radiogram (except the 'magic-eye', which is Octal) is a B9A valve-an EABC80 is the detector/1st. A.F. amp., followed by an EL84, but , that aside, Edward, you are correct.

18th Mar 2018, 11:42 am	#1
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Cartridge used in BSR UA6? The UA6 in question is from a Westminster Radiogram, and the(almost certainly faulty) mono crystal cartridge fitted appears to be an Acos turnover type. Fortunately it's mounted in a standard bracket with 0.5" centers, and the P.U. Head is quite wide, so almost any cartridge will fit, but I don't know what the output of the original was. Can anyone confirm that the cartridge is, in fact, an Acos, and tell me what it's output would have been? No model number on the P.U. I'm afraid, just a logo and 'Made in England'

18th Mar 2018, 12:20 pm	#2
vidjoman Dekatron Join Date: Jun 2013 Location: East Sussex, UK. Posts: 3,326	Re: Cartridge used in BSR UA6? A picture would help. It may not be the original and even if it is, different cartridges might be fitted by different radiogram manufacturers.

18th Mar 2018, 1:11 pm	#3
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,336	Re: Cartridge used in BSR UA6? Typically the BSR UA6 would be fitted with an Acos "Hi G" turnover crystal cartridge. The type number HGP 37(or 9)-1 comes to mind. Given it would have been feeding a 2 stage Radiogram amplifier, it's output would have been around 400mV. __________________ Edward.

18th Mar 2018, 2:44 pm	#4
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: Cartridge used in BSR UA6? You're probably right, Edward. I'll take and post a picture later. As I noted, there's no model No. visible. There is a matching/attenuating network in series with the cartridge, but I haven't sketched out the circuit of that.

18th Mar 2018, 4:42 pm	#5
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,336	Re: Cartridge used in BSR UA6? The R/C network might have been to tame the output of the Acos cartridge to a more manageable 250mV for the 1st AF stage - maybe an EBC41. __________________ Edward.

19th Mar 2018, 6:38 pm	#6
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: Cartridge used in BSR UA6? The 1st. A.F. stage, like all the valves in the radiogram (except the 'magic-eye', which is Octal) is a B9A valve-an EABC80 is the detector/1st. A.F. amp., followed by an EL84, but , that aside, Edward, you are correct.