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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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18th May 2008, 9:13 pm | #1 |
Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
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Brown Type F headphones
I have got a good pair of working black bakelite types which read 3.52 K across leads and 1.75 K across each phone so they are in series .On the back is a sort of scratch mark or glue spot .Did these have a metal label with the measured IMpedance or would the maker remove the 4000 Ohm claim if they did not come up to scratch?Can anyone tell the approx. date .They have short metal pins on the end.
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18th May 2008, 10:18 pm | #2 |
Rest in Peace
Join Date: Jul 2004
Location: Dartford, Kent, UK.
Posts: 1,661
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Re: Brown Type F headphones
There is some information about SG Brown "F" headphones here:-
http://www.vintageradio.nl/Diversen/...e_f_engels.htm http://www.richardsradios.co.uk/sgbrown.html They seem to have had a long production run. Regards, Mick. |
19th May 2008, 1:49 pm | #3 |
Octode
Join Date: Aug 2003
Location: Welwyn Garden City, Herts. UK.
Posts: 1,906
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Re: Brown Type F headphones
The impedance was 4k per phone the resistance was lower
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23rd May 2008, 3:35 pm | #4 |
Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
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Re: Brown Type F headphones
Mine were the later 50's black bakelite type but without the white 2000 Ohms on the back,just this odd grey area where label might have been .It is slightly recessed and on all 4 headphones.Yes a photo would be better -coming soon.
What would be a safe maximum voltage or wattage to use these with .I am only considering a very low Amp onto a crystal receiver but dont want to damage them. |
3rd Jun 2008, 5:58 pm | #5 |
Octode
Join Date: Jun 2005
Location: Sheffield, South Yorkshire, UK.
Posts: 1,227
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Re: Brown Type F headphones
I finally took a photo
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