Early valve data/characteristics? - UK Vintage Radio Repair and Restoration Discussion Forum

thevalveset · 5th Jun 2018, 2:29 pm

Hi everyone

I am in the throws of completing an exact replica of a Gecophone BC2001 1922 era wireless receiver.
I have re-manufactured EVERY last part including valve holders, filament rheostat, variable condenser, fixed telephone condensers, knobs....in fact everything but the valves!
I plan not only to have the receiver look exactly as original, but have it fully working and receiving M.W. stations when I demonstrate it at my local Radio Club.
As the wireless is a TRF I have been experimenting with the amount of 'reaction' required to 'smoothly' control the operation of the set.
The original receiver used Type 'R' bright emitter valves, whereas I am substituting 2V battery valves when operating the receiver for demonstration.

However this prompted me to wonder about the characteristics of these 'R types' compared to the slightly later 2V battery valves.
Whilst I can find plenty of data/characteristic curves for the likes of PM1HF's and 210HL's I have failed to find any data on 'bright emitters'.

Was any such data ever measured/published and if so where can I find it.

Thanks in anticipation
Dave

Nuvistor · 5th Jun 2018, 2:37 pm

Some data on bright emmiters, if not suitable search those sites, they have lots of valve info.

http://www.r-type.org/articles/art-095.htm

http://www.r-type.org/exhib/aaa0119.htm

https://www.radiomuseum.org/tubes/tube_210hl.html

barrymagrec · 5th Jun 2018, 2:59 pm

Make your own :

https://www.youtube.com/watch?v=EzyXMEpq4qw

G6Tanuki · 5th Jun 2018, 4:50 pm

Remember that in the 1920s it was normal to vary the filament-voltage of RF-amp and detector valves using a rheostat in series with the valve in order to control the gain - I guess any published curves will be for the filament running at full rated voltage.

mark_in_manc · 5th Jun 2018, 4:53 pm

Wow. Thanks for posting that. As Ian Drury once sang, There Aint Half Been Some Clever B*******

AC/HL · 5th Jun 2018, 8:00 pm

I understand that the early R valves were a bit variable, but that ones just a tad soft were prized for their higher gain.

Mr Moose · 5th Jun 2018, 9:59 pm

Hello,
There is a article on page 97 of Experimental Wireless for November 1923 http://www.americanradiohistory.com/...ss-1923-11.pdf on the characteristics of the dull emitter valves which were replacing the bright emitters at the time.
It includes information on the DER valve which is the dull emitter equivalent of the R-type but with a lower filament voltage. The DER valve has a thoriated tungsten filament so would still run much hotter than the coated filaments of the Mullard PM series etc.
Yours, Richard

5th Jun 2018, 2:29 pm	#1
thevalveset Tetrode Join Date: Oct 2007 Location: Nottingham, Nottinghamshire, UK. Posts: 73	Early valve data/characteristics? Hi everyone I am in the throws of completing an exact replica of a Gecophone BC2001 1922 era wireless receiver. I have re-manufactured EVERY last part including valve holders, filament rheostat, variable condenser, fixed telephone condensers, knobs....in fact everything but the valves! I plan not only to have the receiver look exactly as original, but have it fully working and receiving M.W. stations when I demonstrate it at my local Radio Club. As the wireless is a TRF I have been experimenting with the amount of 'reaction' required to 'smoothly' control the operation of the set. The original receiver used Type 'R' bright emitter valves, whereas I am substituting 2V battery valves when operating the receiver for demonstration. However this prompted me to wonder about the characteristics of these 'R types' compared to the slightly later 2V battery valves. Whilst I can find plenty of data/characteristic curves for the likes of PM1HF's and 210HL's I have failed to find any data on 'bright emitters'. Was any such data ever measured/published and if so where can I find it. Thanks in anticipation Dave

5th Jun 2018, 2:37 pm	#2
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Early valve data/characteristics? Some data on bright emmiters, if not suitable search those sites, they have lots of valve info. http://www.r-type.org/articles/art-095.htm http://www.r-type.org/exhib/aaa0119.htm https://www.radiomuseum.org/tubes/tube_210hl.html __________________ Frank

5th Jun 2018, 2:59 pm	#3
barrymagrec Octode Join Date: Dec 2017 Location: Morden, Surrey, UK. Posts: 1,558	Re: Early valve data/characteristics? Make your own : https://www.youtube.com/watch?v=EzyXMEpq4qw

5th Jun 2018, 4:50 pm	#4
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,998	Re: Early valve data/characteristics? Remember that in the 1920s it was normal to vary the filament-voltage of RF-amp and detector valves using a rheostat in series with the valve in order to control the gain - I guess any published curves will be for the filament running at full rated voltage.

5th Jun 2018, 4:53 pm	#5
mark_in_manc Octode Join Date: Nov 2011 Location: Manchester, UK. Posts: 1,874	Re: Early valve data/characteristics? Wow. Thanks for posting that. As Ian Drury once sang, There Aint Half Been Some Clever B*******

5th Jun 2018, 8:00 pm	#6
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Early valve data/characteristics? I understand that the early R valves were a bit variable, but that ones just a tad soft were prized for their higher gain.

5th Jun 2018, 9:59 pm	#7
Mr Moose Octode Join Date: Jul 2008 Location: Gloucestershire, UK. Posts: 1,043	Re: Early valve data/characteristics? Hello, There is a article on page 97 of Experimental Wireless for November 1923 http://www.americanradiohistory.com/...ss-1923-11.pdf on the characteristics of the dull emitter valves which were replacing the bright emitters at the time. It includes information on the DER valve which is the dull emitter equivalent of the R-type but with a lower filament voltage. The DER valve has a thoriated tungsten filament so would still run much hotter than the coated filaments of the Mullard PM series etc. Yours, Richard Last edited by Mr Moose; 5th Jun 2018 at 10:08 pm.