UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Telephony and Telecomms

Notices

Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment

Closed Thread
 
Thread Tools
Old 29th Mar 2018, 11:33 am   #1
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Is it possible to get more receiver volume from BT Statesman and Viscount phones ?

I'm planning to convert one or the other to binaural headset use but so far I find the earphone volume isn't really sufficient for two 300 ohm earphones. Apart from adding a battery-powered inline amplifier is it feasible, for example, to remove or replace some components from the circuit board ? Would something like that help ?

All suggestions gratefully read. Thankyou.
Sparks is offline  
Old 29th Mar 2018, 3:45 pm   #2
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,684
Default Re: Is it possible to get more receiver volume from BT Statesman and Viscount phones

Quote:
Originally Posted by Sparks View Post
I'm planning to convert one or the other to binaural headset use but so far I find the earphone volume isn't really sufficient for two 300 ohm earphones.
When you say 'binaural' do you mean each headset receiver is connected to something different? The 'new' type of inset receiver in the Statesman or Ambassador has an impedance of typically 462 Ohms at 1kHz so is a lot higher than the traditional kind. Are you replacing the handset receiver inset with the headset or are you planning on running the handset as well?

You could use a matching transformer (or transformers) to adjust the impedance to your headset, but you'd need to find them small enough to fit in your phone.
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline  
Old 29th Mar 2018, 5:09 pm   #3
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Re: Is it possible to get more receiver volume from BT Statesman and Viscount phones

Russell, the plan is to simply use the circuit board of whichever phone, so no handset or keypad and a BT1000 lever key as a hook switch. The headset has two 300 ohm rocking armature earphones wired in parallel and a dynamic microphone, altogether replacing the handset.
Sparks is offline  
Old 29th Mar 2018, 6:33 pm   #4
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,684
Default Re: Is it possible to get more receiver volume from BT Statesman and Viscount phones

Try the receivers in series before considering other options to see if that makes an improvement.
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline  
Old 29th Mar 2018, 9:16 pm   #5
OscarFoxtrot
Heptode
 
OscarFoxtrot's Avatar
 
Join Date: Apr 2011
Location: Edinburgh, UK.
Posts: 805
Default Re: Is it possible to get more receiver volume from BT Statesman and Viscount phones

The circuits used in amplifying handsets and powered from the carbon transmitter voltage may give you some inspiration

http://www.samhallas.co.uk/repositor...1000/N1840.pdf

http://www.samhallas.co.uk/repositor...1000/N1842.pdf

http://www.samhallas.co.uk/collectio...3_variants.htm
OscarFoxtrot is offline  
Old 30th Mar 2018, 11:16 am   #6
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Re: Is it possible to get more receiver volume from BT Statesman and Viscount phones

I just happen to own one of those amplifier circuits from the old GPO handsets. The snag is that they are powered by the same source as the carbon transmitter on a type 746. The Statesman and Viscount don't have that power provision.

Ideally I was hoping for a solution along the lines of removing or replacing a resistor in the receiver circuit to boost the volume.

Thankyou for your responses folks.
Sparks is offline  
Old 30th Mar 2018, 11:47 am   #7
Nickthedentist
Dekatron
 
Nickthedentist's Avatar
 
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,820
Default Re: Is it possible to get more receiver volume from BT Statesman and Viscount phones

Seems a shame to spoil a Statesman or Viscount with no guarantee of success.

I could send you a BT Relate 300 phone with loudspeaking provision (powered by AA batteries) FOC if you wish - it came from moderator Graham originally. The display's on the way out but it functions perfectly in other respects and would be an ideal candidate for what you're trying to do, I would have thought. Just pay P&P.

Cheers,

Nick.
Nickthedentist is offline  
Old 30th Mar 2018, 12:29 pm   #8
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Re: Is it possible to get more receiver volume from BT Statesman and Viscount phones

Thanks for your kind offer Nick but I'll pass. The Statesman and Viscount were almost scrap when I bought them so there's no need to worry ! I'll persevere.
Sparks is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 7:14 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.