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 30th Sep 2020, 2:59 am   #1
The Operator
Diode
 
Join Date: Sep 2020
Location: Chesterfield, Derbyshire, UK.
Posts: 4
Default Fitting a BT Viscount MF circuit board into a Viscount pulse dialling phone

Hi. I recently bought a BT Viscount pulse dialling telephone in very nice condition and was considering replacing the circuit board with the MF circuit board from another Viscount.

Question is, would the MF circuit board from the more recent Viscount fit inside the body of the older Viscount and would the MF/LD pulse switches underneath prevent the circuit board from sitting properly inside the case of the older Viscount?

Thanks for your help.
The Operator is offline  
Old 30th Sep 2020, 8:49 am   #2
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,510
Default Re: Fitting a BT Viscount MF circuit board into a Viscount pulse dialling phone

Quote:
Originally Posted by The Operator View Post

Question is, would the MF circuit board from the more recent Viscount fit inside the body of the older Viscount and would the MF/LD pulse switches underneath prevent the circuit board from sitting properly inside the case of the older Viscount?
Hello, and welcome to the forum! The only Viscounts I have seen have the switches for LD or MF and TB, sat in a recess behind a clip-on plastic cover on the LHS as looking at the base of the telephone.

Has your model got this recess in the case and two holes where the switches go? If so, there's a chance the board will fit.
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline  
Old 2nd Oct 2020, 7:23 am   #3
The Operator
Diode
 
Join Date: Sep 2020
Location: Chesterfield, Derbyshire, UK.
Posts: 4
Default Re: Fitting a BT Viscount MF circuit board into a Viscount pulse dialling phone

Thank you. Yes, I can see 2 recesses. The underside of my Viscount 9521AR looks exactly the same as a photo of an MF version I've seen. Looking through the holes I can see the back of the brown circuit board, nothing else. Strange that BT would design the body to accommodate MF switches but then fit a Pulse only circuit board.

I can't see any screws underneath so it looks like the case needs to be unclipped to open it up.
The Operator is offline  
Old 2nd Oct 2020, 12:05 pm   #4
The Operator
Diode
 
Join Date: Sep 2020
Location: Chesterfield, Derbyshire, UK.
Posts: 4
Default Re: Fitting a BT Viscount MF circuit board into a Viscount pulse dialling phone

Just noticed the single screw underneath where the handset goes.

It seems to come off easiest if it's held upright and then gradually pulled away from the base from left to right, pushing the hook switch in as you move across.
The Operator is offline  
Old 2nd Oct 2020, 1:49 pm   #5
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,510
Default Re: Fitting a BT Viscount MF circuit board into a Viscount pulse dialling phone

What will you do about the * and # keys? Does your LD-only phone have holes for them with 'blank' (non-functioning) buttons in there?

You beat me to it about the screw beneath the handset rest. The telephones were made by ST&C and would be made with economy and versatility in mind. It's interesting to note that the 'InDEX' digital PABX telephone system used instruments with cases and handsets that were obviously based upon the Viscount, but not quite the same.
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline  
Old 2nd Oct 2020, 2:36 pm   #6
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,510
Default Re: Fitting a BT Viscount MF circuit board into a Viscount pulse dialling phone

Here's what I mean... Viscount MF / LD from 1980s against an InDEX DT3, late 1990s.
Attached Thumbnails
Click image for larger version

Name:	phones_01.jpg
Views:	65
Size:	100.0 KB
ID:	216858   Click image for larger version

Name:	phones_02.jpg
Views:	57
Size:	98.7 KB
ID:	216859  
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline  
Old 2nd Oct 2020, 4:27 pm   #7
Nickthedentist
Dekatron
 
Nickthedentist's Avatar
 
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 15,714
Default Re: Fitting a BT Viscount MF circuit board into a Viscount pulse dialling phone

I've seen those before and noticed the similarity.

But I have to say that the cleaner lines of the ~15 year older original get my vote. The InDEX looks cheap and fussy in comparison.
Nickthedentist is offline  
Old 2nd Oct 2020, 5:06 pm   #8
russell_w_b
Dekatron
 
russell_w_b's Avatar
 
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,510
Default Re: Fitting a BT Viscount MF circuit board into a Viscount pulse dialling phone

Quote:
Originally Posted by Nickthedentist View Post

But I have to say that the cleaner lines of the ~15 year older original get my vote. The InDEX looks cheap and fussy in comparison.
I agree, Nick. The InDEX system worked very well and the DT1 instruments (later provided by Avaya) were great. But the basic DT3 instruments, as shown, were prone to failure. Not due to the complexities of the circuitry within, but simple things like mic failure, switch failure and poor cordage.

I had a Viscount for years (not the one shown) and ultimately it suffered from keypad intermittency, but this was rectified by cleaning. The weakest point was severe discolouration. A nice telephone all the same. I still have it so may try dunking the case in 'Oxy Action' in sunlight (a cheap 'Retrobright' process).
__________________
Regds,

Russell W. B.
G4YLI.
russell_w_b is offline  
Old 2nd Oct 2020, 8:54 pm   #9
Jim_746
Pentode
 
Jim_746's Avatar
 
Join Date: Jul 2010
Location: Leyland, Nr. Preston, Lancashire, UK.
Posts: 181
Default Re: Fitting a BT Viscount MF circuit board into a Viscount pulse dialling phone

Are you sure that your Viscount is a 9521R or 9525AR? Telephones UK lists them as LD/TD switchable models.

I wonder if the board has been replaced with an LD board at some point in the past.
__________________
"And what on earth are you going to do with that?"
Jim_746 is offline  
Old 3rd Oct 2020, 6:44 am   #10
The Operator
Diode
 
Join Date: Sep 2020
Location: Chesterfield, Derbyshire, UK.
Posts: 4
Default

Quote:
Originally Posted by russell_w_b View Post
What will you do about the * and # keys? Does your LD-only phone have holes for them with 'blank' (non-functioning) buttons in there?
The 9521AR has the same number of buttons as the MF version though * and # are replace with buttons that have . and .. on them.

Quote:
Originally Posted by russell_w_b View Post
Quote:
Originally Posted by Nickthedentist View Post
I had a Viscount for years (not the one shown) and ultimately it suffered from keypad intermittency, but this was rectified by cleaning.
This is the thing I was worried about. The phone I have is new/old stock so I was originally reluctant to fit an old circuit board into it just in case the keypad membrane proved un-reliable.

Quote:
Originally Posted by Jim_746 View Post
Are you sure that your Viscount is a 9521R or 9525AR? Telephones UK lists them as LD/TD switchable models.

I wonder if the board has been replaced with an LD board at some point in the past.
I was hoping the website was correct though the manual confirms that it is LD/Pulse only.
The Operator is offline  
Closed Thread

Thread Tools



All times are GMT. The time now is 9:12 am.


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 - 2021, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.