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 7th Mar 2019, 7:53 pm   #1
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Radio 1 Roadshow, 1970s and 1980s

Does anyone know the means by which the BBC conveyed broadcast sound from the Roadshow site to Broadcasting House in London ? I assume the GPO/British Telecom were involved somewhere, somehow. Would it have been wire or microwave links to a telephone exchange or relay tower ?

Thankyou.
Sparks is offline  
Old 7th Mar 2019, 10:40 pm   #2
Guest
Guest
 
Posts: n/a
Default Re: Radio 1 Roadshow, 1970s and 1980s

At school in the 70's we had the road show, went by telephone lines (two pairs to get the bandwidth) I was much more interested in the OB van than the show. I vividly remember thin twisted pairs being attached to large screw terminals. I was in East Anglia at the time where Radio 1 (MW only) reception was awful.
 
Old 7th Mar 2019, 11:19 pm   #3
peter_sol
Octode
 
Join Date: Aug 2003
Location: Welwyn Garden City, Herts. UK.
Posts: 1,906
Default Re: Radio 1 Roadshow, 1970s and 1980s

PO lines before stereo. but at first had satelite link from BT when needed stereo.
I don't think there were 2 pairs used on the one circuit, It would have been 1 pair for programme line and one pair for control line (talkback)
peter_sol is offline  
Old 7th Mar 2019, 11:34 pm   #4
peter_sol
Octode
 
Join Date: Aug 2003
Location: Welwyn Garden City, Herts. UK.
Posts: 1,906
Default Re: Radio 1 Roadshow, 1970s and 1980s

https://drive.google.com/file/d/1Tx3...M5vV2beX9/view

Interesting article here.
peter_sol is offline  
Old 7th Mar 2019, 11:38 pm   #5
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Re: Radio 1 Roadshow, 1970s and 1980s

Thankyou Merlin and Peter. How would use of telephone lines work in practice ? For a regular subscriber to access the telephone network means plugging an approved instrument into a wall socket which is in turn connected to a telegraph pole or something similar. How would a broadcast mixer interface with a telephone line ?
Sparks is offline  
Old 8th Mar 2019, 7:29 am   #6
peter_sol
Octode
 
Join Date: Aug 2003
Location: Welwyn Garden City, Herts. UK.
Posts: 1,906
Default Re: Radio 1 Roadshow, 1970s and 1980s

The broadcasters used "Music lines" when avaliable which were equalized for frequency at the receiving end.
They were connected at both ends with balancing transtormers and fed from an impedance of 75 ohms in the case of an OB or 600 ohms in the case of a shorter fixed line.
Terminated with 600 ohms at the receiving end.
The lines for the OB's were set up by BT so would be just the cable ends coiled up out of sight somewhere near or a terminating box if used frequently.
The mixer would be connected to a dedicated box which had the line sending and receiving amplifiers all in one unit for the programme line out and the control line (talkback) in.
peter_sol is offline  
Old 8th Mar 2019, 8:28 am   #7
Electronpusher0
Nonode
 
Join Date: Jun 2016
Location: Bognor Regis, West Sussex, UK.
Posts: 2,288
Default Re: Radio 1 Roadshow, 1970s and 1980s

I remember attending a Radio 1 roadshow at Portsmouth when I was at the Polytechnic (now a "University", don't get me started).
The only thing I remember is how boring it all was despite the presenter trying to whip up enthusiasm.
Peter
Electronpusher0 is offline  
Old 8th Mar 2019, 10:08 am   #8
McMurdo
Dekatron
 
McMurdo's Avatar
 
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,263
Default Re: Radio 1 Roadshow, 1970s and 1980s

That was a nice read, loved the bit where the engineer said they had sometimes used the output of a PA amplifier to drive the BT lines in remote places so the audio arrived in London intact!
__________________
Kevin
McMurdo is offline  
Old 8th Mar 2019, 10:27 am   #9
unixmanuk
Pentode
 
Join Date: Jan 2012
Location: Worcester, Worcs. UK.
Posts: 112
Default Re: Radio 1 Roadshow, 1970s and 1980s

I was a TA on BBC OB Comms in the early 80's. I used to have to go out on sound lines testing, and test equalization and frequency response on the pairs before the big day. I'd leave a little card with the the equalizer settings, so that the box could then be attached and quickly set with the correct settings.

With the Radio 1 Roadshows, we used a mobile satellite uplink on a trailer IIRC, and off air programme monitoring from the nearest VHF broadcast station.

For TV OB's, we set up microwave (7GHz approx) links back to the nearest main TV transmitter, such as Crystal Palace in London, Wenvoe, Sutton Coldfield et. al. The main site would have have steerable antennae, so we would be on the end of a "left a bit, right a bit" type situation getting it set up right. Some of these links would be multiple hop as well.

happy days
__________________
John
unixmanuk is offline  
Old 8th Mar 2019, 10:41 am   #10
Sparks
Heptode
 
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 593
Default Re: Radio 1 Roadshow, 1970s and 1980s

Thankyou for such detailed replies everyone. I knew there had to be more than plugging a mixer into a telephone but I didn't appreciate the level of consideration.
Sparks is offline  
Old 10th Mar 2019, 9:41 pm   #11
Valvepower
Octode
 
Valvepower's Avatar
 
Join Date: Aug 2008
Location: Rayleigh near Southend-On-Sea, Essex, UK.
Posts: 1,852
Default Re: Radio 1 Roadshow, 1970s and 1980s

Hi,

This is a tad off topic, but I remember in the early 70’s the Radio One Roadshow using the Orange (as in the amplifier manufacturer) 200-Watt slave amplifiers. This was a great piece of valve engineering by the great Mat Mathias using 4x KT88’s with the GEC/Williamson/88-50 type driver circuit.

According to the Orange web site and folklore Emperor Rosko (Now - that’s a real DJ name!) used them in his Roadshow/Disco system and on his recommendation, they were adopted by the Radio One Roadshow.

Regards
Terry
Valvepower is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 9:24 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.