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This page is intended to help people who are seeking or offering assistance with matters relating to BBC engineering. To contact the originator of an item below, click the link in the relevant section.  I will forward your email to the intended recipient. Let me know if you would like an entry on the page.

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13 Current items                         Click for: 43 Resolved items and 63 Expired items

2 Nov 2018 Harry Rantzen Tony Taylor writes: "I am a retired academic historian living in Australia and I am currently working on a project which takes in the social, political, economic and military histories of the four families that came together when my wife (Scilla) and I married in 1968. One of those families was the Rantzens.  Harry Rantzen was my father-in-law. I knew him very well and I was very fond of him. He was courteous a man of formidable intellect right to the end of his days (he died in 1992, aged 90).

I have reached the section in my story where Harry is Head of Design[s Department] during the post-war period and while I have found two useful comments about his managerial style (his nickname was 'Tiger'apparently), there is a period (1950-1952) when he went to New York to supervise the setting up of UN's global telecommunications network. There is some dispute about how this was arranged. Harry maintained that he was seconded by the BBC but when he returned in 1952 he was told there was no job for him. The staff who have written about this incident refer to 'secondment' but his Designs staff farewell photograph (March 1950) refers to 'resignation'. Harry believed that his boss Harold Bishop, with whom he did not get on apparently, edged him out and left him high and dry on his return from the US."

26 Oct 2018 Continental Microwave Links

 

 

 

 

 

Resolved

Gwil Jones writes: "I have acquired a Continental microwave audio and video link transmitter both originating from BBC Kendal Ave. As far as I know they were one of the main link transmitter used from the mid 1980’s. This particular unit was last tested by SIS in 2011.

I have seen a few photographs of these units on your external members links and of course the operation of the unit is self explanatory, but there is a list of codes for a small display which will say “check” and then a number could be 1 or 4 and I am wondering if there is anyone who can shed some light onto what these numbers mean. I have had a search around and being bespoke to a small number of broadcasters I haven’t been able to find any information. Continental microwave has now long gone, and any information would be gratefully received."

Reply from John Levett:
"Re your enquiry, I dealt with this kit from time to time. The 4 position switches set the operating frequency. Positions 1, 2 & 3 could be pre-programmed, and were probably arranged as their standard 7GHz channels A, B & C 7125, 7160 & 7312.5MHz. On position 4 the frequency was selected on the thumb wheel switches. I notice it is still set to their Channel D, 7347MHz. The output power was around 1.5 watts on a good day. I think the readout on the control unit was confirmation that the channel in use on the head unit coincided with that selected on the control unit. There was some telemetry on RF carriers both ways along the triaxial cable - I forget what frequencies were involved.

The FM modulator at the first IF of 70MHz is in the control unit and that signal is sent along the triax - in addition to the DC powering the head unit. In the head unit it is mixed with a local oscillator at 730MHz to produce a second IF at 800MHz, before being mixed with the SHF local oscillator up to the output frequency. If you have a 70MHz FM demodulator you would be able to see video - but it may not look very good as it will be pre-emphasised - and covered in the sound subcarriers (6.8 & 7.5MHz) if they are switched on.   Hope that helps."

 

14 August 2018 ME2/4/A/101 ‘Sweep Form 2’ option' Russell W. Barnes (STE Skelton) writes: "I’m looking for a cct-diagram and any info for the a.c. test-set type ME2/4/A/101 – more specifically, the version with the ‘Sweep Form 2’ option. Our ‘heritage’ ACO books at Skelton don’t cover this kit, and I can’t see it on the comprehensive ‘enginfo’ list either. Any information we once had on the unit has now gone astray.

It looks like the Sweep Form 2 version uses four EEPROMS on a discrete PCB at the back of the instrument, but, without a circuit it would be big job of comparing and contrasting with our last known worker. The test-set works fine but the sweep waveform generator has failed, and I’m afraid it isn’t simply a case of a dirty switch. All assistance gratefully appreciated!

3 August 2018 Fatality at BP Kate Terkanian writes: "I am working on a PhD on the BBC and was wondering if anyone has any information on a fatal accident that occurred at Brookmans Park, probably on 12 March 1941? I have found a reference to it in BBC files, but the archivists can’t find any further information on the accident. The records say R.W. Angell was killed, but further research leads me to believe it was Ronald Walter Angell. He would have been 39 at the time. Probate records list his death as 12 March 1941 at the Hospital in Barnet. Any information would be helpful."
2 May 2018 Master Clock Drive Unit
CA1/6A
Mike Davis and Bart Schipper are (separately) seeking information on master clock drive unit CA1/6A such as circuit diagrams, service handbook or operating handbook. It was probably used mainly in local radio stations.

The boards within the unit are marked with the following code numbers:
AM24/1 (amplifier PCB), OS2/41 (oscillator PCB), UN1/160 (frequency divider PCB).

28 June 2017 Switch to Colour TV Phil Loweth writes: "I am a researcher for The One Show. I am looking into the possibility of making a film to mark the 50th Anniversary of the first UK colour TV transmission, which is this Saturday [1st July 2017], and was hoping that you may be able to help me.

We are looking for people who were around/involved at the BBC when this happened, either cameramen or engineering ops, who can describe how the change felt for them. Whether they felt a huge sense of achievement, if they feared that everything might go wrong or if they were just overwhelmed by the new equipment (if the equipment was hugely different). Is this something that you would be to help me with? I look forward to hearing from you."

1 June 2017 CT80 jingle machine

 

Resolved

Graham Vine writes: "I bought the "cold war bunker CT80s" and they are of course in a rather sad state. It would be nice to renovate one or all the 4 machines but I don't wish to do damage in stripping them so I wondered if anyone had maintenance/repair information on them. They are all recorders and mostly complete - certainly enough parts for 3 out of the 4. I could probably create the missing PCBs if the rest of each machine was functional.  It would be nice to create an original Radio 1 studio."

  Resolved - Information provided by Jim Harpur.

28 May 2017 Our World James Hayes, a freelance journalist, is researching an article about aspects of the enabling technology involved in the pioneering ‘Our World’ TV programme of 25th June 1967. He’d be interested to hear from people who worked on the technical side (TV and satellite) of that broadcast, or who know about it. If you think you might be able to help, please email before Friday 2nd June 2017.
11 Mar 2017 OBA8 connector Yorkshire Air Museum is trying to find a plug for the equipment shown below.  Can you suggest where such an item could be purchased? The pictures below show the connector and the equipment it is used in. The request came to bbceng via Dave Porter.

28 Feb 2017 CH1/18E Lee Mouatt writes: "I'm looking for any mechanical drawings of the CH1/18E type metal chassis, used for various BBC rack modules such as the PS2/49..... I have a few BBC studio racks fitted with some modules, but I have a fair few empty spaces in them. I was hoping to fashion a few of the CH1/18E style chassis for retrofitting other audio gear into the BBC racks. Cheers, Lee".
3 Dec 2016 Bing Tone Generator

Keith Wicks writes: I'm looking for information on bing tone. I remember we used to use this slowly pulsating signal before startup of the main radio networks in the early 1960s. I think it was described as the least disturbing signal to have to listen to for long periods.

Does anyone know what the frequency and waveshape were, and are there any publications on the subject? I ask because I occasionally have the need for something similar and thought I'd build a generator. I'm hoping to find a circuit of a transistorised Bing Tone Generator, if such a thing was ever made, but a valve circuit would be of interest too.

Any help would be much appreciated.

16 Nov 2016 "Digger" Dimmock

Gavin Dimmock writes: I found your web page and email while searching online for information about my late grand father, James William Dimmock.

He was employed by the BBC between July 1946 and May 1972 when he retired. I believe he worked in S.P.&.I.D. and, for a time at Bentinck House. I have very little information about his working life and am keen, if possible, to discover more.

I believe he was possibly a draughtsman. His nickname (I do not know why) was Digger.

If you are able to provide me with any suggestions of how to proceed, or where to go next, I would be so very grateful.

13 Oct 2016 Alexandra Palace - colour date?

John Escolme, BBC History Manager, writes: "I am trying to find out when Alexandra Palace was equipped for 625 line colour production.  Did they get it done in time for the Wimbledon colour launch 1st July 1967, News and Sport from AP was at 1930 that day.  I suspect it was not ready, as only a select number of programmes went out that day in colour officially, and all from, or via TVC.

Wimbledon, all week +Match of the Day
One Pair of Eyes, Sat July 1st
The Virginian, Mon July 3rd
Impact, Thurs 6th July
Late Night Line Up all week

This info comes from the RT at the time, so I dont preclude colour coming from AP early, but it might be that AP was not ready for 625 line colour at all until News started in colour on BBC1 in 1969, which of course then was still coming from AP. I do realise there were colour tests from 1954, but thats another matter.

Any ideas?   Thanks   John" 

     
     
     
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