Tony Grant raised the question as to whether a “double-ender “was a cord with two PO jacks at each end for use on a jack field (or just any cable with two male plugs). A reversing double-ender had the tip of one plug connected to the ring of the other – and was often associated with a yellow cable.
John Howell
The term “Double ender” is solely for the ‘cord’ or studio cable (as in ‘Long Double Ender’) with a jack plug on each end. Strictly speaking the hole in the jackfield is the ‘jack’ and the thing you put in it is the ‘jack plug’.
The jack-knife apparatus got it’s name from the fact that connections are made by means of plugs resembling the handle of a "jack-knife" (from a book with the wonderful title "Electricity in the Service of man" published in 1897).
Mike Jordan
Strictly speaking, the plugs were PO316 and this had a smaller end tip and ring. Nowadays everyone in sound (outside the BBC?) use 1/4” jacks which are very different.
The departing Duty manager at BH proudly showed me his yellow (reversing) double ender which was almost the last proper cord remaining in the place! –
I had to add one of these 1/4” sockets to my “connect anything” kit that I still have use for doing odd sound bits locally.
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Barry Bonner
We had a very useful long reverse phase double ender in TC5 which we left plugged to the bay PPM, being yellow it was quick to find amongst the “Grandstand” spaghetti! Modelled here by H.Tel. Sound’s secretary.
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Tony Crake
We had lots of phase reverse cords in the CMCCR ( no switches on the Desk!).
Jeff Booth
In VT, a ‘double ender’ name was used for a cable with PO jacks.
Video cables were usually referred to by the type of plug on the end with phrases like ‘BNC to MUSA’, ‘BNC to BNC’ (MUSA – Multiple Unit Steerable Antenna (the MUSA apparently started life in the Radar business).
John Howell, Dave Plowman, David Denness
‘Our’ jack plugs are different in diameter than the ones on a guitar lead or domestic headphones. A genuine 316 sleeve diameter measures at 0.253" – Domestic stereo diameter is 0.247". You certainly cannot put a domestic jack into some of the all-plastic eg Rendar) 316 sockets. If you did manage to put a domestic jack into a 316 jackfield, with great difficulty, you would have damaged that socket for future usage – and that goes back many decades. Of course it’s the ring, tip and sleeve dimensions which differ.
Dave Buckley
From what I remember from the two excellent publications – Telephony volumes 1 and 2 – the reason the plug was ‘tapered’ was to avoid shorting the contacts when it was inserted into the socket on a manual switchboard as there was 50 volts all over the place.
For example, when you asked for a number on a manual board, the operator would touch the tip of the plug on a connecting cord the sleeve of the socket of the required number. If the operator heard a click in their headset, then the number was engaged. If it was an exchange to exchange call, and the first line in a run of circuits gave the click, then the rest of the lines in that run were also engaged.
Mike Jordan, Ian Hillson, Dave Plowman
I had to change the Rendar plastic one on my "Made in BBC BH Sound Test Room" in an Eddystone box oscillator to use with modern jacks!
Like the confusion over 2.5mm and 3.5mm jacks – mono/stereo/4pole on phones, and the dozens of different size/voltage of those nasty co-axial power connectors used on things, and all sorts of different USB etc connectors.
And now HDMI with network/digital audio extra pins.
Bring back 3pin D&S ( Dorman & Smith) so the fuses can vibrate out in the socket and give you a shock as in TC – superseded of course by 13A plugs with rotated pins.
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When the domestic 13 amp final circuit ring was introduced just after WW2 there were several different styles of plug. The present one only became the standard many years later.
D&S was one of them – much favoured by some councils in their estates – probably because it was cheaper than the MK one.
The BBC used the D&S plug to prevent something like a Hoover etc being used on tech supplies.
TfL still use metal 15A Niphans on their sign boards in stations so there is some history left working!
Tony Crake
The D & S plug/socket nasties were eventually replaced by Walsall Gauge 13A plugs: all the pins were at 90 degrees to a standard domestic 13A plug.
John Howell, Alasdair Lawrance
The mains leads were 4 pin made by Cannon. The Cannon EP4-14 was the chassis mounted male version, and EP4-12 was the female version on the end of the mains lead. The last number indicated the number of pins. And it was possible to put a low number of pins into a higher number socket.
Philip Tyler
Anyone remember the ‘mains’ XLR plug with the semi exposed pins? They did eventually get banned, although there was still the odd device using them back in 2009.
Pat Heigham, Ian Hillson
What was the unusual 3-pin mains plug that had a keyway on the earth pin – used for connecting to the smoothed, stabilised tech supply in the TVC galleries?
And what about the connectors on that nasty audio bay in LG studio R that carried ins and outs on the same connector, making flexible interconnections between the tape machines well nigh impossible compared to the ease of a standard jackfield as per the Apparatus rooms of TVC. These were the XLR LNE connector – but which is the plug and which is the socket!
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When Patrick switched to film, he came across Westrex dubbing bays which had the tip of the jackplugs wired as earth – on the basis that a loose swinging double-ender would not accidentally short out the signal if it touched the chassis of the bay.
Tony Grant
F&E connectors (I had always understood them to be ‘Film & Equipment’) were the ends of monitor video leads, with a screw thread to secure them to their socket on the wall box, unlike BNC which were bayonet style connections.
Dave Plowman
F&E made a variety of connectors for different applications. There is a tendency to call a connector used in a specific application by an easy to remember name. So ‘cameras’ may use F&E to mean a different connector to ‘sound’. But at one time both the video and mains connectors used on a monitor were both made by F&E. Luckily, safer mains connectors than the F&E have been used for many a year now.
Alex Thomas
Vulnerable cables were used at Aintree on the Grand National course. The cameras at Becher’s Brook and Canal Turn were cabled with red Triax. The small public enclosure at the Canal Turn attracted the crème de la crème of "Hooray Henrys" who took a delight in pulling apart the joints in the camera cable. We would park our cars over the joints and keep the cable tight around the joints so that the cable could not be dragged out and disconnected.
I was at a by-election in Newcastle with the late Vincent Hanna. We were knocked off the air when a tired and emotional Geordie wandering about the underground lorry park beneath the site of the declaration pulled the green cable feeding the Comms dish out of the Comms truck. He then urinated into the dead end of the cable. I’m not sure what surprise the live end would have given him and the voltage he fortunately avoided.
Dave Buckley
With regard to BNC video connectors, just to confuse the issue, there were two versions – 50 ohm and 75 ohm. From what I remember, the centre pins were slightly different.
Tony Crake
You have to be a Comms Man or a Radio Ham to get any sort of a grip on coaxial cables and their connectors.
It is very difficult to say if a BNC is a 75 ohm or 50 ohm one. Sometimes if the serial number on it has 50 in it, it’s 50 ohms… or if has a 70 in it, it may be 75… It all depends exactly what cable of the hundreds available it was designed to fit.
Alec Bray
In the early days of Networking in the IT industry, we had immense fun(?) sorting the 50 ohm and 75 ohm coax cables. 10BASE2 Ethernet (aka thin-wire Ethernet) used 50 ohm cable and 50 ohm terminators: the cables had to be terminated otherwise the signal reflected back down the cable (Carrier Sense Multiple Access With Collision Detection (CSMA/CD) – if the carrier is detected, no station trnsmits). Some equipment included their own terminators, so that these items had to be placed at the end of the cable run. In those days, there was a single run of Ethernet cable, each piece of equipment was connected to the cable using a Tee-piece connector. Of course, we also had video equipment which used 75 ohm coax. Now, if you connected a 75 ohm cable into the thin-wire Ethernet … you would spend ages trying to figure out why things didn’t work. Also, the desk chairs could run their wheels over the coax (as it was simply strung along the floor) with the result that the cable could collapse…. you would spend ages trying to figure out why things didn’t work. Only one end terminator could be earthed (earth?) otherwise you could get grounding loop problems … you would spend ages trying to figure out why things didn’t work.
Pat Heigham
Having worked with video facilities company, all the video cables feeding our monitors were 75ohm and my radio mic aerial cables were 50ohm. The centre pins were of slightly different diameters – and it may have been the solder bucket that differed depending on the RG cable in use for each application.
I went behind the Berlin wall some while back to film a doco about the ice skater Katarina Witt – she addressed the East German parliament about some issue and we filmed that. Needed a feed of the PA system from the lectern. Their in-house engineer showed me an audio distribution panel in the audience area, but they were Tuchels! He asked did I want Tuchel to XLR adaptor for my mixer i/p. Yes, please. And I’ll send you zero level tone, he said. Wound the pot round to the usual setting for a line input, and tone was exactly at PPM4.
Mike Jordan, Ian Dow
Basically 75ohm BNC (Bayonet Neill-Concelman) was for video and 50ohm (larger core) for RF and aerials etc. There were also TNC (Threaded Neil-Concelman) which was a twist lock version.
Being a bit of an oldie in OBs, we also had F&E, N types, C types (bayonet), Telcons, screwed C for RF as well. Now of course there are nasty UHF connectors for TV aerials and F connectors for satellite. MUSAs for jackfields and Burndepts – the name of the one on the end of BT coax cables – have to be added.
Back to the EP series – the 4 pole were for mains and various others were audio ranging from 3 pole for loudspeakers and even more for microphones to include various control/power supply connections. EP5 was used on SOOBE kits (Self Operated Outside Broadcast Equipment) to carry the audio and control connections to a pair of BT lines at places like football grounds and later changed to EP6 for COOBE kits (Commentator Operated Outside Broadcast Equipment). I have one of those test leads in my garage (of course!).
EP4s along with Niphans were condemned as there was no hard connected contact between the metal shell and the earth pin – hence
move to XLRs and then Powercons.
Chris Woolf, Bernie Newnham, Dave Plowman
Tuchel (Klein and Groß) was the old German standard broadcast connector.
Tuchel was a German company that made several different connectors before being taken over by Amphenol.
Many of the connectors were the European-style DIN connectors beloved of 60s and 70s Hi-Fi. They also made a rather clever jackfield that could plug both go and return using a single cork. That meant that outboard gear could be plugged with far less knitting. The jack plugs had a circular core with 5 radial blades, and serrations that provide a spring locate to prevent them falling out.
John Howell (Hibou)
We had Tuchels on the EMI equipment in Lime Grove Studios D, E & G on the insert jackfields: they had large wiping contacts that made them very reliable. The insert points were unbalanced so any dirt on the earth leg could mean violent oscillation if the inserted device had any gain.
I learned later (at the Olympics in Moscow) that they were extremely versatile having 5 contacts in a ring at the front of the socket and 5 at the rear. You could elect when you inserted a plug that the front and rear rings were joined by a long metal blade on the plug making a ‘listen setup’ or, with an insulated break in the blade, making an ‘insert setup’.
Dickie Chamberlain pushed the EMI desk in Studio G to its limits on “Top of The Pops” and persuaded the powers that be that more insert facilities would be beneficial. I came in one morning to see an installation engineer cutting the holes for the new Tuchel sockets. He had a scaffold pole over the end of the Q-Max hole cutter and was using a lot of his weight to punch the hole. I had much respect for those Denco hole cutters after that!
Mike Jordan
Found my Tuchel to XLR/PO jack as used for connecting camera and sound, excluding headsets, to BBC Comm boxes! Complete with wiring instructions if needed.
EP4 and XLR s:
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Tuchel headset connector:
Tuchel Wiring:
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The COOBE lead was for boxes to BT lines testing
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Mike Giles
In Moscow we had to modify quite a number of Tuchel cords to loop a listen of the commentary because offering parallel feeds to VT via the standard Tuchel parallels extended the control line and feedback as well as the commentary circuit and apart from the aggravation of adding unwanted contributors to the venue circuits, the extra loading meant that the ringers weren’t always reliable, or that when they did work, Jim Reside in VT would bend our ears about his phone ringing every time the venue wanted to call Martin Hopkins or Jonathan Martin in the gallery. It was probably whilst making up one of these commentary listen Y-cords that John famously soldered his accreditation.
John Harris of PID as it was then, I think, cornered virtually the whole of the available supply of Tuchel plugs and sockets, so that we could make up the Y-cords, whilst overnight he added a long strip of Tuchels to Paul Mason’s desk on the plinth at the back so that he could get across the control lines to perform his TM duties in lining up with venues without having to lean over the production team ~ at least I think that was the problem.
I also recall the surreal experience of being alone in the BBC area one evening before the games started, whilst the rest of the studio team went to the Bolshoi. I was taking the opportunity of having no-one else around to lift up the computer flooring to run tie-lines into the studio as there were nowhere near enough provided. Surreal on two counts ~ firstly, I couldn’t believe that I was running cables under the floors in a broadcasting facility in Moscow, of all places, and even the leather-jacketed security man didn’t ask what I was up to; secondly, that having never lifted computer flooring before, I didn’t realise the importance of not lifting too many tiles in a row until I felt the floor swaying slightly and realised just in time that the legs supporting the floor were free-standing, so the front and back of part of the control room floor were in danger of sliding together like tectonic plates! I had to use some force to lever a first tile back into a slot in the middle of the channel I had created, but I don’t remember ever admitting at the time how close to disaster I thought I had been. Though I do remember discovering how sharp the edges of the aluminium floor tiles were.
John Howell
The strangest gaff we committed was not asking one more question, having had many encouraging answers about the facilities in the studio. "Were they wired up?"
What about the way that the Russian team froze when the Orange Phone rang!
Plugs
| Abbreviation | Definition | |
Sockets
| Abbreviation | Definition | |
| F&E | 3-pin – 1 inch diameter – Foldback | |
| F&E | 3-pin and 5-pin – 1 inch diameter – PA | |
| F&E | 4 pin – 1 inch diameter – Monitors | |
| F&E | 7-pin – 1 inch diameter – Boom |
Connectors
| Abbreviation | Definition | |
| BNC | Bayonet connector: – Bayonet Neill–Concelman | |
| Tuchel | (Klein and Groß) The old German standard broadcast connector | |
Bernie Newnham
All proprietary madness.
I don’t know if many here take an interest in new cameras these days. I’ve been involved in picking low cost gear since the 90s and the Sony VX1000. Sony and Panasonic – especially Sony – just love to come up with some new system for each new camera, Usually jolly expensive new systems (like Apple). Cameras at the £2000 – £5000 or so price point all used to use DV tapes, costing just a few pounds. At universities such as the one where I work, students were expected to buy their own stock, in the way they buy pencils etc.
When solid state recording came along, suddenly you couldn’t find in the spec list what they were recording on to – it was hidden far down in the list somewhere. Try it now – look up a mid range Sony camera and try to find out what it records on. Surprise surprise, it’ll be Sony’s special stuff and expensive. Even at this camera price, up to recently they wanted you to buy SxS cards, anything from £200 to £800. How to misjudge your market! Now they’ve moved on to a new type of card which is a bit cheaper but still out of student range. Meanwhile, over at JVC – by far the underdog – they sell cameras heavily labelled "records on SDHC". The right answer. Buy JVC folks, and your children and your childrens’ children will prosper and grow fruitful.
And finally …
Nigel Taylor
A plug for a website –
http://www.fam-oud.nl/~plugsocket/index.html
Watts it about? The title gives it away –
Digital Museum of Plugs and Sockets
This site has great potential for those of you who like current affairs. Don’t refuse to look. Wire you waiting? Flex those fingers and go to the site, you’ll be amply rewarded – though if you find it so interesting that you don’t want to leave ohm, it’s your own volt.
