Marconi F3049-02 : Joystick Controller

That MoD identification label is an awfully familiar style. Although NATO stock numbers were officially universal from mid to late 1970's in practice much of the kit I saw at RARDE up until the mid 1980's when I stopped having regular contact with direct from the military equipment made do with a simple MoD plate of that style.

Field and deployable equipment always got the NATO number. But fixed base, experimental and modified equipment frequently did not. Seemed to me that you could only be certain of finding NATO numbers on general issue equipment. Experimental and research et al kit, which was what I mostly dealt with, supplied via MoD made do with that sort of plate.

Clive.

Yes a very familiar format but for those less familiar, not to confuse MOD with MoD. MODification Record vs Ministry of Defence

Pete

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Not off the mark at all

The unit I have is built to very high standards, but it appears to be a commercial item ... it is not ruggedised for field use, and has no NSN [that was the first thing I looked for].

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As I have already stated, I don't wish to start dismantling it ... I did lift the lid, just far enough to see that all the leads to the D connector are pink, and have tiny heat-shrink identifiers. The back of a glass-fibre circuit board is visible, and the leads pass through clearance holes in the board. .... Any further investigation from that side would almost certainly involve damaging the original assembly detail [which I want to preserve].

I am, for the moment, treating this unit as a rare historic artefact.

If no information is forthcoming, I may try dismantling via the top plate; but that again seems likely to ruin the integrity of the original construction.

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Thanks to you, and Bazyle, for your thoughts

MichaelG.

A bit of lateral investigation. The F1158-02 circulator is still available from E2V https://www.cornestech.co.jp/tech/wp-content/uploads/sites/2/2017/02/e2v_microwave_product_guide.pdf (page 6) Teledyne E2V are based in Chelmsord and sprung from the break up of GEC Marconi. https://en.wikipedia.org/wiki/E2V

The F1158-02 in the catalogue has the same spec as the item on the link Michael provided in his first post. 'F' means ferrite, not Frimley.

Not a lot to do with the joystick but a clue maybe to ask E2V?

Pete

Michael

What you describe is very much military style construction, the description of the pink wiring gives me a flashback to some avionics systems I have worked on in that era.

I understand your reluctance to pull it apart. After testing with a meter your curiosity may get the better of you. Unlike consumer products the cost of manufacture made it a necessity to design them to be maintained. There will be a way of investigating its internals without compromising it too much.

Pete

Edited By Doubletop on 24/08/2018 08:34:24

The pink PTFE or ETFE wire was standard. Coloured wires not allowed because someone using it might be colour blind and get it wrong.

An interesting catalogue with way more products in the multioctave ECM TWT range than when I was getting parts from them. It also mentions the Lincoln site is still actively designing the ferrite devices which was where the semiconductor parts were also designed. If the part had an F number it might have come from Lincoln even though not involving ferrites.
Actually it was my job application to EEV at Chelmsford that stared my career in electronics though the job I got was elsewhere as they operated a group recruitment system.

As a bit of an aside; up to the late 60’s all avionics cabling was colour coded.

I was an RAF avionics apprentice in the mid 60’s, one of the guys in our entry had managed to get through the entry tests despite being colour blind. When we were doing training on systems he’d ask us to help him identify anything with colours cables, resistors etc. We thought nothing of it and would help him out. This went on for three years and at the end, as he was one of the brightest guys, he got selected for a commission as an engineering officer. He went for medical and they then discovered that he was colour blind. Rock and a hard place for the RAF, one of their top guys and they couldn’t use him. He got packed off to uni at their expense and then civvy street.

Pete

The pink colour convention is connected to the Modification Number. If during service an equipment was changed by design or repair, a different colour wire was used to make it easy for the next guy to see what was altered. Anything not pink is a change, and the absence of a colour means a modification hasn't been done.

Made a lot of sense when electronic equipment required constant maintenance and kit was upgraded through life, perhaps several times. During the 1970's the switch to printed circuits and replaceable modules reduced the value of wire colours : it was cheaper and safer to swap modules to match serial numbers rather than have blokes poke at it with a soldering iron.

More likely to find pink wires in military equipment because commerce often preferred to colour code wires by function - makes it a lot easier to trace wires, and understand what's what. It's not the law - I've seen pink wiring in commercial equipment and mixed colours in military.

Michael's joystick is probably a rare item, perhaps sold briefly and in limited numbers as part of a larger outfit, like a radar console. Identifying the main unit might be more fruitful

Dave

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Thanks for the info about pink wires, Dave ... I didn't know that.

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If you look back at my earlier notes, you will find references to 'marconiradarhistory'

Regarding identification of the 'larger unit' ... Here is, I believe, the most relevant page: **LINK**

http://marconiradarhistory.pbworks.com/w/page/54058331/Display%20and%20Data%20Handling

MichaelG.

For info.

For Scale: The top plate is 4.25" diameter, and the box is a 3" square extrusion.

The stick has large angular travel, so [for Pete] it's unlikely to be strain-gauge based.

No idea what the rubber bungs are for; there's a matching set on the opposite face.

MichaelG.

Interesting. I don't recall the particular add-on, but you can't remember everything. Connected via the user port, so digital, not analogue.

To get back to the original question, which pins are wired? That may offer somebody a clue.

Most people of my era first came across a trackball on the 'Missile Command' arcade game. Unlike a computer mouse, you can perch a trackball on top of whatever junk is on your desk and it still works perfectly

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All nine pins, plus a separate connection to an earth tag

... all in pink wire, with tiny Hellermann sleeves over the solder joints.

A proper job, but a tricky guessing game !

MichaelG.

Edited By Michael Gilligan on 24/08/2018 22:00:32

Not relevant to Michaels question really, but I think the 'user port' on the BBC micro had analogue and digital inputs.

Ian P

Nope. User port is digital. There is a separate analogue port. I still have one, with the documentation.

The fact that all 9 pins are wired does not really help identify the method it uses to communicate, other than to say that the most, maybe all, of RS232 equipment I have seen never had 'all' pins connected. Its unlikely that a joystick would need all RS232 lines anyway.

Whether this product was industrial or just commercial, it was made to aerospace type of standards and as such was surely designed to be serviceable or MOD-ifiable. I would suggest that it should be possible to access its innards without doing and damage and it would be the best way of finding out how it works.

Ian P

Oops! my error.

I still have a model B but no longer have the analogue joystick I made for it which I now realise did not connect to the user port (I had a RTC on that).

Ian

Far too robust and agricultural for an avionics system. Civilian, ground or naval radar maybe? An interesting read here. **LINK**

and maybe try theses guys

**LINK**

Dave's thoery of the reason for pink cables was interesting. On all the system mods I installed I can't remember ever using different coloured wires to define the mod. There would have been too many other things that could be replaced that couldn't be defined by the colour. If you wanted to know about a mod you checked the mod record plate and obtained a copy of the mod instruction and read it.

The discussion about BBC, Atari type computers is also incorrect. The only similarity would be the use of a 9pin D connector. This is clearly a milspec item and the design process would have started well before 1977 so pre-dates home computers by many years. If you are really lucky it could be one of the protocols around at the time, but I'd suggest unlikely. The good news will be that once you find out what it is one of todays  micro controllers could be pressed into converting the protocol to whatever you want it to be.

Pete

Edited By Doubletop on 24/08/2018 23:20:00

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Thanks for your continuing interest, Pete ... but that ^^^ is where we came in.

MichaelG.

Yes I thought I recognised it but yesterday I found a page on that website that went through the chronology of Marconi radar systems. Find one that is around the right period and you may be on to something. Then maybe go to the Bawdsey mob and ask them. Or just send them an email with your photos and see if they recognise it.

Pete