CTV [Sticky] 1977 Rank Arena AC6333 - T12A Chassis - Teletext

Hi Chris, here are the photos you asked for of my Bush Teletext remote, it should be pretty easy to build an electrical replica especially if you have the circuit diagram, the only problem you may encounter is the tuned circuit used to step up the voltage drive to the ultrasonic sender. If you need the inductance to wind a coil let me know, and I can measure mine, sorry about the delay but time is short at work, I need to deliver 110 water units for next Wednesday. 

@michael-dranfield Thanks Michael, that's very much appreciated. I think looking at the rank teletext book, I do have the circuit, now with the measurements you've provided, it might be doable. I just need to somehow tie up with @jayceebee when he has some free time, to flesh this idea to see if he might be able to replicate the remote PCBs in Kicad for me. 

If it is possible to build one, then I need to find someone who could 3D-Print the remote case for me.

The things we do for tellies!

Should be dead easy to replicate the electronic bit, not sure about the case I don't do 3 D printing, The bit you might struggle with is the auto transformer so I have measured the inductance from mine fir both the primary and secondary, the pot core appears to be a Mullard FX2502 which I have in stock but you would have to get the datasheet

to calculate the turns ratio. 

Posted by: @crustytv

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I need to find someone who could 3D-Print the remote case for me.

Well, it looks like it won't be Shapeways any more... I didn't know they were part of Philips at one time?

Just to be clear, it was the American parent-company of Shapeways which went bust. Shapeways itself is starting up again as an independent business in Eindhoven. I'd link to the article but it's behind a paywall (and also in Dutch). 🙂 

Where I work we use this place for prototypes. Fast, cheap AND good!

https://jlc3dp.com/?from=VG3DP&gad_source=1

Very easy to just upload your files, the job gets costed on line, pay by credit card.

Next week your PCBs or 3D printed mechanical bits arrive as if by magic!

The quality is exceptional.

Chris, I managed to locate the ultrasonic teletext remote for this set. It has suffered from poor storage but I hope you will manage to bring it back to life. I will send the handset to you in the next few days. See my post regarding Ferguson 3V54 service manual.

😲

OMG ! My flabbergast is off the flabbergast scale!

I'm stunned Oliver, that has totally made my day, and I'm so grateful, this is such great news.

Please let me pay postage and cover all costs. I will pm you.

Chris,

 I thought I had sent pictures of the remote. I will try to upload again.

Regards,

 Oliver.

Wow! Oliver, I'm even more gobsmacked!

I hadn't realised the remote you've kindly offered is the "actual" remote for the prototype TV I have. Clearly badged as Rank Arena, the same as my TV, you can also see the subtle differences on the remote compared to the production release Bush version Michael has. Not just the naming but lack of LED indicator and the controls not split in two halves.

Press text then page before putting page number in.

Posted by: @rbmt20a

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Chris, I managed to locate the ultrasonic teletext remote for this set. It has suffered from poor storage but I hope you will manage to bring it back to life.

Hi Oliver, as mentioned in the pm, the remote received safe and sound. 👍 I thought I'd share the dismantling in the project thread.

I didn't quite understand what you meant when describing it as "having suffered from poor storage", based on the photo above, I do now.

This will be a challenge, but one I'm certainly up for, I recall working on my first Thorn 9000 a Multibroadcast badged 773. That had been stored in a metal shed and had sweated away for years. Nearly all the silicon had suffered, as you can see from the link, especially the IC's, but I eventually got that working and it gives a wonderful picture.

The IC may need changing, I will have to see, I don't have any in stock and a quick look online reveals they pretty scarce. The tracks are badly corroded, but I believe they can be repaired, but I'm not sure how conductive the board as become. L1 looks OK, but we'll have to see. My initial concern is the transducer, I know nothing of these devices, it's heavily corroded, and I've no idea if this will impact its operation, my gut is saying that is component looks toast!

Can you fit any transducer, or are they specific for the cct?

Chris, I am not sure if circuit specific. May I suggest you open up the other basic  remote I sent and see if it is the same type? Looking at the training manual, the transducer is referenced in the diagram as 11LS1. Do you have the service manual for the BC6378A or any other RBM model using the basic ultrasonic system and see if the circuit to drive the transducer is the same?

Regards,

Oliver,

The Z918 remote has a slightly fatter transducer, but it appears in perfect condition. Looking at how it is driven with my untrained eye, and allowing for some component value differences/omissions, it looks to be the same as the prototypes.

Chris, I think it would be a suitable replacement.

Regards,

Oliver.

I believe I've found the identical transducer in a Rediffusion ultrasonic remote that Malc gave me.

Also, should the ITT SAA1024 i.c in the Rank remote prove to be faulty due to corrosion, the chip in the rediffusion is in excellent shape. It's an M1024B5, looking at the datasheet it is an equivalent.

Now to set about carefully removing all the corrosion on the PCB and discover how the traces have faired. Thanks, Oliver, you've given me a fighting chance of getting the receiver's text working.

Main board released from ribbon cables, ready for clean, here are some pictures to document the process. Next ones will be after the PCB clean, and we shall then see what remains of traces. I'll also try to measure L1, as I fear for the winding.

Both sides of the board cleaned, the traces seem to be OK with just the mask having flaked. A lot of components solder joints appear non-conductive even after cleaning. For example, I cannot read the left-hand resistors R3 -R7 top or bottom, these should all read 220K. The other side is OK. I shall remove all solder and reflow, will also replace all the resistors on the left side. The oscillator coil L1 seems OK giving ohms reading. The IC as expected, had experienced corrosion to its legs, continuity checked all lead-outs top-side to solder pad print-side, leg 13 seems troublesome, not sure if this is the solder pad. Hopefully, after removing all solder and reflowing, it all might improve.

The keyboard PCB, many of these keys are not going to function, needs a good clean-up.

Chris, Glad you have sourced a replacement transducer. If you think I can help in any way please let me know.

Regards,

Oliver.