Teak Acoustic Deluxe. RBM 640 Basket Case!

[1100 man]

Fantastic!! I just knew you would have to do it orange- looks brilliant. Picture could do with some work though...
All the best
Nick

[Graham G3ZVT]

Wow, that cabinet repair is worthy of Ted de Pol.

I should explain Ted had the position of Regional Polisher in the '70s when I started at GTVR. I can't remember his surname, we knew him as Ted de Pol.
What he couldn't do with a cabinet.
So if you accidentally rolled someones pride & joy in the back of your Vauxhall Viva, or damaged a set in the workshop, Ted would be your saviour.

His party-trick was removing the ring left by a cup or vase by wiping meths onto the cabinet and setting light to it, it always worked for him but whenever we tried it was a different story.

[Hybrid tellies]

I had the olive green version of this model. it needed a new LOPT and gave great results. Fantastic sound on it and everyone commented on how cool it looked. I wish I had not sold it on to a friend. I heard it was still working well and looking good nearly 20 years later.

[Tazman1966]

I'm absolutely bowled over! A fantastic job. As I said somewhere else, this was the colour of the one that I dumped over 30 years ago

[Colourstar]

Yes I'll second that! It looks absolutely amazing, Mick.

Was the chassis as crusty as the cabinet?

Steve

[MickMcmichael]

Hi Steve

Yes, in places. The tuner was almost rusted solid. I've used one from a scrap chassis.

There are some rust spots behind the chassis on the system switch lever. The 405/625 system switching cable is missing and I've had to use one from a different model and re-invent a system of mechanical switching. I'll take a photo of that in due course and give you all a laugh.

As my service controller at British Relay used to say: "Any form of bodgery shall be known as a modification!"

My supervisor used to say: "If you can't fix it then try and find a way to make it work!"

And after whatever I'd done, someone would say: "That's a bit Heath Robinson, Mick!"

Well my system switch cable arrangement works and it's a combination of all three of the above. I'll post a picture in due course.

Thank you all for your comments. So far it's been a lot of work and I'm enjoying every minute of it. The lopt problems will be the first to be tackled.

[FERNSEH]

Outrageous Orange! the best choice of colour for the set. Anything else would be just plain ordinary.
All you need now is the pillar stand for this model. I kinda remember it was the Rank-Bush-Murphy type A772?

DFWB.

[Colourstar]

Mick's orange set is quite tame compared to what Murphy were offering buyers at the time. From the London trade shows during the summer of 1968, Practical Television magazine reports:

"Murphy had a number of brightly coloured black-and-white sets. They are produced in a variety of designs ranging from abstracts to pop art. The first receiver to be available in quantity has its cabinet painted in a leafy pattern in shades of red, brown, orange and yellow on a white background. Another set in the range has the names of television programmes painted in red and blue letters on the cabinet. These receivers have 23" tubes and will retail at 100gns"

Sadly there are no photos to back this up! I did wonder if they were produced especially for the shows, but the line 'the first receiver to be available in quantity' suggests at least some were not one-offs. What became of them all?

Steve

[ntscuser]

Originally Posted by MickMcmichael

Here we are then. Skimmed, sanded and smooth, primed and sprayed.

Great job so far

The primer coat makes it look like the 'Smooth Blue' version of the set!

[MickMcmichael]

So here's the system switching arrangement. This hasn't been easy due to the fact that the switching cables, brackets and levers are different from model to model. A lot depends on whether the tuner is vertically or horizontally mounted and how far away it is from the main chassis.

Some A640 models simply used a lever and a strong piece of thick steel wire coupled between the tuner and a lever bolted to the chassis near the system switch bar by the IF board.

My white acoustic deluxe (19") uses two cables strapped together on a steel bracket below the tuner which is mounted much closer to the chassis than in the 23" version.

I only had scraps from various chassis so I made do! The block of wood stops the aluminium bracket I made (that's all I had) from moving under pressure when the tuner activates 405/625. That way switching is achieved without having to press the tuner buttons umpteen times before switching can be activated. I used a single connection out of a piece of barrier strip to anchor the cable from the tuner to a piece of steel wire which goes to the lever on the chassis.

I don't think I'll win any prizes for design innovation for this but at least it works, which is all I'm bothered about.

The lopt was made up from two. I had one that had a good overwind but the transformer was duff on 625 and one with a good transformer and a duff overwind so I made one out of the two.

The only component I had to replace on the chassis was 3R36 which is a 680K half watt which feeds boost directly to the frame stage. It had reached 1.4 meg and the height was a little reduced. A couple of the valve bases need cleaning (the PCL82 is the roughest) and I need to refit the lopt screening.

The tube is a little soft as you can probably see and I might fit a heater transformer with 20% boost to deal with that. I'm certainly not at this stage going to boost the tube.

The test card picture was taken on 405 and the snippet from All Creatures Great and Small was taken on 625. That's probably the second time in the sets' life that it has displayed that very episode!

The picture of the oversized test card which I posted earlier in the thread was the lopt that had the duff transformer (overwind was good). The symptom it gave was oversized picture on 405 and badly damped line (and no EHT) on 625.

Many thanks to Rich who let me have this set for spares. When he brought it round he said: "You might want to be careful - the cabinet is a bit poor!"

[Graham G3ZVT]

The bowden cable passing through the barrier strip terminal is exactly the way I formed the new eyelets on my up & over garage door when the original crimped ones failed.

I had quite forgotten how I hated working on that particular chassis.

[Nickthedentist]

Just wanted to say well done on the heroic cabinet restoration too!

I would have thought that it needed re-making rather than restoration.

[Heatercathodeshort]

Well worth all the effort. A great result. John.

[Peter88gate]

If this forum awarded prizes for cabinet restoration of basket case sets, then I think you would have won the 2017 award!

A really magnificent job.

Amazing that the electronics were so relatively straightforward in comparison.

Peter

[Hybrid tellies]

An excellent job, brilliant cabinet restoration.

[Welsh Anorak]

Looks great! I would be tempted to boost the tube gently rather than over-run the heaters. I've found in the past that these CRTs respond well to a quick boost - just once then run the set for an hour. It usually works - and if not there's always the transformer...
Reminds me that when i was at school I acquired a Bush TV171 and painted the cabinet orange! Well, it WAS the seventies.
Glyn

[slidertogrid]

The transformation is incredible!
It never occurred to me to try to repair the cabinet. I had considered asking a friend with wood working skills to reconstruct it in MDF using the original cabinet as a pattern and donor for the internal wood blocks etc.
However I decided it was never going to happen and donated the set to Mick for some parts.
It was rescued from a damp leaking shed along with a few other sets (that had faired better) a couple of years ago.
I doubt it has been used for a decade or more so maybe the tube will improve with use.

The "Unit-Plan-Chassis" was launched in 1966 The original models being the "green label" !9" Bush TV141U and the "red label" 23" TV148U. This was the earlier chassis with the valve IF and separate tuners. As mentioned earlier by Neil.
I have a TV148U in my collection, the tuners are mounted in an escutcheon on the top. the system switch on the front. you have to be careful changing systems it's easy to push the set backwards such is the force needed!
Interestingly the original sets were available at a reduced cost without UHF tuner.
There is a small article in "trade News" in the August 1966 Practical Television magazine proudly announcing its debut.

Well done Mick!
When you get bored with it let me know...

Rich.