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Sobell TPS180, Rexine Heaven or Rexine Hell ?

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Marc
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Hi all,

A few years ago I acquired this little Sobell TPS180 television set with built in radio from our very own Chris and to be honest it's spent all it's time hiding under the bench collecting even more dust than it already had ! So I think it's time to drag it out and see if it can be saved.

The set is already slowly dismantling itself without any help from me eek_gif. The front is completely detached and it's original anchor points are long gone so something will have to be improvised for that. Looking in the back the dropper has been 'reconnected' for want of a better phrase and also the set is fitted with one of those special magic fuses wink

There are already one or two caps replaced in the time base but for the life in me I can't remember doing it, still never mind there's plenty more Hunt's to go at as we see what happens with some voltage applied. 

Popping the CRT on the B&K tester shows that there is some life in it, not a lot but enough.....I hope. hmm_gif

I hope to start working on the Sobell this week. Any way here are a few photos of the set......

Marc.

DSCF3992-Medium.JPG

DSCF3993-Medium.JPG

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DSCF3996-Medium.JPG

As you can see below the dropper has been errr 'reconnected' !

DSCF3997-Medium.JPG

And below one of those special magic fuses !

DSCF4003-Medium.JPG

But at least the CRT shows some life.

DSCF4001-Medium.JPG

Marc
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Posted : 05/03/2017 9:00 pm
crustytv
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marc said
A few years ago I acquired this little Sobell TPS180 television set with built in radio from our very own Chris and to be honest it's spent all it's time hiding under the bench collecting even more dust than it already had

Hi Marc,

I wondered what became of that little old set, I got it from Jon  who obtained it from an antiques market. I believe he did nothing to it then decided to have a clear out at which point I obtained it. Carrying on the tradition, I did nothing with it either, it just sat with me for a couple of years until I moved it along to your good-self.For some background on the actual set see here.

Maybe the set will be third time lucky and its new owner will finally give it the repair it deserves. I suspect both Jon and I will be following this one. thumb_gif

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Posted : 05/03/2017 9:09 pm
Katie Bush
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Friend o' mine has the TPS175, also with FM radio. I wonder how different they are.....duno_gif

Typically GEC double sided printed circuit boards too - those can be fun!

 
Posted : 05/03/2017 9:36 pm
crustytv
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Service data for the Sobell TPS180 has just been loaded into the library.

CrustyTV Television Shop: Take a virtual tour
Crusty's TV/VCR Collection: View my collection
Crustys Youtube Channel: My stuff
Crusty's 70s Lounge: Take a peek

 
Posted : 05/03/2017 9:46 pm
Marc
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Hi Chris,

Thanks for the data, that will be very handy. I'd already spotted the Sobell on Jon's site ages ago, in fact I'd almost forgotten about it. So this is a 'high millage set' Midlands to Durham to Yorkshire. smile

Hi Marion,

I've not seen a TPS175 but it would be interesting to see how alike it is to the TPS180. Oh yes the double sided PCB, batten down the hatches for some fun there wink

Marc.

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Posted : 05/03/2017 10:09 pm
Nuvistor
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There is not much room inside is there? I thought the back had crumbled but it looks just the paint peeling.

Look forward to watching it brought back to full working order.

Frank

 
Posted : 05/03/2017 10:14 pm
PYE625
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Hi Marc,

Looks like fun and will make a nice set when done. That dropper can be repaired. After you have secured the wire, heat resistant paint can hide the whole thing. 

To understand the black art of electronics is to understand witchcraft. Andrew.

 
Posted : 05/03/2017 10:28 pm
Marc
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Hi Frank,

Yes it is a little tight on space in there but at least the whole chassis & CRT slide out from the front of the cabinet. The back panel is in very sound condition it's just the paint pealing that makes it look poor.

Hi Andrew,

That dropper is actually still working but needs a better job making of it. I don't think I've got any VHT paint, I wonder what else I could use hmm_gif although i'll leave that job for later, let's see if the set can be fixed first.

Marc.

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Posted : 05/03/2017 10:43 pm
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marc said
 Oh yes the double sided PCB, batten down the hatches for some fun there wink

I have earplugs bang_gif

 
Posted : 05/03/2017 10:46 pm
Marc
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Cathovisor said

marc said
 Oh yes the double sided PCB, batten down the hatches for some fun there wink

I have earplugs bang_gif  

rolf_gif I can laugh now as I haven't started the job yet ! wink

Marc.

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Posted : 05/03/2017 10:51 pm
Marc
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Hi all,

Only a small amount of work today which consisted of de-frocking the chassis from it's cabinet, simple matter of removing 4 screws under the cabinet and 2 screws removed from the carry handle on the cabinet top, then twisting the chassis (left hand side from the front) outwards as if opening a door and away comes the 'gubbings' from the outer case. 

I now have access to the main 100/200uf smoothing can which hides in between the chassis and the CRT, it did look OK but the pip on the pitch seal was looking as if it was about to give way. I put the cap onto my *capacitor re-former but after several hours the cap was still drawing rather a lot of current so it looks like another re-stuff is on the cards.

*The capacitor reformer was built using parts from a junk box and based on the circuit from Paul Stenning's website....

  https://www.vintage-radio.com/projects/capacitor-reformer.html

Marc.

 

The 100/200uf cap looks fairly good......

DSCF4005-Medium.JPG

.....but not according to the capacitor re-former, 15mA leakage after several hours and not falling.

DSCF4007-Medium.JPG

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Posted : 06/03/2017 9:47 pm
PYE625
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marc said

*The capacitor reformer was built using parts from a junk box and based on the circuit from Paul Stenning's website....

  https://www.vintage-radio.com/projects/capacitor-reformer.html

Marc.

 I built the same thing ( a simple version without meters) and it is a very useful device. Your's looks the business Marc welld_gif

To understand the black art of electronics is to understand witchcraft. Andrew.

 
Posted : 06/03/2017 10:13 pm
PYE625
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Marc, are you able to measure the actual capacitance?

If so and both sections are low in value, you may have to consider a re-stuffing.  wink

To understand the black art of electronics is to understand witchcraft. Andrew.

 
Posted : 06/03/2017 10:28 pm
Marc
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PYE625 said

 I built the same thing ( a simple version without meters) and it is a very useful device. Your's looks the business Marc welld_gif  

 

I thought it would be really useful to have a dedicated re-former instead of taking up the 'Solar capacitor tester' and of course it doesn't even need to take up a DMM either. I have absolutely no idea what the box came from and likewise the mA meter but they go together well. I suppose if I came across a 350v DC meter I could add that too....that'd be really posh wouldn't it. grin_gif All in all I reckon there are probably loads of variants of that circuit all over the place by now and very good they are too.

Marc.  

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Posted : 06/03/2017 10:29 pm
Marc
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PYE625 said
Marc, are you able to measure the actual capacitance?

If so and both sections are low in value, you may have to consider a re-stuffing.  wink  

Yes and yes very low 1.2uf and 3.6uf....Turkey time me thinks grin_gif

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Posted : 06/03/2017 10:34 pm
Marc
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Hi all,

The main capacitor has now been re-stuffed and fitted back to the chassis, see here for details....  https://www.radios-tv.co.uk/forum/in-the-workshop/capacitor-re-stuff/

Power was slowly raised on the Variac and line whistle appeared by 170v and not long after it was joined by a crackle from the speaker then up came a blank but bright raster. Clicking through the channels causes flashing across the screen but other than a gentle back ground hum there is no sound.

A pleasing start so far but time to look round the RF stages. dmm_gif

Marc.

DSCF4031-Medium.JPG 

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Posted : 07/03/2017 5:38 pm
Nuvistor
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Focus looks good and it's nice and bright.

Frank

 
Posted : 07/03/2017 5:42 pm
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nuvistor said
Focus looks good and it's nice and bright.  

It sure does, looks like a corker Marc thumb_gif
 

To understand the black art of electronics is to understand witchcraft. Andrew.

 
Posted : 07/03/2017 6:40 pm
Marc
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Hi all,

I was pleasantly relieved to see how bright the CRT was, the B&K CRT tester does take a certain amount of interpretation to understand with monochrome tubes but she's never let me down yet.

More work on the Sobell hopefully tomorrow if I get the chance.

Marc. 

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Posted : 07/03/2017 7:06 pm
Marc
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Hi all,

Well I surprised myself tonight and managed to sneak in an hour or so at the bench. smile

I started by looking at the caps on the RF board which included 2 electrolytics (C40 1000uf & C80 5uf) and they looked very sorry for themselves so were taken out and tested.....both O/C, replacements fitted and power was applied again but this time with the appearance of more happening on screen (flashing on plain raster) but still only when changing channels. A click around both the Aurora's channel output and the telly tuner finally landed with a test card on CH3 so it appears that the tuner needs taking out of the set and giving a thorough clean/service to get reliable tuning, I wonder if this will help the absent sound fault too.

Looks like there are still issues to sort with picture geometry but it looks like this has the potential to be a very good set.

Marc.

DSCF4045-Medium.JPG

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Posted : 07/03/2017 9:59 pm
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