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-   -   Is it a Bush TUG.68 ? (https://www.vintage-radio.net/forum/showthread.php?t=105321)

boxdoctor 30th Apr 2014 2:19 pm

Re: Is it a Bush TUG.68 ?
 
The setting of the mains voltage selector shown in post#2 does not bode well - unless you have altered it yourself :o Tony.

HamishBoxer 30th Apr 2014 2:30 pm

Re: Is it a Bush TUG.68 ?
 
Not ideal but not convinced it would take out the overwind.

Heatercathodeshort 30th Apr 2014 3:10 pm

Re: Is it a Bush TUG.68 ?
 
This is indeed odd. If the EHT overwind is O/C within the winding it would arc furiously when operating. If it is not arcing the EHT rectifier should still be lit if the line timebase is functional. You do not need the overwind to light the EY86/EY51. I presume you have continuity between the PL81 and PY81 top caps? J.

ekcopyephilips 30th Apr 2014 4:45 pm

Re: Is it a Bush TUG.68 ?
 
Hi Stubble

If you want, i have a LOPT from a TV53 which is exactly the same that is yours if you want it. I have done a ringing test on it and it seems to be OK, but never had any power applied. Let me know if you want it.

Mike

Stubble 1st May 2014 10:11 am

Re: Is it a Bush TUG.68 ?
 
Hi chaps

I think my next move is to sort out the rubber wire, only four or five cables need changing and fit a new mains cable.

I will then see if the heater chain works and then I will refit the original LOPT and see what happens when I show it some mains and be ready for some fire works. 8-o
What I am hoping for is the time base will start (fingers X) and a line whistle can be heard and the EY86 heater will hopefully come up too with out any drama.

@ekcopyephilips

Hi Mike
I will try the original LOPT first and see what transpires and if it is a dud I would very much like to take your very kind offer up, much appreciated and many thanks, Lee :thumbsup:

Stubble 2nd May 2014 2:08 pm

Re: Is it a Bush TUG.68 ?
 
3 Attachment(s)
Stage one of rubber wire replacement, the receiver unit.

I had hoped to re-used the original cotton sleeving to cover the three cables but it was so rotten and kept breaking and tearing so I gave up on that one.

The rubber insulation was in a very poor state, had I shown it some mains it would have ended with a bang for sure.

Next, the same treatment for the main deck.
What is it that degrades the rubber on the upper parts more than those on the under side, I assuming it’s the acids in the dust from pollution?

mark pirate 2nd May 2014 3:08 pm

Re: Is it a Bush TUG.68 ?
 
The upper deck wiring is usually worse as it is affected by heat, bad storage also plays it's part. I have restored two Bush TV22's, both from 1950.
one was stored in a loft for years, the other was stored in a bedroom, no prizes for guessing which one needed rewiring!
:beer:
Mark

Stubble 3rd May 2014 8:36 pm

Re: Is it a Bush TUG.68 ?
 
Bet it was the one in the bed room!!

Stubble 4th May 2014 3:44 pm

Re: Is it a Bush TUG.68 ?
 
5 Attachment(s)
Phase two of the rubber wire replacement, main chasses.

As can be seen in the first photo showing this some mains would have been suicide.
I had to think for a while on how to fish the new wires in under the tag board, so I ended up replacing one at a time, soldering the end of the old to the new and gently pulling the new though, worked a treat.

Isolated the original mains connecting pins and drilled a hole in the chasses, fed in new mains cable and grommet, connecting directly to the power switch.

So it’s all system go for tomorrow and seeing if first light can be obtained.

Lee :thumbsup:

jay_oldstuff 4th May 2014 6:35 pm

Re: Is it a Bush TUG.68 ?
 
Very nice work so far. I tend to use the same method for pulling new wires into position as you described and it does indeed work very well.

Jay

Stubble 5th May 2014 2:00 pm

Re: Is it a Bush TUG.68 ?
 
5 Attachment(s)
Good afternoon all,
Both chasses refitted into the cabinet and connected up this morning.

Removed the HT fuse No2 and applied some mains for the heater chain all started to come up but then died out after a few seconds except V5, V8 and V9 power off quick, a bit of head scratching and a revisit to the circuit diagram, ho C38 .05uf had become a dead short, red hot and dripping wax so snipped one end out of circuit.

Reapplied power and all heaters came up nicely, I them left running for five minuets.

HT fuse reinstalled and power reapplied, smoke from the droppers, lovely aroma fills the garage. After what seemed like an age a very faint and I mean faint line whistle which was like a cat being strangled five miles away, the line hold pot did alter the faint pitch of the whistle but it wasn’t enough to light the EY86 heater either and no sound from the speaker.

So the recapping of the line output will commence when the order of capacitors arrives hopefully at the end of this week.

Lee

mark pirate 5th May 2014 2:48 pm

Re: Is it a Bush TUG.68 ?
 
Looking good :thumbsup:
Thankfully most of the wiring on the set is PVC, or it would take you hours to replace!
My latest set has no rubber wiring to replace, it even produces 5.5Kv EHT.
The bad news is that it uses the HMV 1807 chassis :wall:
:beer:
Mark

Focus Diode 5th May 2014 4:45 pm

Re: Is it a Bush TUG.68 ?
 
Brilliant work so far. The EY86 looks as if it's lit up on your photo, but probably a reflection from somewhere else.

Looking forward to hearing more.
Cheers,
Brian

HamishBoxer 5th May 2014 5:20 pm

Re: Is it a Bush TUG.68 ?
 
Yes,i agree that EY86 does indeed look to have its heaters working.

Heatercathodeshort 5th May 2014 5:32 pm

Re: Is it a Bush TUG.68 ?
 
I think the glow is a reflection. The light can be seen on the 'bell' anode. It should be a bit further forward towards the base end. J.

Stubble 5th May 2014 6:31 pm

Re: Is it a Bush TUG.68 ?
 
Hi chaps

The glow is a reflection in the glass envelope of the EY86 most likely from the two rectifier PY82's nearby.

Lee :wave:

Stubble 11th May 2014 2:16 pm

Re: Is it a Bush TUG.68 ?
 
Afternoon all,

Had some more time today, fixed the wiring to the speaker which someone had previously butchered (why I just don’t now, both had been cut and twisted together) so we now have sound, well I mean humming.

The only two cap’s I have left in stock at the moment .1 and .01uf have now been fitted into the line time base C20 and C23. Now have a stronger line whistle and the heater is lit in the EY86 but no EHT not a glimmer, no spark no nothing.

Can’t run the set long as some of the waxies in the frame time base are bubbling and smouldering.

More soon.
Lee

Stubble 11th May 2014 4:04 pm

Re: Is it a Bush TUG.68 ?
 
Couldn’t leave it alone, connected the Aurora, selected channel 4 on the set which the Aurora is set too.

Switch on and the test tone can be heard for the first time, interlaced with the humming from all those leaking cap’s.

Chuffed to bit’s with this…;D

HamishBoxer 11th May 2014 4:28 pm

Re: Is it a Bush TUG.68 ?
 
Could well come back to the EHT overwind.You would certainly get EY86 heaters being ok if the overwind is faulty.

Heatercathodeshort 12th May 2014 6:43 pm

Re: Is it a Bush TUG.68 ?
 
This does not make sense. If the EY86 is lit, there must be EHT at the anode end from the transformer overwind. If not this can only be due to an open circuit/break of some length as small break would result in sparking and smoke due to arc over. How are you checking the DC EHT? You need to short one end of the screwdriver to chassis and bring it very close or actually touch the CRT connector, the metal bit of course. It should crack over but will do no harm. The AC end can be checked by simply dragging a screwdriver tip over the feed end of the EHT overwind [EY86 top cap]. There is no need to earth the screwdriver for this test. Replace all the wax caps in the line oscillator and output stage before delving too deep. Tick them off the circuit as you work as I think there are a couple UNDER the tag boards. I wish I had that chassis on my bench! Interesting symptoms. Regards, John.


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