UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Television and Video

Notices

Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc.

Closed Thread
 
Thread Tools
Old 7th Jan 2017, 12:05 pm   #1
FERNSEH
Dekatron
 
FERNSEH's Avatar
 
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
Default Bush TV32 needs a replacement CRT.

Just like the TUG26 which is being discussed in this forum this TV32 also has a worn out CRT. The TV32 was serviced last year but the job couldn't be fully signed off because the CRT is for intents and purposes useless.
Without delay the search was on for a replacement MW36-24 CRT this proved not to be an easy task. It would seem that 14" rectangular CRTs are even more scarce than the 12" roundies. After many searches a complete Sobell T143 appeared on an on-line auction website, the seller was willing to post it so I decided it was worth the gamble, the CRT might be good. The set arrived in good condition. But first the set had to be fully serviced so that the CRT condition could be assessed, the gamble paid off, the CRT displays really bright pictures just like a new tube. The CRT will be removed from the Sobell and used as the replacement for the worn out tube in the Bush.

So what will happen to the Sobell? Worry not I've got plans for it, it will display pictures again. The magnetic focus CRT will be replaced with an electrostatic focus Mullard AW36-20. This will necessitate removal of the focus magnet assembly and a new support bracket will be made for the CRT neck components.
This will be introduced in a new topic.

DFWB.
Attached Thumbnails
Click image for larger version

Name:	DSC_0144_7.jpg
Views:	209
Size:	45.8 KB
ID:	135490  
FERNSEH is offline  
Old 7th Jan 2017, 1:42 pm   #2
Vauxfan2k
Hexode
 
Join Date: Aug 2016
Location: Inverness, Highland, UK.
Posts: 300
Default Re: Bush TV32 needs a replacement CRT.

Hi, I've been reading your posts with a great deal of interest, while all the work you carry out is way beyond my skills, I have a question regarding the future use of the sets that you successfully repair. As analogue tv is now a thing of the past, what analogue source of input do you use on these sets? Vcrs and the like obviously lose quality and sharpness so don't really give a signal that the TVs potential can display. Is it possible to broadcast your own short range analogue signal (in the correct formats) that the tuner can receive? Or does that require a license and specialist equipment?

Cheers

Steve
Vauxfan2k is offline  
Old 7th Jan 2017, 2:02 pm   #3
Nuvistor
Dekatron
 
Nuvistor's Avatar
 
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,427
Default Re: Bush TV32 needs a replacement CRT.

Feed a DVD player, Freeview box into one of these and connect to the Vintage TV., no transmission or licence.
http://www.tech-retro.com/Aurora_Design/SC_images.html

Or this version
http://www.tech-retro.com/Aurora_Des...Converter.html

Frank
Nuvistor is offline  
Old 7th Jan 2017, 4:26 pm   #4
Top Cap
Octode
 
Top Cap's Avatar
 
Join Date: Mar 2006
Location: Watford, Hertfordshire, UK.
Posts: 1,270
Default Re: Bush TV32 needs a replacement CRT.

Such a shame when one reads old copies of Radio Constructor etc., to see so many places offering CRT re-gunning yet all have now disappeared. I often wonder how they learnt to re-gun and cannot imagine anyone buying costly plant to do this but I guess it was financially worth while. We need Doctor Who to take a few crt's back to 1960!
__________________
Whether the Top Cap is Grid or Anode - touching it will give you a buzz either way!
Top Cap is offline  
Old 7th Jan 2017, 8:43 pm   #5
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Bush TV32 needs a replacement CRT.

Quote:
Originally Posted by FERNSEH View Post
So what will happen to the Sobell? DFWB.
Now you have ripped it apart and stolen it's very soul, I feel you should bid it a brave farewell.
Float it down the Tyne with one of those flashing, red domed Pifco handlamps strapped to the top of the case.
You know the type that lacerates your hand when you attempt to unscrew the back to replace the 996 battery. That will guarantee safety to shipping.

The Sobell will accept the AW36-20/21 nicely. Pity you have to make an adapter plate to support the tube neck. These simple things take time. If you need a picture shift device to replace the old focus magnet and shuffle plates, let me know. I'm sure I have a couple somewhere with some spare ion traps. Good luck with that TV32. I bet it turns out to be a cracker with that tube! Regards, John.
Heatercathodeshort is offline  
Old 7th Jan 2017, 9:00 pm   #6
FERNSEH
Dekatron
 
FERNSEH's Avatar
 
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
Default Re: Bush TV32 needs a replacement CRT.

Even if the regunning plant could be found I reckon it would be a brave person who is willing to take a chance on such a venture. Somewhere in these islands there must be CRT regunning equipment hidden away just waiting to be re-commissioned.
Returning to the TV32. According to the rules of Glasnost (openness) I must report after fitting the replacement CRT the neck of the tube does not line up with the chassis mounted focus magnet. The CRT is mounted separate from the chassis. A high degree of assembly accuracy is demanded with this set.
I'll return to the later today.

DFWB.
FERNSEH is offline  
Old 7th Jan 2017, 9:44 pm   #7
FERNSEH
Dekatron
 
FERNSEH's Avatar
 
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
Default Re: Bush TV32 needs a replacement CRT.

Hi Vauxfan2K,
Yes, I understand what you inferred to. At the present time Freeview boxes and DVD players have PAL625 outputs which we can feed to our standards converters but it won't be too long before such devices will have only HDMI outputs. Fortunately, HDMI to PAL converters do exist, buy one before it's too late.

DFWB.

Last edited by FERNSEH; 7th Jan 2017 at 10:06 pm.
FERNSEH is offline  
Old 7th Jan 2017, 11:40 pm   #8
FERNSEH
Dekatron
 
FERNSEH's Avatar
 
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
Default Re: Bush TV32 needs a replacement CRT.

That's more like it. The picture is really bright, just like it was in the Sobell T143.
The corner brackets of the CRT mounting assembly needed adjustment to reposition the tube in the cabinet in order that the focus magnet is centralised about the tube neck.
The set takes an inordinate long time to warm up, more than three minutes. The TUG26 had that problem and to speed up warm up time the heater chain thermistor was replaced with a Mullard VA1026. Also, the PY81 boost diode might be the old type with the ceramic sleeve over the heater, very slow warm with this valve.
The tube is excellent and to keep it in this condition the mains voltage settings should be checked so that 6.3 volts is measured at pin 1 and 12 of the CRT socket.

DFWB.
Attached Thumbnails
Click image for larger version

Name:	DSC_0115_8.jpg
Views:	229
Size:	55.9 KB
ID:	135562  
FERNSEH is offline  
Old 7th Jan 2017, 11:54 pm   #9
julie_m
Dekatron
 
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
Default Re: Bush TV32 needs a replacement CRT.

No doubt there will be a next-generation Aurora-like device which will be able to convert from HDMI to various obsolete standards, though .....
__________________
If I have seen further than others, it is because I was standing on a pile of failed experiments.
julie_m is offline  
Old 7th Jan 2017, 11:57 pm   #10
Hunts smoothing bomb
Octode
 
Hunts smoothing bomb's Avatar
 
Join Date: Oct 2005
Location: Wimborne, Dorset, UK.
Posts: 1,407
Default Re: Bush TV32 needs a replacement CRT.

That looks more like it, what a really good tube that is!

Cheers
__________________
Lee
Hunts smoothing bomb is offline  
Old 8th Jan 2017, 12:10 pm   #11
line sync
Heptode
 
Join Date: Sep 2009
Location: Kinver, Staffordshire, UK.
Posts: 628
Default Re: Bush TV32 needs a replacement CRT.

That's a job well done david , that picture looks really good.
I knew some body who had 14" crt , perhaps I should chase him up and see if he`s still got it.

Robin
line sync is offline  
Old 8th Jan 2017, 12:34 pm   #12
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Bush TV32 needs a replacement CRT.

Nice result David and well worth all your hard work. They must have used jigs at the factory to line up the tubes.
Mind you my pet Orangutan 'Flyback' has become very adept at changing tubes but so far I have not had the courage to stay in the workshop when he does it. He can set an ion trap in 15 seconds.
The slow warm up can be a bit frustrating with all Bush receivers. The old style PY81 takes a very long time to wake up.. The later PY81 and PY800 solved that problem completely but without the ceramic sleeve maybe with a lesser margin of safetywith the heater cathode insulation.
MaybeI think the long warm up reduced the stress on the valves and added to the long life of these chassis.
The original PY81 from Mullard was quite a little miracle. 4.5kv heater cathode insulation in 1950, something that the other valve makers took a very long time to match.
Mazda released a very odd range of booster diodes such as the U281/U282. These required a separate winding on the mains transformer to supply the heaters. Even the 1953 octal based U301 was a disaster with a flaking cathode causing flash over. This was such a serious problem that Murphy and Ultra modified their chassis to fit the B9A PY81 or GEC near equivalent as it took Mazda so long to solve. [they never did completely until later versions of the U191 were released in 1959]
Mullard [Philips] certainly had the edge on overall valve development but saying that Mazda produced some of the very best RF pentodes, power output valves, general purpose triodes and high gain tuner VHF tuner valves.
That Bush needs a long hard soak test [no not in the Tyne..] to seek out any lurking snags. Other than that, put the back on, write an invoice and put it in the back of your Ford E93A van for delivery.
Oh, don't forget to put the ladders on the roof rack. The 'H' aerial may need to be moved from the chimney at the front of the house to the back one to help reduce ignition interference. Don't fall off the ladder. Bye, John.
Heatercathodeshort is offline  
Old 8th Jan 2017, 5:58 pm   #13
wd40addict
Octode
 
wd40addict's Avatar
 
Join Date: May 2009
Location: Stevenage, Herts. UK.
Posts: 1,515
Default Re: Bush TV32 needs a replacement CRT.

HDMI is an expensive club to join: http://www.hdmi.org/manufacturer/terms.aspx

I don't think anyone will be rushing out an HDMI > 405 converter any time soon.
wd40addict is offline  
Old 8th Jan 2017, 6:54 pm   #14
FERNSEH
Dekatron
 
FERNSEH's Avatar
 
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
Default Re: Bush TV32 needs a replacement CRT.

I didn't realise the HDMI license was that expensive. Although if a manufacture is producing vast quantities of some audio visual item $10K can be paid out of the petty cash box. At the moment there is nothing to worry about but we have to think about the future.

DFWB.
FERNSEH is offline  
Old 8th Jan 2017, 6:58 pm   #15
julie_m
Dekatron
 
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
Default Re: Bush TV32 needs a replacement CRT.

And the Chinese will only need to pay for one licence between them all anyway .....
__________________
If I have seen further than others, it is because I was standing on a pile of failed experiments.
julie_m is offline  
Old 8th Jan 2017, 7:09 pm   #16
FERNSEH
Dekatron
 
FERNSEH's Avatar
 
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
Default Re: Bush TV32 needs a replacement CRT.

I've just ordered an HDMI to PAL/NTSC converter from an online seller located in Consett, County Durham. Not far from my location.
Will report my findings about this device in the in the "Television standards converters, Modulators etc" section of the forum.

DFWB.
FERNSEH is offline  
Old 10th Jan 2017, 2:09 pm   #17
Brigham
Octode
 
Join Date: Mar 2006
Location: Co. Durham, UK.
Posts: 1,111
Default Re: Bush TV32 needs a replacement CRT.

Is that likely to be an unauthorised device? I can't see such a converter being a major profit line.
Unless it's a sideline from one of the existing 'adopters'.
This is looking more and more like a big-business stitch-up...
Brigham is offline  
Old 10th Jan 2017, 4:42 pm   #18
cmjones01
Nonode
 
Join Date: Oct 2008
Location: Warsaw, Poland and Cambridge, UK
Posts: 2,669
Default Re: Bush TV32 needs a replacement CRT.

As I understand it, the hard part about HDMI is actually HDCP, the encryption that's supposed to make sure that only 'authorized' equipment is able to display protected high-definition content from Blu-ray and the like. I won't comment on the politics of this.

There is no reason at all why a device with an HDMI socket on it can't just display or convert non-protected content from a computer or other device. Electrically, the HDMI socket is almost the same as the DVI connector used on computer monitors. As I understand it, standard-definition content generally isn't protected anyway, so a converter from HDMI to standard PAL or NTSC should be no problem for the foreseeable future. Good news for the vintage TV community!

Chris
__________________
What's going on in the workshop? http://martin-jones.com/
cmjones01 is offline  
Old 10th Jan 2017, 9:29 pm   #19
FERNSEH
Dekatron
 
FERNSEH's Avatar
 
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
Default Re: Bush TV32 needs a replacement CRT.

The HDMI to PAL converter unit arrived yesterday, unbelievably fast delivery considering it was only ordered on Sunday evening.
A USB power supplier is required.
I'll report my findings about this device in the Standards Converters and Modulators section of the forum.

Getting back to the Bush TV32. The picture is excellent, the only issue are the occasional clicks and plops from the loudspeaker. Today, hoping to find a cure I changed a few waxies in the sound stages, although the TCC capacitors were leaky there was no improvement to sound performance.

DFWB.
Attached Thumbnails
Click image for larger version

Name:	DSC_0156_8.jpg
Views:	109
Size:	44.0 KB
ID:	135743   Click image for larger version

Name:	DSC_0157_4.jpg
Views:	95
Size:	42.5 KB
ID:	135744  
FERNSEH is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 7:54 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.