UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio 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 8th Jun 2006, 11:32 am   #41
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: Can somebody please repair My TV22

I am using one of the Velleman battery lcd scopes. but it says 100v max input.

Andi
__________________
Life is long, life is short, both of these a daunting thought.
Courtney Louise is offline  
Old 8th Jun 2006, 11:49 am   #42
Sean Williams
Dekatron
 
Sean Williams's Avatar
 
Join Date: Feb 2005
Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW
Posts: 3,024
Default Re: Can somebody please repair My TV22

Hmm, I wouldnt use this for TV servicing.

How about using a crystal earpiece - stick a 1000v cap on the centre pin of the earphone plug, and probe the oscillator grid to listen for a buzz.... - you will not need it in your ear, as it will be quite loud.....

Time to get a cheap valved scope me thinks

Cheers
Sean
__________________
Engineers make things work and have spare bits when finished
Sean Williams is offline  
Old 8th Jun 2006, 11:57 am   #43
ppppenguin
Banned
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Can somebody please repair My TV22

And a 10:1 probe. This will allow you probe up to several hundred volts without damaging the scope.
ppppenguin is offline  
Old 8th Jun 2006, 6:57 pm   #44
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: Can somebody please repair My TV22

My Velleman has a 10:1 switch on it...
__________________
Life is long, life is short, both of these a daunting thought.
Courtney Louise is offline  
Old 8th Jun 2006, 8:52 pm   #45
ppppenguin
Banned
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Can somebody please repair My TV22

That's not the point. A 10:1 probe also gives much lower capacitance at the probe tip.
ppppenguin is offline  
Old 8th Jun 2006, 9:32 pm   #46
jim_beacon
Heptode
 
jim_beacon's Avatar
 
Join Date: Mar 2003
Location: Bishop's Waltham, Hants, UK.
Posts: 939
Default Re: Can somebody please repair My TV22

More importantly, if the instrument states 100V max input, then that is 100V max regardless of the setting of the x1/x10 switch. An external x10 probe will give you lower tip capacitance, and, in theory (depending on the spec of the probe), the capability of 1000V max input - more likely 500V.

I have a Telequipment D61 scope (dual channel, 10MHz, 5V/div max input, 8x10cm screen - a x10 probe will give you 400V) here which is surplus, and fairly close to cal. Yours for 20 inc postage if that helps. You should be able to get a couple of reasonable x10 probes for about 10 each.

Jim.
__________________
Jim Beacon G1JBG
www.g1jbg.co.uk
jim_beacon is offline  
Old 8th Jun 2006, 10:33 pm   #47
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: Can somebody please repair My TV22

OK Now I have had the strangest thing of all happen...

I have lost my white line accross the screen for some reason and also the HT, until I meter the first anode voltage, then it all goes back to normal....

I have checked it's not a loose tube end, as it also happens if I just loosen the negative probe off the chassis...

Answers on a postcard...

Andi
__________________
Life is long, life is short, both of these a daunting thought.
Courtney Louise is offline  
Old 8th Jun 2006, 10:35 pm   #48
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: Can somebody please repair My TV22

Hi Jim,

Thanks for the offer of the scope and let me see what I can find locally first as I will just come down and fetch it if nothing else appears..

Regards

Andi
__________________
Life is long, life is short, both of these a daunting thought.
Courtney Louise is offline  
Old 12th Jun 2006, 9:14 am   #49
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: Can somebody please repair My TV22

Hi again Guys...

Well while I am still having trouble with the frame circuit I was wondering if anyone had any ideas on how to restore the rubberised screen surround and what colour it should actually be? The paint on mine is very yellow due to smokers in the past.

ADMIN : Is there any chance we can rename this thread to be TV22 Restoration?

Regards

Andi
__________________
Life is long, life is short, both of these a daunting thought.
Courtney Louise is offline  
Old 12th Jun 2006, 4:56 pm   #50
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: TV22 Restoration

Hi again guys,

This is my last update on my TV22..

It's beat me...

Complete set of new valves, changed every capacitor, metered almost every resistor, checked the T4 and T5 and still have frame collapse and only get the line on the screen if I actually have my test meter attatched to the 1st anode of the tube.

Putting it back together and itll be on ebay tonight...

I tried but I think I will stick to radios...

Andi
__________________
Life is long, life is short, both of these a daunting thought.
Courtney Louise is offline  
Old 12th Jun 2006, 5:19 pm   #51
Sean Williams
Dekatron
 
Sean Williams's Avatar
 
Join Date: Feb 2005
Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW
Posts: 3,024
Default Re: TV22 Restoration

Hi Andi,

Very sad news.

You nearly have the set working now - It has to be worth slogging on with it.

Leave it for a few days, do something else, then come back to it.

If all else fails I am sure one of us would have a look for you.

Cheers
Sean
__________________
Engineers make things work and have spare bits when finished
Sean Williams is offline  
Old 12th Jun 2006, 5:27 pm   #52
jim_beacon
Heptode
 
jim_beacon's Avatar
 
Join Date: Mar 2003
Location: Bishop's Waltham, Hants, UK.
Posts: 939
Default Re: TV22 Restoration

Quote:
Originally Posted by Jarl Ayari
only get the line on the screen if I actually have my test meter attatched to the 1st anode of the tube.
this would suggest that part of the 1st anode circuit is not properly grounded - when you connect the meter, you are shunting the pin to ground with a large resistance.

Jim.
__________________
Jim Beacon G1JBG
www.g1jbg.co.uk
jim_beacon is offline  
Old 12th Jun 2006, 5:35 pm   #53
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: TV22 Restoration

Hi Sean, I do that every time I order parts...

Jim, The circuit shows the 1st anode is fed from the Metrosil and is buffered to ground by C28 .1uf cap, which has been changed and have checked the connection from that tag on the tag strip to the grounding tab on the chassis and it seems to be fine...

Andi
__________________
Life is long, life is short, both of these a daunting thought.
Courtney Louise is offline  
Old 12th Jun 2006, 7:18 pm   #54
ppppenguin
Banned
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: TV22 Restoration

Surely there must be one of us up Brum way who can give some hands on help to Andi.
ppppenguin is offline  
Old 12th Jun 2006, 7:22 pm   #55
Sean Williams
Dekatron
 
Sean Williams's Avatar
 
Join Date: Feb 2005
Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW
Posts: 3,024
Default Re: TV22 Restoration

Hi Andi,

I have had this problem with a metrosil on a Cossor set I was playing with - Perhaps the metrosil is getting a bit flaky, or a dry joint on the tube pin perhaps?

If you and the set are going near Hitchin i could take a look with you, or why not bung it in a cupboard, and take it to the next Radiophile workshop?

Someone will crack it for you.....

Cheers
Sean
__________________
Engineers make things work and have spare bits when finished
Sean Williams is offline  
Old 12th Jun 2006, 7:26 pm   #56
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: TV22 Restoration

Hi Sean,

I had a spare metrosil and even tried the double diode thing from Andy's page and nothing. I had thought of the tube pin but I can croc clip the probe to the tube pin in question, or even just touch it and it does the same. But... If I prod the pin with a screwdriver (insulated of course) it makes no difference at all...

Andi
__________________
Life is long, life is short, both of these a daunting thought.

Last edited by Mike Phelan; 14th Dec 2007 at 8:26 am. Reason: Typos
Courtney Louise is offline  
Old 12th Jun 2006, 8:09 pm   #57
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: TV22 Restoration

OK Another update, When I attatch the meter to the 1st anode the line whistle frequency goes down in pitch too...

Andi
__________________
Life is long, life is short, both of these a daunting thought.
Courtney Louise is offline  
Old 12th Jun 2006, 9:31 pm   #58
Sideband
Dekatron
 
Sideband's Avatar
 
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 4,496
Default Re: TV22 Restoration

Quote:
Originally Posted by Jarl Ayari
OK Another update, When I attatch the meter to the 1st anode the line whistle frequency goes down in pitch too...


Something mighty odd there Jarl . Not looked at the circuit but I would assume the A1 volts are around 400v. So your Avo should ideally be on the 1000v setting. This presents quite a high impedance to the A1 supply and I would not have thought that this would 'load' the line stage as your description above implies. I could understand a shorted A1 decoupling capacitor loading the line stage but an Avo or a Fluke ??

I think you need to re-check connections somewhere.


Rich.
__________________
'And, in the end, the love you take is equal to the love you make'
The Beatles.
Sideband is offline  
Old 12th Jun 2006, 10:34 pm   #59
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: TV22 Restoration

Hi,

300v is what they say it should be and I get around 140v with a really bright line.

When I take the probe off I lose the line and the HT whistle changes too.

I have changed every cap and checked for broken wires etc and found nothing...

I am stumped...

Andi
__________________
Life is long, life is short, both of these a daunting thought.
Courtney Louise is offline  
Old 12th Jun 2006, 11:07 pm   #60
Courtney Louise
Heptode
 
Courtney Louise's Avatar
 
Join Date: Sep 2005
Location: Birmingham, West Midlands, UK.
Posts: 853
Default Re: TV22 Restoration

Hi Again,

OK Latest update...

I HAVE A FRAME!!!!!!!!!

While checking all the decoupling caps to make sure they were earthed to chassis, the ones on the side board weren't. Very odd; what had happened was the wire from the tagstrip that goes to the earthy pin of T4 had broken clean with the pin so when you lifted the board out the rubber sleeving was still close to the tag so didnt look broken.

OK, so just need to find the A1 problem and I can start work on the IF board...

It has been saved from Ebay lol.

Thanks guys for giving me the kicking I need...

Andi
__________________
Life is long, life is short, both of these a daunting thought.
Courtney Louise is offline  
Closed Thread

Thread Tools



All times are GMT. The time now is 3:38 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 - 2017, vBulletin Solutions, Inc.
Copyright ©2002 - 2017, Paul Stenning.