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 Kriesler 79-2 dated June 1959.
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 Return to top of page · Post #: 1 · Written at 10:24:49 PM on 15 June 2017.
Kriesleral's Gravatar
 Location: Mile End, SA
 Member since 23 February 2014
 Member #: 1512
 Postcount: 21

Hello

I mentioned in another thread that I have had this TV for quite some time but have come to a bit of an impasse in it's restoration.

It's been a long time for a couple of reasons, one being that it's very difficult to work on, needing the whole cabinet upended as the chassis is fixed to the base (see photo) rather than a hinged board as in later models, meaning I have to work through the base with very little room and bent over - and I'm not getting any younger!

Another reason is that I have a lot of difficulty with colour-coded resistors, being red-green colour-blind, but this can be overcome by buying pre-packaged resistors and measuring them on the multimeter before installing. I did remove the chassis and tuner and controls completely from the cabinet to re-cap, but don't want to do this again and risk damage.

The complete re-cap brought it mostly back to life, minus the sound. After careful adjustment and connecting an agile modulator and set-top box the picture is quite good, but even with the brightness and contrast right up, it fades very slowly to a dim and unwatchable picture.

The picture tube is a replacement (see picture), so if I can assume that's not the problem, are there any suggestions as to what I should do next? I'll test all the resistors in the high tension and horizontal circuitry, but maybe there is some way of testing the CRT to find out if its any good? I don't have or know of any CRT testers which the forums for vintage TV in the USA seem to always have available. Is there a way of testing the CRT with a multimeter? How should I go about beginning to remedying the silence?

A lot of questions, and I'm pretty much amateur in this type of work, but have a later Kriesler 79-16 ( with a hinged swing-out chassis)operating perfectly in the living room! If it's the CRT then it's pretty much been a waste of time, I fear.

Hoping you can help,

Cheers, Alan.

Kriesler 79-2 Television
Kriesler 79-2 Television
Kriesler 79-2 Television
Kriesler 79-2 Television
Kriesler 79-2 Television


More photos:-

Kriesler Television
Kriesler Television
Kriesler Television
Kriesler Television


 
 Return to top of page · Post #: 2 · Written at 11:01:08 PM on 15 June 2017.
Vintage Pete's avatar
 Location: Cromer, NSW
 Member since 1 May 2016
 Member #: 1919
 Postcount: 564

Hi Alan,
I'm a Kriesler TV Fan too.
Got a nice 1962 in rosewood and I'm restoring a 1960 Kriesler Radiogram at the moment.
11 77.
I cant help you with electronics because I'm timber guy and only learning electronics,,,but there is a few Kriesler fans here so someone may be able to give you some pointers,
Pete
PS: I have a precedent that does that ! It fades to a black picture after 10 minutes too? I'm hoping its not the FB, its losing voltage.


 
 Return to top of page · Post #: 3 · Written at 3:22:45 PM on 16 June 2017.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 578

Very unlikely to be CRT. If it was, it would get brighter over time.

I suggest measure voltages on CRT cathode, G1 and G2, cold, then when warm, displaying the same image. The results of that test, listed, will tell me where your problem lies.

I made myself some angle brackets to allow the chassis to be accessed while running, similar to the 79-4 and later models.

There are posts on this forum about my experiences with my 79-2.


 
 Return to top of page · Post #: 4 · Written at 11:03:43 PM on 22 June 2017.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 4321

'After' photos uploaded.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
Brad.

A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 5 · Written at 7:28:03 PM on 23 June 2017.
Kriesleral's Gravatar
 Location: Mile End, SA
 Member since 23 February 2014
 Member #: 1512
 Postcount: 21

Thanks for posting the additional photos, Brad.

Ian, I'm not clear on what you mean when you say " measure the G1 and G2" on the cathode. Could you tell me at what points on
the circuit diagram I should make these readings? What the likely/ correct figure is?

Look forward to your response - the additional photos show a test pattern and the second last shows how it not only loses brightness, but collapses in the middle somehow..

Cheers.

Alan.


 
 Return to top of page · Post #: 6 · Written at 8:08:47 PM on 23 June 2017.
Vintage Pete's avatar
 Location: Cromer, NSW
 Member since 1 May 2016
 Member #: 1919
 Postcount: 564

Have you not got a schematic?
Monochrome on this site ,often helps out with schematics if he has them , he is very helpful .
Or keven chant has a site for free down loads of schematics if you need one,,pete


 
 Return to top of page · Post #: 7 · Written at 11:20:06 PM on 23 June 2017.
MonochromeTV's avatar
 Location: Melbourne, VIC
 Member since 20 September 2011
 Member #: 1009
 Postcount: 906

This TV in question is a model "Special Console" 121-14 from 1959.

All the relevant service details are already here:

https://vintage-radio.com.au/default.asp?f=6&th=143


 
 Return to top of page · Post #: 8 · Written at 8:03:19 PM on 25 June 2017.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 578

Cold volts Hot volts Should be (very approx)
-------------------------------------------------------------------------------------------------
Cathode CRT pin 11 114
G1 CRT pin 2 88
G2 CRT pin 10 420

You may need to temporarily disconnect C158 to get a sensible reading for CRT G2 because the horizontal blanking pulse will upset your meter which will give you a wrong reading. This connects to Pin 4 of the line transformer - NOT the wire that goes to the linearity control.

Post your results and I'll tell you where the fault is.

Make sure you refer to the 79/2 - 3 circuit. There are differences in this area. The 3 appears in the Issue number in the title block.


 
 Return to top of page · Post #: 9 · Written at 6:54:10 PM on 27 June 2017.
Kriesleral's Gravatar
 Location: Mile End, SA
 Member since 23 February 2014
 Member #: 1512
 Postcount: 21

Pete

Yes, I do have a schematic, dated 4th June 1959.

Ian

Thanks for the explanation - I now know what you are referring to, will measure and report,

Cheers, Alan.

Kriesler 79-2 Television


 
 Return to top of page · Post #: 10 · Written at 7:08:15 PM on 27 June 2017.
Kriesleral's Gravatar
 Location: Mile End, SA
 Member since 23 February 2014
 Member #: 1512
 Postcount: 21

Also,

Thanks to MonochromeTV for the link to the service details - will print and devour!

Cheers.


 
 Return to top of page · Post #: 11 · Written at 11:32:13 AM on 28 June 2017.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 578

My measurement table spacing got lost in the post formatting but I think you can still read it.

Measuring G2 when there is a blanking pulse present used to catch out a lot of techs who'd order a replacement CRT when the real fault was a resistor connecting the 400 or so volts on G2 from B+Boost. I was a service manager so I know! The mistake was understandable because not all early TVs had horizontal blanking.

An alternative to disconnecting the blanking (the danger in disconnecting things is you might do something unintended) is to make a low-pass pad for your meter. This is quite simple:

Connect a 100k or so resistor in series with your + meter probe.
Connect a capacitor of around 100nF (0.1uF) rated at at least 400 volts across the + and - of the meter.

Then, when you measure CRT G2, the effect of the blanking pulse will be removed.


 
 Return to top of page · Post #: 12 · Written at 2:23:10 PM on 24 August 2017.
Kriesleral's Gravatar
 Location: Mile End, SA
 Member since 23 February 2014
 Member #: 1512
 Postcount: 21

Hello Ian

I've been able to do some measuring of G! and G2, etc .and clearly something's wrong.

I have the following warm/ hot numbers :

For G1 134/165V which varies with brilliance;

For pin 11 199/207V which varies with contrast.

the G2 reading as is -for what it's worth- is 240/245V.

I've attached a photo of the state of the 1S2 EHT rectifier after removal when I first tried to start up this morning. The base of the tube separated from the body...I've never had this happen before! It's usually the cap which comes off - BTW any hints on re-attaching the cap?

Cheers, Alan.

1S2 TV Valve


 
 Return to top of page · Post #: 13 · Written at 4:42:51 PM on 24 August 2017.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 578

Hi Alan
I'm currently in Lyon (France) and writing this on a tablet!.
G2 is much too low so you should check resistors around there.
Another reason for low G2 is the boost cap - that's the one attached to the EHT transformer under the strap thingy. You need to replace this with a suitably high voltage part if you haven.t already.
You said something about the picture collapsing, that would be consistent with boost cap leakage.
Although I see now it.'s been replaced.

To re-attach the 1S2 cap:

Hold the cap by the edge with long nose pliers and melt the solder.
Flick it to remove the solder. A hole appears.
Apply a small qty of two part epoxy mixed to the inside on the cap.
Fit the cap, poking the wire through and solder.

Sometimes it helps to enlarge the hole.


 
 Return to top of page · Post #: 14 · Written at 5:01:25 PM on 24 August 2017.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 4321

G'day Ian,

Slightly off-topic but a pertinent question, how does VR load all the way over in France and are you experiencing any errors?


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
Brad.

A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 15 · Written at 6:43:23 PM on 24 August 2017.
Kriesleral's Gravatar
 Location: Mile End, SA
 Member since 23 February 2014
 Member #: 1512
 Postcount: 21

Enjoy France, Ian and thank you for taking the time to respond while there.

Cheers.


 
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