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Retired · 13th Sep 2011, 5:14 pm

Hi,

Today started early; I was wide awake in bed at 5.15 this morning fighting the urge to get into the workshop.

As caps play such an important role and this chassis was full of waxy caps I've spent the morning changing them rather than taking a lot of time trying to identify each one. Every cap I replaced was leaking badly on test. I used 630V units throughout with the exception of a Metalpack Visconol 0.02uF rated at 750V on a large transformer so I used a TCC Supermold 0.022 rated at 1500VDC.

All the caps removed were leaking badly on the 100/200V range of the Hunts component tester and their capacitance tests were a joke.

Most of the old caps were merely snipped out leaving 1/4" long tails to aid the fitting of the new caps and also this ensured I din't lose the location. The new caps had insulation and coils added using my miniature coil winder; it was very easy and saved a lot of frustration to solder these in place after scraping the tails with a craft knife.

I found I could vary the whistle a great deal by rotating the Horizontal hold control.

At last after spending yet more time I found the 500mA fuse and it was as Dom guessed being one of the 2A fuses on the rear panel; I was determined to find it and it was a struggle gaining sight of the rear panel but when I did I found both fuses marked on the panel; one at 1.5A the other the elusive fuse marked at 500mA. For the time being I've left the 2A in place.

I had to go out this afternoon and have just returned so many thanks John for all the additional information which I've just printed off. After tea I'll see if I can produce some illuminations at the LOPT following your instructions.

I took voltage readings at both 30P4 and U191 after the cap change but still no raster on the screen;

U191; Pin 1 84V; Pin4 83V; Pin5 168V; Pin6 295V Pins 7 & 8 0V.

30P4; Pin1 84V; Pin2 0V; Pin4 120V; Pin5 -23V; Pin6 282V; Pin7 0V; Pin8 4V.

I've built up a stack of paperwork already and whilst looking through it earlier noticed charts with valve pin outs and voltages; I need to slow down a bit as there is a great deal to absorb; why aren't days longer?

The channel position selector knob has been extremely loose all the while I've owned this set well today it isn't loose any more as it finally broke off giving me another problem to resolve later..

Kind regards, Col.

13th Sep 2011, 5:14 pm	#103
Retired Heptode Join Date: Mar 2009 Location: Fenay Bridge, Huddersfield. UK. Posts: 673	Re: Restorers dream part 2 the chassis. Hi, Today started early; I was wide awake in bed at 5.15 this morning fighting the urge to get into the workshop. As caps play such an important role and this chassis was full of waxy caps I've spent the morning changing them rather than taking a lot of time trying to identify each one. Every cap I replaced was leaking badly on test. I used 630V units throughout with the exception of a Metalpack Visconol 0.02uF rated at 750V on a large transformer so I used a TCC Supermold 0.022 rated at 1500VDC. All the caps removed were leaking badly on the 100/200V range of the Hunts component tester and their capacitance tests were a joke. Most of the old caps were merely snipped out leaving 1/4" long tails to aid the fitting of the new caps and also this ensured I din't lose the location. The new caps had insulation and coils added using my miniature coil winder; it was very easy and saved a lot of frustration to solder these in place after scraping the tails with a craft knife. I found I could vary the whistle a great deal by rotating the Horizontal hold control. At last after spending yet more time I found the 500mA fuse and it was as Dom guessed being one of the 2A fuses on the rear panel; I was determined to find it and it was a struggle gaining sight of the rear panel but when I did I found both fuses marked on the panel; one at 1.5A the other the elusive fuse marked at 500mA. For the time being I've left the 2A in place. I had to go out this afternoon and have just returned so many thanks John for all the additional information which I've just printed off. After tea I'll see if I can produce some illuminations at the LOPT following your instructions. I took voltage readings at both 30P4 and U191 after the cap change but still no raster on the screen; U191; Pin 1 84V; Pin4 83V; Pin5 168V; Pin6 295V Pins 7 & 8 0V. 30P4; Pin1 84V; Pin2 0V; Pin4 120V; Pin5 -23V; Pin6 282V; Pin7 0V; Pin8 4V. I've built up a stack of paperwork already and whilst looking through it earlier noticed charts with valve pin outs and voltages; I need to slow down a bit as there is a great deal to absorb; why aren't days longer? The channel position selector knob has been extremely loose all the while I've owned this set well today it isn't loose any more as it finally broke off giving me another problem to resolve later.. Kind regards, Col. Attached Thumbnails