Bush A774

[EnyaFox]

They both look very familiar. I think the first one looks better cosmetically. I will need to swap the tuners over if I use the first cabinet. The tube, this new one has a long deepish scratch on it. I will hook my tester onto them at some point after a bit of playing around.

Another thing, can the DY802 be replaced with the DY86 or 87?

[EnyaFox]

Here's another photo of its current view.

[EnyaFox]

With higher wattage bulbs in my limiter, the TV seems to show a full picture and is working quite well.

[slidertogrid]

That looks good! I would say it is OK now to give it full mains, run it for a while and keep an eye on it. Then check the main capacitor can and the LOPT for any signs of heating above what would be normal. If the set still has its yellow or grey plastic TCC capacitors you are doing well as they are usually leaky to the point that they affect the frame lin etc. looks like you may have a set that has been stored in a dry environment.
As you probably know the chassis is easy to swap over into the other set if you want to see what the tube is like, better to picture test a mono tube than to trust a tester as the recent thread on the field find Sobell has demonstrated...

[its ur aerial]

Re. DY86/87/ Dy802, there is a difference, can't remember what: shrug: but back in the day we put in either, I believe the DY802 was the modern equivalent .
Running that set through your Lamp limiter, (and I understand why) may affect the supply to your set and thus the Heater and HT volts probably more than you might think and affecting its performance
A common obscure fault with these sets was, dry joints and cracks on the chassis were it is soldered to the earth print on the main PCB, this gives you weak sync and other weird faults .
Any way you have done very well, they were never a big favourite in the Trade.

[slidertogrid]

I think the DY802 was a higher rated valve for later sets with higher EHT so it will replace the DY86/87 . the 87 was just a later version of the 86 with better insulation I think... as a rule 86/87 for earlier 19" sets 802 for later 20/24" 'Square screen' sets.

[EnyaFox]

Originally Posted by slidertogrid

That looks good! I would say it is OK now to give it full mains, run it for a while and keep an eye on it. Then check the main capacitor can and the LOPT for any signs of heating above what would be normal. If the set still has its yellow or grey plastic TCC capacitors you are doing well as they are usually leaky to the point that they affect the frame lin etc. looks like you may have a set that has been stored in a dry environment.
As you probably know the chassis is easy to swap over into the other set if you want to see what the tube is like, better to picture test a mono tube than to trust a tester as the recent thread on the field find Sobell has demonstrated...

I had tried each tube, one kept ballooning but the one I prefer does not thankfully. I had been measuring the output voltage on the limiter with a multimeter, it sits around 220v.

[Hybrid tellies]

Glad it's come to life. Make sure you resolder all the earthing or chassis joints to the PCB. You can avoid a lot of problems doing this.
If the mains filter capacitor has been snipped out I would make sure you replace it as it can result in the on off switch contacts arcing over when you switch the set off.

[EnyaFox]

The mains filter capacitor was the first thing I changed. I will resolder all the chassis joints when I work on it next.

I have replaced most of the electrolytics and that has helped with all the stability issues I think.

What steps, if there's any, should I take that could possibly make the TV less likely to fail in the future?

[Welsh Anorak]

As Simon says get a big iron and resolder the earthing frame to the PCB at all the points. It may be necessary to remove the solder, clean and add flux, but it's worth the effort.
Also run the boost voltage as low as you can with acceptable width so the LOPT doesn't struggle too much.
Otherwise they were pretty reliable TVs let down by the LOPT. The picturess aren't bad compared with, say a Thorn 1500, but the previous A640/793 and later A816 did put them in the shade.

[flyingtech55]

Agree with the comments about resoldering the PCB 'earthing pads'. Some technicians used to wire them all together with insulated copper wire. Some made a better job of it than others it has to be said.


TimR

[its ur aerial]

This was my Modus operandi, for the more troublesome examples, and as neat as possible, given the circumstances, of the customers dwelling, many only lit by a 15W Pygmy lamp Ah, the memories of, Field service, wasn't it a joy! Wiping your feet on the way out
Ken, G6HZG.

[EnyaFox]

Originally Posted by Welsh Anorak

As Simon says get a big iron and resolder the earthing frame to the PCB at all the points. It may be necessary to remove the solder, clean and add flux, but it's worth the effort.
Also run the boost voltage as low as you can with acceptable width so the LOPT doesn't struggle too much.
Otherwise they were pretty reliable TVs let down by the LOPT. The pictures's aren't bad compared with, say a Thorn 1500, but the previous A640/793 and later A816 did put them in the shade.

Will continue on it tonight hopefully.

[flyingtech55]

....... Wiping your feet on the way out

Ken, G6HZG.

Oh yes...got that t-shirt. The ones you lifted but kept the set away from your body while you carried it out to the van 'cause you didn't want it to touch any part of you. Just your hands was bad enough!

TimR

[its ur aerial]

Tim.....Kept the set away from your body
Or sometimes, you didn't even want to touch the mains plug !! .
Ken G6HZG.

[Welsh Anorak]

Those days aren't over for some of us...