Anyone recognise this Spencer West TV set

[Kat Manton]

Hi,

What a wonderful set, admittedly for all the wrong reasons. I think I want one, along with anything else mentioned in the Most dreadful 405-line tv thread, naturally... (Not yet, I have too many projects!)

It is vital that sets such as this are preserved otherwise future generations won't realise the manufacturers of the past managed to screw things up on occasion. Or something. Anyway, the 'oddballs' can be a lot of fun!

I love the early 'surface mount' PCBs, what goes around, comes around...

Cheers, Kat

[jay_oldstuff]

Did a little more tonight, swaped the two GEX32 diodes for OA90's that has broght the test tone back in nice and undistorted but the picture is unchanged Ie there and locked but with ripple also if i turn the test tone off on the arora there is a hum from the speaker, first thing i tryed was subing the duel rez/smothing can with a coupple of modern caps tacked to the pcb but no change, getting a little tired now so gonna give it a rest till tomorrow. then probebly go through the other electrolitics in the set, i'm sure it's a smoothing issue.

Jay

[Steve_P]

Other caps on the HT line, the LT Line (Valve Heaters) or possibly a H-K short in a valve.

Cheers,

Steve P.

[jay_oldstuff]

yea Steve once i've had a look at those last remaining electrolytics I think it's valve subbing time, so far i have not had to take the chassis out the set but i will have to to tackle those last caps while it's out i think i'll give everything a good clean test all valves clean all valve pins and sockets, it's not far off but i want this set showing a good picture.

Jay

[jay_oldstuff]

Hi chaps I'm still at it with this set, the last two remaining electrolytics changed and the hum from the speaker with no signal input is gone, unfortunately no difference on picture with the aurora connected the ripple is still there, so thinking Hmm like steve suggested HK short maybe? so went through all valves on the good old mullard high speed valve tester. No HK shorts where found and all valves that showed any slight leaks i swapped for known good valves from my stock. picture still the same. so could i be looking at a HK short in the crt. i might try running thre crt heater from my bench supply. anyone know the heater voltage on a Brimar C17LM. or any onther ideas this set is starting to live up to it's reputation.
Jay

[oldticktock]

Hi Jay,

My data book states 6.3V/0.3A for the heater

18KV final Anode, 0.5 first Anode

Chris

[Sideband]

Too much signal from the Aurora? Just a thought that it may be signal overload.



SB

[jay_oldstuff]

I've allready tryed an attenuator also tryed turning down the sensitivity controle on the rear of the set.

thanks OTT. so may try 6.3V from an old valve TX.

Jay

[oldticktock]

Post a picture of the Testcard or is it still the same as post #37

[jay_oldstuff]

It's no longer a little squashed, fills the screen nicely it's just the verticals are jagged.
i'll try to get a pic up but i've left my SLR at work and my compact struggles with tacking pics of tv screens.

Jay

[jay_oldstuff]

Well i got an hours play time today so unsoldered the heater wireing from the crt joined them together to maintain heater continuity. then fed the crt's heater from my bench supply. just the same stable picture but with ragged verticals, I deas anyone?

Jay

[oldticktock]

Looking through my books I found these 3, are they anything like your testcard? longshot I know.

[Heatercathodeshort]

I presume you have replaced our old friend the sync coupling capacitor. Failing this it looks as if the set is off tune. Set the fine tuner mid way and adjust the oscillator coil core with an insulated non metalic tool with a small screwdriver shaped end. We used to use plastic knitting needles in the 60's suitably filed down. If the tuning is odd it is possible that the I.F. alignment has been tampered with in the hope that it might mask other faults. This was very common with older 'past it' repair guys of the past. J.

[jay_oldstuff]

Hi OTT just like the third picture.
hi John sync coupling cap replaced, Hmm now where's mothers knitting needles.

Jay

[oldticktock]

Just in case your interested the 3rd picture fault is described as follows:-

This fault occurs because of a faulty separation of the sync pulses from the composite video signal. When a line ends in peak white, the line timebase triggers early before the 1.5usec interval and the following line is displaced to the left. This displacement occurs because the line oscillator is triggered by the trailing edge of the video signal corresponding to a white part of the picture. Thus a series of lines ending in white will be displaced to the left of the picture as seen in pic 3. It is usually the result of insufficient bias on the sync separator valve. They talk about increasing the value of either the grid leak resistor or the screen feed resistor. The sync sparator valve should be inspected, perhaps sub it and check for poor grid insulation.

[Heatercathodeshort]

The tuner looks like a Cyldon from your pics. Remove channel selector and fine tuner knobs and you will see access to the oscillator biscuit that is selected i.e. channel 1. Insert the plastic knitting needle [end shaped to tapered screwdriver] and taking VERY great care locate the end in the coil slug and give it a turn either way and monitor the effect. Use a torch to locate the small hole around 3/4 inch from the turret spindle. Do not force anything. Only the slightest forward pressure is required to locate the slug.
The tuning looks well off from your pic. J.

[jay_oldstuff]

What can i say John your a genious. filed down an old knitting needle gave the oscillator coil a tweek and bingo jagged verticales gone, as you can see from the test card it needs a little further tweeking but it's almost there now.

big thanks John i would of still been chaseing my tail.

Jay

[Heatercathodeshort]

Great news! Picture looks very good and is probably better than when the set was new...
Great oddball set and nice to see it up and working. J.

[Sideband]

Eeee! That's cracking is that!!

A very good picture has been achieved. What's the rest of it like? I think the sound output was an ECC82? Any good?



SB

[jay_oldstuff]

Think it is an ECL80 for the audio output, I would describe it as adequate for an average size room.
There is still quite a bit to do on the set the controles are all a bit tuchy (need a clean) the picture needs seting up properly on the test card,
the caps i've used are orange dip's (all the correct value) and i've just tacked them in for testing so plenty still to do,
To be honnest i'm not sure what i am going to do with this set i'm more into band 1 only sets, so it may end up in the sets offered section before very long.

Jay