Cossor 927

[Techman]

I haven't been on to post for a while - been busy with work & radios, reading stuff on here, following the T62 thread etc. etc. Lots been happening - had smoke & sparks from an old RGD auto-tune, but the Pye P75 & the HMV 1125 are in constant use & working fine. Grundig 3028 needs a couple of valves - I'll have to start threads on some of these others soon!

So, back to the Cossor 927 table model TV from 1952. As far as I can see I don't think there is any mention of this model on this forum or anywhere else on the net except a description & early advert on this site:-

http://www.thevalvepage.com/tvmanu/cossor/cossor.htm

I bought this set for five shillings at a church jumble sale when I was a teenager with my paper round money. I had it in my bedroom & I remember constructing a wooden stand for it with a rack underneath for the HMV 1125 radio. I made the stand at pillow height & had it about three feet from the side of the bed so that I could lay in bed at night & watch TV....home made stand is now long gone!

I didn't take this set with me when I left home & it was shoved up in the loft sometime in the mid 70s where it has remained in the same loft untouched until this Saturday just gone when I retrieved it.

It had been partially covered, so it hadn't got too dirty. I have to admit that I didn't even remove the back to have a look inside & with the weather being quite warm lately, the set would have had a chance to air out in the warm loft. So I connected it to a variac & slowly wound the voltage up a bit at a time. By about 180 volts I could see valve heaters glowing through the vent holes in the back cover & hear a slight hum from the speaker. At the point that I could see a glowing fillament from something high up & mounted sideways on, I realised that the EY51/SU61 was being powered by the line transformer & things were looking good. Then, after winding the variac a bit more & fiddleing with the brightness control we had a raster. I only ran the set for a few more seconds before winding the variac back down to zero & switching off.

I left it to stew for a while in the off state to let its electrolytics reform a bit. I then got the camera with the intention of firing it up again & taking a photo of it working, but just as I got the variac to about 180 volts & the set started to come to life again, there was a click & the fuse blew in the connector block. Now I knew the original cotton covered rubber insulated mains lead was well rotten & I was hoping to get away with keeping it on the set for the time being, but after cutting it back several times thus clearing the short, it blew again over about 100 volts.....this was on Saturday afternoon.

On Sunday afternoon, I took the set ouside to give the inside a good blow out. It wasn't actually that dirty, probably because I would have given it the same sort of blow out about 40 years ago when I first got it, so all that 50s & 60s coal fire dust would have gone before the set was even 20 years old.

Below are some pictures, the first is on the Saturday after I couldn't get it working a second time due to the shorting mains lead. The next ones are the inside views after a clean. The last one is just now after I fitted a temporary replacement mains lead & powered it up on the variac again - I only ran it for about 30 seconds, just long enough to take a photo of the raster.

I found that the mains switch contacts have quite a few ohms resistance after I removed the old lead so I can't understand why they didn't burn out on Saturday, unless the act of me un-soldering the lead has affected it. Anyway, for now, I've tacked the mains lead on the other side of the switch until I sort out what's happening & also find a 'period' non-rotten flex. All the wiring inside the set is early plastic covered & in good condition...It's funny how they used plastic insulation that was obviously available at the time on the internal wiring, but used rubber & cotton on the flex. I suspect that 'flex' is the ultimate reason, as the plastic of the day perhaps wouldn't have been flexible enough for a mains lead, whereas rubber would be.

So let's hear the good & the bad about this model please, from those that remember them & serviced them - what to watch out for etc. I have a circuit, so I guess 'that capacitor' C60, plus various ones round the line output transformer? How unusual is this set these days (I've never come across another...I expect about ten people will now post to say they've got half a dozen kicking around in their back rooms)

This set really is in lovely condition. It looks as though it has most of its original cossor valves other than the HT rectifier & probably the frame o/p valve, also the EY51 - I may have fitted another (second hand) one at the time. All advice & info will be carefully noted down for when I decide what I'm going to do with it as regards restoration or just ornamental use - I'm not sure yet.

I've just found my old valve signal generator, so if that still works then I might try feeding a bit of modulated RF into the aerial socket at some stage & see if we can get some bars.....I don't think that's bad for a set that's not been swithced on for at least 35 years - pix below:-

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[AlanBeckett]

The attachments aren't working
Alan

[Techman]

Ah yes, I see they're not working. Sorry about that. They were working at first last night. I'll sort it out later today - work calls now.....

[Tazman1966]

Sounds intriguing so far. Looking forward to seeing the pics too.

[FERNSEH]

The Cossor 927 is the first of a series of TV sets from the company to employ a two chassis system of construction that is similar to the Bush TV22.
Easy set to get going. No special valves used, although the Mullard sourced valves have American style type numbers. For example 6BX6 = EF80, 21A6 = PL81, 6AB8 = ECL80.

A trade advertisment.

www.thevalvepage.com/dbase/cossor/adv/927.jpg

DFWB.

[Heatercathodeshort]

This was my school mates first television. His mum had very poor health and spent a long time in bed. She had the Cossor 927 in the bedroom, probably one of the first 'second' sets when they purchased a GEC BT1746 for the main room.
Cossor are not collectors trendy favourites but an incredible company that dated back to well before the start of radio. They are however very interesting to enthusiasts and ex television engineers. Very well made receivers and they made a lot of their own very good quality valves and tubes until around 1950. Nice to see a preserved one. Regards, John.

[Techman]

I'll have another go with the pictures here......

[Techman]

Hi All,

Yes, you can see the two chassis system now that I've got the pictures up at last.

I think they must have been quite a reliable set as the internals seem to be fairly original - even down to most of the Cossor valves. I don't remember having any trouble with it back in the day, other than a 'blooming' picture due to the SU61 EHT rec being low emission, hence the EY51 in its place.

I bored a very small hole in the back of the on/off switch & injected some switch lube in so as to bring down that contact resistance. I've fitted some 60s/70s flat brown plastic covered mains lead to it for now - it's rather a long length & seems a bit of a waste, but I'll not cut it shorter just yet as I may yet find a more period lead in usable condition.

I've had it running for a while longer this evening & got the valve signal generator struck up. The generator needs a good service as it's been out of action for at least over 20 years - bad selector switch contacts & dirty pot tracks, but I did get some output on vision & sound....so I think this set would still operate if fed with the appropriate signal. I'd forgotten the non-standard two pin aerial socket this set has - I used to run a band three converter box on it for ITV. This box would have had the two pin aerial plug for the back of the set - I've found one of the band three boxes, but it isn't the one that I used to use with the set as it doesn't have any plugs on it - unless I cut them off at some time.

[Heatercathodeshort]

That set is a worker! Test card C is just around the corner. I presume the loft it was stored in is lined with felt under the tiles. This makes a great deal of difference especially if there is some mild form of heating such as a brick flue from am open fire passing through it or central heating pipes. J.

[Techman]

Hi Heatercathodeshort (love your username, BTW)

Yes, this set was stored in a dry, felt lined loft in a house built in 1967 - the house was probably only about six or so years old when the set went into its loft. So this set has always been in dry conditions - unlike a lot of my other old stuff which has moved around with me & spent a good bit of time in the attic room of a damp, woodworm infested old house on the Lincolnshire fens.

I haven't actually done any more with this set since I last posted (boring, I know) other than to give the cabinet a polish & it's actually now on display in the main room with a potted plant stood on top of it (on a protective mat, of course)

So I think we can safely say from what's been said so far, is that this set is very rare (could be the only survivor left - no one's said they know of another)...It's a very plain looking set, so not very interesting for collectors - (& I would agree with that...unlike a pretty little Vidor with the opening flap/door below the screen & two tone wood that I've got buried somewhere in the loft). As said, this Cossor is a very well made set & it certainly was reliable - I don't remember anything going wrong with it other than the low emission EHT rectifier...but as said by someone on another thread somewhere - having nothing other than the screen on the front of the cabinet is less distracting for the viewing experience.

I expect I will be coming back to this set again & powering it up & perhaps replace some 'likely' components at some stage, but at the moment I've been too busy playing with amplifiers, (another thread soon), sorting through all my old valves & components & reading everybody elses threads.

Any more comments on the Cossor are most welcome

Cheers

[The teleman]

Hi Techman , nice set , I have one of these sets sadly the crt has seen better days ,still quite a rare set your is the only other example that i know of . Cheers chris..

[neil29]

I used to have a 930 console. nice set until the woodworm got it . anyway good luck with your 927 . cheers neil.

[petertheorgan]

Its good to hear cossor televisions talked about , I have had for several years a cossor 918 tv/ radio console which worked but the frame linearity was not good , well last Saturday I had the chassis out and did all the caps in the frame circuit and the picture is perfect , the tube is like new!
Radio works well , I am just left with some hum on the TV sound

photos below

Peter

[chipp1968]

Peter thats a smashing set. Is the radio fixed in that position or does it fold down?

[petertheorgan]

the radio folds down into the top of the cabinet , on the front of the television is on/off vol . tone and contrast ,

on the radio section there is a 4 position switch on the left TV SW MW LW and the tuning knob is on the right ..

When on TV , radio dial lights are extinguished and when on radio , tv valves and tube heaters are extinguished

super picture too

cheers

peter

[chipp1968]

Very nice Peter .
I hope Techman can get his up and running soon too.