Philco BT1410 - Television which looks like a radio.

[em536716]

Recently bought this lovely odd looking Philco off eBay.

It came to be all original and in fair condition and looks... well weird!

The Mazda CRT in it is soft as all hell, but gives an acceptable picture.

So far I’ve done a first light. RF, sync and timebases all seemed to work to an extent.

Some work had been done on improving the frame timebase’s linearity, and make the line timebase a little more reliable. Cleaning of the rear slider controls was necessary to unstick them from their frozen state and the original finned diode has been replaced with a Russian diode as the original would go high resistance after running for sometime. A current limiting resistor was installed too.

Jobs to do now is replace the EHT capacitor, clean through the chassis and valve bases, and case. Then finally go through the vision and sound stages. Filled with those .003/.002 TCC capacitors which go completely short circuit.

I’ve attached a photo of the set working and a link to a little video I made. It’s quite boring - I talk on a bit. Anyway, here’s some photos!

A link to the video https://youtu.be/ktET7v4thAM

[em536716]

Also the HT cap in it wasn’t very happy either... I’ve never seen a TV which uses a field coil speaker. Would’ve been the only thing doing filtering during the first light!

[em536716]

Also the HT cap in it wasn’t very happy either... I’ve never seen a TV which uses a field coil speaker. Would’ve been the only thing doing filtering during the first light!

[German Dalek]

Heck, that set is still on my wish list!!!!!!!!!!!!!!!
It looks upside down, I love it!
Folks, it is Christmas time!
May I can place here my adress?

I shall keep a space for it under my Christmas tree!

Regards,
German Dalek

[Jac]

This looks like the standard Plessey chassis, as in the Defiant TR949.

Nice looking set!

Jac

[German Dalek]

Just my thoughts!
Was it really ever sold under the Philco brand?

Regards,
German Dalek

[em536716]

Originally Posted by German Dalek

Heck, that set is still on my wish list!!!!!!!!!!!!!!!
It looks upside down, I love it!
Folks, it is Christmas time!
May I can place here my adress?

I shall keep a space for it under my Christmas tree!

Regards,
German Dalek

Sorry German Dalek but it’s safe well under my christmas tree for the time being

[em536716]

Originally Posted by Jac

This looks like the standard Plessey chassis, as in the Defiant TR949.

Nice looking set!

Jac

That’s absolutely right Jac.

It’s a very nice set, and the cabinet has come up very well with some polishing!

Performance is probably on par with similarly cheap built sets from the time. Saying that, I can’t really compare it with any other of the 405 sets I have as it wouldn’t be fair. The tube is soft so the picture isn’t as brilliant as it probably once was!

[em536716]

Righto everyone his the finished product of the chassis!

The remaining caps in the RF stages were changed and resistors throughout checked. I’m surprised to say all are within 10 percent tolerance and the set performs well.

It did send me the runaround a couple times. I accidentally unsoldered the coupling to the cathode so no video was going to the tube. Concerned I shorted between grid and cathode and was able to get a raster of sorts. I checked the volts from the brightness pot and this appeared to vary as I adjusted the control... then I realised the mistake I made! Fewwww!!!

The set has been running continuously for the past 4 hours and is rock solid on the bench. I have cleaned the cabinet and polished as well. It’s very shiny and will include a proper picture of the cab when I reinstall the chassis tomorrow.

The set performs reasonable with near to uniform focus across the tube. An added smoothing EHT cap has helped with this but as the tube is so weak, adjusting the brightness or contrast control blows out the image.

Anyway, here’s a couple snaps of it out of the cab and working well.

[em536716]

And here’s a photo of the set producing a picture. Some interference going on in the workshop tonight.

I will need to clean the valve bases to ensure good connection too.

Is it worth doing an alignment on it?

[German Dalek]

Yes, it is worth to get a new alignment after so many years!
What about another CRT?
Philips or or one from an Ekco?
The set performs like a daily driver, so I should do that!
You have invested money and time and the answer is a clean result.
It is too good, to use it only 4 times a year with a (little bit) weak picture.

Regards,
German Dalek

[Heatercathodeshort]

Under no circumstances attempt a realignment of the .I.F deck. It is a Plessey MK1 chassis and very stable unless someone has fiddled the I.F.'s which is unlikely.
Check the setting of the local oscillator and the type of decoupling capacitors used in the strip. Ceramic and silver micas should be ok. I played with many of these when I was a kid 60 years ago. Never had a twiddled one! Good luck with it. John.

[Freya]

Hi Ed,
I have the Defiant branded version of this, my first impression was the cabinet was made for a twelve inch tube. Something is not right with yours still, the signal should be crystal clear albeit with the low output CRM92.
It was quite a long time ago when mine was restored but the Plessey chassis did throw up some different challenges other than the usual blanket capacitor changing.

[em536716]

Thanks for the feedback everyone.

Re smearing patterned video, I believe this is just interference caused by using clip leads from the standards converter to the set - however I will investigate this when I next go in the workshop (won’t be until Friday now!)

As mentioned to Forum user Freya in a PM, the photo I uploaded of the set running had unsmoothed EHT. Accidentally uploaded the wrong pics. Whilst this would account for a wonky picture without good focus, it doesn’t account for the weird patterning which I can see is noticeable - but I believe this is a fault of the cable I used to the standards converter not being shielded and lots of power supplies around me however I will investigate this and see if this is an issue when I’m back as well as finish up and upload a few snaps of the chassis and cab. It’s looking very good though and I’m very happy with how things are ATM.


Thanks for your advice John, I think I’ll stay clear of tweaking any cores then - but will check those micas in IF to see if any are faulty. I doubt it though.

[em536716]

Originally Posted by Freya

Hi Ed,
I have the Defiant branded version of this, my first impression was the cabinet was made for a twelve inch tube. Something is not right with yours still, the signal should be crystal clear albeit with the low output CRM92.
It was quite a long time ago when mine was restored but the Plessey chassis did throw up some different challenges other than the usual blanket capacitor changing.

I think I was very lucky that I’ve got an untouched set, that really did work on the first power up - which is unbelievable.

I don’t think much else can go wrong in there other than a slider control failing after use - maybe a low emission valve but I doubt it.

I’ll post a proper update when I’m back down there again

[dragonser]

Hi,
I wonder if the patterning could be too much signal from the Standards Converter ?
Of course it may not be that simple at all.
what a nice unusual set ?

[em536716]

Originally Posted by dragonser

Hi,
I wonder if the patterning could be too much signal from the Standards Converter ?
Of course it may not be that simple at all.
what a nice unusual set ?

This is a very good point I haven’t considered. I have a few attenuators which I can use to test this theory

[em536716]

After taking some advice left on the forum I have checked the Vision side of things and haven’t found anything out of place. All the mica caps within the set check near spot on, I have cleaned all valve bases and even fed video directly into the Video OP valve. Appears to be more definition when going straight into the video valve but not so much so that it really improves watching the set.

I’ve decided not to bother with touching the alignment as this probably won’t make much improvement. The patterning is actually noise from the power supply for the standards converter which is very close by!!!

Focus is better but not perfect. You’ll notice the top right of the image seems to degrade but adjusting the centring screws seems to either ghost one side of the picture whilst de focusing another. Rotating the tube doesn’t improve this. When watching video I can’t really notice this tbh!

Anyway, here’s a few final shots of the set running before it goes back in the cab tonight.

[em536716]

Just a note about these photos. They appear to be lower quality when I upload them onto the thread, I think this is because I’m uploading them straight from my phone.

Tonight I’ll finish off the “part 2” video on my YouTube channel and post here

[em536716]

Final update.

The set is now back in its cabinet and all done and happy.

Sadly the tube developed a grid cathode short which I was able to clear. Annoyingly the emission on the tube has decreased a lot too.

Otherwise the set performs quite well. Thanks to peter sanders for providing me with a new EHT cap which I restuffed inside then old one on the chassis.

There’s some photos along with the part 2 of my restoration.

The cabinet looks fab!