Another TV from the very excellent Chris "Crustytv"
It was originally thought that this was a 1966 model but I've found a manufacturing date of 1968 inside.
Beautifully constructed with a hefty metal frame! I suppose the concept of a "portable TV" back then meant being rugged enough to actually be hauled around. The first thing I notice is the fuse for 12 volt operation is popped. There's no obvious reason for this but the general good condition of the set makes me wonder if the fuse blew and it was just stored away and forgotten about. If someone tried to operate it via a very flat 12 volt battery the set may have tried to draw more current and popped the fuse.
The major issue to address is the risk of these sets is the regulator exceeding 11 volts and blowing up the heater, so first power up will be with the tube neck board disconnected. I'm also going to be using this on 12 volts using an Xbox 360 games console power supply.
I can hear the hiss from the speaker and the 405 line whistle when 405 is selected (much to the annoyance of my 14 year old who already hates the high-pitched whine from CRT TVs!) The heaters are getting a fairly stable 11.03 volts, but I don't trust it! I'm going to isolate the heaters from the rest of the TV using a modern regulated supply. I like these as they clearly display the voltage.
I really don't like cutting through the tracks on the PCB of such an original and good condition TV, but needs must.
We have a raster! There's clearly issues and I can't 100% tell if there's IF problems at this stage but today's goal was to at least make the set safe enough to use without blowing up the heater in the CRT. That's enough for today!
Hooked up my Atari 2600 as my RF modulator seems to have thrown a fit. The lack of full raster and snow was just down to the horizontal and vertical hold being off. The sound carrier is slightly off as I can only hear the sound when I detune away from the Atari's signal. The picture needs centering but hey, we got a picture!
Did some centering on the picture and it's looking really good!
Have to say this isn't the easiest set to work on and it has a few "quirks" but I think this all adds to its charm. Not going to replace any capacitors or anything unless it absolutely needs it.
I also have a TVette and it's 405 performance is excellent, 625 needs a little attention. I thought I was going to have to make it single standard only, the system switch had a nasty burnup on the scan coil switching contacts, Thankfully fellow member Malc Scott donated a unit with an o/c CRT heater which helped me out, still got some bits and bobs of it if you need anything.
Today the living room started to fill with the smell of burning electronics! Nothing obvious on the rear timebase panel (of course it wouldn't be that easy!) and after lifting a couple of capacitors to check, everything seems fine with that. Time to remove the huge IF panel that's fitted underneath.
AHA!
A somewhat charred metal oxide diode but according to the schematics it's supposed to be two AA129 Germanium diodes:
I'm guessing this was a later factory revision as it certainly doesn't look like it's been replaced.
Been chatting with my Father in-law and he recommends a 10 ohm 5 watt resistor in series if I go the modern diode route.
A somewhat charred metal oxide diode but according to the schematics it's supposed to be two AA129 Germanium diodes:
Wayne, I think you'll find that is an NTC VDR (BRN/ORG/BRN), not a diode. It is factory fitted, it replaced the two diodes X2020/X2021. It's R2140 and the VDR type is an E201BC/P130E.
p.s.
I'm sure you've worked it out, but the value is 130R
/Admin Hat on
Whilst I'm happy to let threads drift a little, there are already 7 posts not relevant to the T-Vette, that's almost half the thread. For the most part there is very little need to moderate at Vrat, members self moderate, but occasionally we do need to step in. This is one of those occasions. I think we should refrain from steering Wayne's thread off any further into computer IC chips for vintage consoles, after all, this is the B&W TV section. I'm happy for the conversation to take place in the vintage computers & consoles section, and therefore split it off the unrelated posts. Please refrain for further Vintage console, off-topic discussions, in this thread.
@crustytv AHA! Thanks Chris, I'd never seen one like that. Doesn't help that it was the charred remains, I managed to find what's left of the markings in the case of the T-vette.
I think I'm just going to put this set back together and let it sit on the shelf for a bit. I'm also going to redraw this from the service manual:
My Covid brain won't allow me to comprehend the wiring so I think redrawing this in colour will be a far better plan when my brain is semi-working again.
If you seek out my 48 page, 960-post thread (yep, and it's still not finished) on my Philips G6 restoration, you'll see me being equally traumatised by a Philips.
Philips to my mind seemed hell-bent on complexity of design, awful schematics and scant regard for how some of their TV's could be serviced by an engineer out in the field. As I think I remarked fairly often in that G6 thread, I would never have wanted to come across one in the field for repairs.
@crustytv in one of my previous lives I used to rewire classic cars. I used to redraw the wiring loom first in full colour then take on the rewire, so I'm thinking this is the best way to go about it.
Gotta live the rats nest wiring diagram, drawn by a drunken spider that fell in some ink! I’ve put my T-vette to one side too, mostly because new projects arrived, but also because no matter what I did I couldn’t get anywhere with the damn sync fault, if it even is a fault! I may revisit it when I’ve finished playing with that HP scope 🙂
@lloyd I think I know the reason behind the rats nest wiring diagram and indeed the general working practices behind Philips at the time. It was "because Ted said" - pretty much any British factory has a Ted, the guy who's been there many years and nobody seems to know how he got the authority to implement the random stuff that he does and none of it makes sense but we have to go with it "because Ted said" as apparently he's an expert...
Why can't I use a ruler and write the colours of the wires on this wiring diagram? Because Ted said.
Why can't we have a nice neat wiring loom that is simply plugged into each board? Surely that would save time and money? Because Ted said.
Virtually any British-manufactured product will have evidence of Ted. Was taking my Brother in-law's Jaguar X-Type for an MOT, I kept spotting random things like a slide switch in the steering wheel which looked more like it came from some Poundland Christmas lights... why can't we use a nice quality switch here? Because Ted said!
Just goes to show that a lot of opinions depend on experience with different manufacturers. I spent 40 years at Philips in several roles and found their circuit diagrams easy to read compared to some other manufacturers. I do agree on complexity and thought that some of their products were 'over engineered'. However when parts, technical advice and manufacturer training was available, a lot of the problems experienced now just didn't exist. Plus of course, the sets were current and reasonably clean and new to work on.
It's interesting to hear other people's comments on Philips because I find Thorn colour TV circuits quite odd. Salora circuits can be a bit daunting as well.
The USA style of circuit drawing I found harder to follow, it was just unfamiliarity with the style. I didn’t see many USA products but with the influx of Japanese sets I got used to their similar style. During the 60’s and early 70’s service manuals usually contained at least brief, sometimes in depth circuit descriptions, I found these invaluable coupled with the theory I learned at Tech college.
Repairing the sets had to be in the main, quick and reliable to make a profit, so being familiar with the circuit and the set made a big difference. I feel that some of the negativity felt by repairers for some makes was very often down to unfamiliarity. Of course every maker seemed to produce a lemon at some time.
I didn’t particularly like fixing Thorn CTV’s but I didn’t see enough of them to gain any experience so everyone was a voyage of discovery and service information was scarce for me. The BW sets although I saw few were easy to fix.
The Philips circuits were ok, no worse or better than others, every maker had their style.
@sideband I didn't mean to cause offense or anything. I suppose when you're used to drawings done in a particular style or you understand the logic behind why something is done a certain way it makes sense to you. I certainly wouldn't expect someone to understand the drawings I use at work without training and experience with these exact drawings.
As an outsider, I'm seriously struggling with this drawing though, there's not even any mention of the colours of the wires:
No Offence taken!! I was just being matter-of-fact. I know a lot of people who don't like Philips circuits and probably an equal number who think they are the best thing since sliced bread! My late brother worked for Radio Rentals for about 20 years and thought the Thorn circuits were the best and easiest to understand. I always though they were a bit weird and when SYCLOPS came along well.....he was welcome to it of course. In fact Salora used a similar type of circuit but called it IPSALO. I think Grundig also did something similar but it might not have been a Grundig design. I repaired all of these in the past but still thought they were weird!
It's just what you grow up with or are trained on. I've worked on most brands during my 40 years in the Trade but always felt at home with Philips since that is where I spent most of that time.
@sideband I didn't mean to cause offense or anything. I suppose when you're used to drawings done in a particular style or you understand the logic behind why something is done a certain way it makes sense to you. I certainly wouldn't expect someone to understand the drawings I use at work without training and experience with these exact drawings.
As an outsider, I'm seriously struggling with this drawing though, there's not even any mention of the colours of the wires:
Those wiring diagrams are a nightmare. Much easier to follow the circuit diagram!
