Pye Red Box - UK Vintage Radio Repair and Restoration Discussion Forum

Studio263 · 7th Jul 2018, 9:54 pm

This set was offered on a free / collection only basis on the forum recently. They were a nice model; I’ve always liked the Philips version (1120) but the Pye, with its painted red finish, is the most distinctive. Since no one else wanted it and it seemed a shame to let it go to waste I thought I’d better give it a go.

They date back to the 1985 season and so were made at the same time as the CTX, KT4 and K40 chassis. The Philips 1120 and the Pye Red Box were not made by Philips though, they came from DS Loewe in Germany instead. The chassis has many similarities to the later Philips CP90 but is smaller, ideal for this very compact (10”) set. With minor modifications the chassis could drive 14” and 16” (90 Deg.) tubes as well, but I don’t think Philips ever used it for these screen sizes. I’ve also seen full sized Loewe sets with similar chassis in them, but no doubt there are many differences at this scale.

These sets sometimes get confused with another small Philips model of the era, the 'Tube Cube'. This was a proper Philips design however, and combines a 10" monochrome TV, a cassette recorder, an AM/FM radio and a digital clock into one amazingly compact package. I'm sure there was a Pye version of it too but I can't remember that that was called.

A 12V battery convertor is part of the standard specification. This is located on a sub panel at the side of the cabinet and injects power straight into the set’s HT rail. They also have a SCART connector, fully equipped with carefully engineered analogue RGB inputs. These sets look like they should have remote control but they don’t – operation is manual only. Frequency synthesis tuning is used so channel numbers can be entered directly.

We had a few of these pass through the shop when I was there, including the ‘proper’ Loewe version which had been bought through Harrods and was very stylish. The owner was an architect and turned up in a Citroen CX turbo, clearly a man of considerable taste (and means!). I don’t remember any major catastrophes with the chassis, the main concern being the electrolytic capacitors used in some of them leaking on to the board and rotting the trackwork on the component side away. The mains switch wasn’t great either; its the same rubbish half black / half white sort that got Sony into trouble and soon gets sticky or refuses to latch. Issues with the line output transformer and the microcontroller IC have also been reported but I’ve not had any problems with either. This set has a Plessey LOPT (original) which I don’t think I’ve seen in a Philips colour set before and the micro is on an adaptor base, so maybe improvements had already been put in place by the time this one was made.

A pleasant run out on the evening of the summer solstice saw the set collected, the owner said that he had stopped using it after only a few years and the excellent, unmarked condition of the cabinet bears this out. Never the less, a first class picture appeared as soon as the set was switched on, the only complaint being a sepia hue to the greyscale. This was another reasonably common weakness of the design – grey scale drift due to the pre-set controls on the tube base panel changing value. This time though a dose of cleaner and a good working to and fro a few times seemed to sort it – its the type of control with the orange plastic screwdriver slot in the middle (which this set doesn’t have) that one has to change. Distorted sound was also noted. The upward facing loudspeaker was full of dust but cleaning it out only provided a partial cure. The faulty component turned out to be the loudspeaker socket. This is an unusual DIN type with one central blade and a round pin hole on either side so that a normal DIN loudspeaker plug can be inserted either way round. Each pin hole has a switch behind it and in the Loewe circuit the loudspeaker current passes through both in series. Both showed a non-zero resistance so out came the socket. It is a high quality component and cleaning is possible, doing this got the sound working nicely again.

Knowing of the leaking capacitor / ruined PCB issue I took a few out to have a look. Luckily, all were clean, dry and read as new, so back in there they went. This may not be a Philips chassis but there are plenty of Philips components in it, which as we know are very durable. The power supply is TDA4600 based, probably the best package of the era. No problems seemed to be brewing up there either. Using either UHF, CVBS or RGB inputs the performance is first rate. RGB in particular gives near monitor levels of performance, the only limiting factors being the stripe pitch of the tube and the slight horizontal overscan – these sets don’t have an EW modulator (72 Deg. D
deflection means the tube is self-correcting) so this can’t be adjusted.

Does anyone else have any experience of these?

linescan87 · 7th Jul 2018, 10:10 pm

I have one of these little sets in storage, good little performers. Never had the back off.

John Joe.

Sideband · 7th Jul 2018, 10:49 pm

Yes....serviced quite a few of these when at Philips. If yours has the 'piggyback' microcontroller, its the early version. Later versions did away with the adaptor and everything was contained in one chip. There were a few problems with plated through connections resulting in 88 appearing in the display. The RGB pots were a common failing.

I did a service article for these in 'Television' but can't remember the actual issue....I'll see if I can find it.

Heatercathodeshort · 7th Jul 2018, 10:51 pm

The only problem I had with these was a dead set symptom with '88' in the display. Very intermittent and due to dry joints through the layered print. John.

Snap! J.

Sideband · 7th Jul 2018, 11:00 pm

Quote:

Originally Posted by Sideband

I did a service article for these in 'Television' but can't remember the actual issue....I'll see if I can find it.

Found it....January 1995. If you don't have a copy look here

Studio263 · 9th Jul 2018, 1:04 pm

I knew it couldn't last...

Watching the set over the weekend I noticed that every minute or so the width would drop, the height would increase and the overall brightness level would fall. A few seconds later things would return to normal, then the process repeated itself.

A change in the HT voltage would do all these things, but why? A look at the chassis showed the answer. The 'set HT' control was that horrid type with the orange middle. Out it came and in went a new 4k7 preset. Things were fine after that, I set the main HT rail to 27V with a normal picture displayed.

While I was there, I noticed that the start up circuit uses a tiny thermistor in a little plastic box. I'd forgotten all about those, I think the Hitachi had them too. We used to get through quite a few, I suspect that the circuit would have to be modified if it failed now. As it was the soldering underneath it was a bit suspect, so I ran the iron over that too.

Jac · 9th Jul 2018, 2:40 pm

I have a Philips version still in the workshop to check video signals.
I had to resolder the vert deflection IC and the connections to the deflection unit.

Picture is acceptable, sound is nothing to write home about.
But it takes little space and has proved worthwile for testing.

Jac

Lloyd 1985 · 9th Jul 2018, 7:01 pm

I’ve got 2 of the Philips variants of these, one in the dark grey finish with a thin red stripe under the screen, and a white one. The white one has an odd fault, which I think could be the micro, it comes on with full volume and brightness, also sometimes no colour, and it’s not adjustable with the front controls. The colour slowly fades in after a while though!

The grey one works fine, despite being in awful condition! It survived being posted to me, the seller didn’t pack it in anything, just gaffer taped Jiffy bags over the front and back... it is missing it’s plastic screen cover, and the speaker is knackered. One day I might go and retrieve it from my storage unit and see if it still works!

Regards
Lloyd

Sideband · 9th Jul 2018, 9:18 pm

Quote:

Originally Posted by Lloyd 1985

I’ve got 2 of the Philips variants of these, one in the dark grey finish with a thin red stripe under the screen, and a white one. The white one has an odd fault, which I think could be the micro, it comes on with full volume and brightness, also sometimes no colour, and it’s not adjustable with the front controls. The colour slowly fades in after a while though!
Lloyd

Check out the article in post #5. The white ones were usually supplied as part of a viewdata kit.

Studio263 · 28th Aug 2018, 1:02 pm

Another, rather rougher example of this set has now appeared here. It's a Philips one this time, dark grey. There were endless faults to begin with but many resolved to iffy preset potentiometers, a bit of a bugbear in this model.

This left an odd one-line frame jitter which was only really objectionable on certain scenes but always there if you looked. Dropping the height stopped it, which turned out to be the clue.

In these sets, the line and frame stages both run from a +27V line from the power supply. This is smoothed by two 1000uF electrolytics, which are of the later blue Philips type. One read 930uF on the meter, the other about 950uF. Changing both cleared the fault, the frame stage must have been putting ripple back on the line when under full load. The originals are 50V rated but I don't keep those. Instead, I used some 35V Matsushita ones (M series) which are much easier to come by. The frame coil coupling capacitor was the same type and just as duff, so I changed that one too.

7th Jul 2018, 9:54 pm	#1
Studio263 Octode Join Date: Apr 2007 Location: Hampshire, UK. Posts: 1,576	Pye Red Box This set was offered on a free / collection only basis on the forum recently. They were a nice model; I’ve always liked the Philips version (1120) but the Pye, with its painted red finish, is the most distinctive. Since no one else wanted it and it seemed a shame to let it go to waste I thought I’d better give it a go. They date back to the 1985 season and so were made at the same time as the CTX, KT4 and K40 chassis. The Philips 1120 and the Pye Red Box were not made by Philips though, they came from DS Loewe in Germany instead. The chassis has many similarities to the later Philips CP90 but is smaller, ideal for this very compact (10”) set. With minor modifications the chassis could drive 14” and 16” (90 Deg.) tubes as well, but I don’t think Philips ever used it for these screen sizes. I’ve also seen full sized Loewe sets with similar chassis in them, but no doubt there are many differences at this scale. These sets sometimes get confused with another small Philips model of the era, the 'Tube Cube'. This was a proper Philips design however, and combines a 10" monochrome TV, a cassette recorder, an AM/FM radio and a digital clock into one amazingly compact package. I'm sure there was a Pye version of it too but I can't remember that that was called. A 12V battery convertor is part of the standard specification. This is located on a sub panel at the side of the cabinet and injects power straight into the set’s HT rail. They also have a SCART connector, fully equipped with carefully engineered analogue RGB inputs. These sets look like they should have remote control but they don’t – operation is manual only. Frequency synthesis tuning is used so channel numbers can be entered directly. We had a few of these pass through the shop when I was there, including the ‘proper’ Loewe version which had been bought through Harrods and was very stylish. The owner was an architect and turned up in a Citroen CX turbo, clearly a man of considerable taste (and means!). I don’t remember any major catastrophes with the chassis, the main concern being the electrolytic capacitors used in some of them leaking on to the board and rotting the trackwork on the component side away. The mains switch wasn’t great either; its the same rubbish half black / half white sort that got Sony into trouble and soon gets sticky or refuses to latch. Issues with the line output transformer and the microcontroller IC have also been reported but I’ve not had any problems with either. This set has a Plessey LOPT (original) which I don’t think I’ve seen in a Philips colour set before and the micro is on an adaptor base, so maybe improvements had already been put in place by the time this one was made. A pleasant run out on the evening of the summer solstice saw the set collected, the owner said that he had stopped using it after only a few years and the excellent, unmarked condition of the cabinet bears this out. Never the less, a first class picture appeared as soon as the set was switched on, the only complaint being a sepia hue to the greyscale. This was another reasonably common weakness of the design – grey scale drift due to the pre-set controls on the tube base panel changing value. This time though a dose of cleaner and a good working to and fro a few times seemed to sort it – its the type of control with the orange plastic screwdriver slot in the middle (which this set doesn’t have) that one has to change. Distorted sound was also noted. The upward facing loudspeaker was full of dust but cleaning it out only provided a partial cure. The faulty component turned out to be the loudspeaker socket. This is an unusual DIN type with one central blade and a round pin hole on either side so that a normal DIN loudspeaker plug can be inserted either way round. Each pin hole has a switch behind it and in the Loewe circuit the loudspeaker current passes through both in series. Both showed a non-zero resistance so out came the socket. It is a high quality component and cleaning is possible, doing this got the sound working nicely again. Knowing of the leaking capacitor / ruined PCB issue I took a few out to have a look. Luckily, all were clean, dry and read as new, so back in there they went. This may not be a Philips chassis but there are plenty of Philips components in it, which as we know are very durable. The power supply is TDA4600 based, probably the best package of the era. No problems seemed to be brewing up there either. Using either UHF, CVBS or RGB inputs the performance is first rate. RGB in particular gives near monitor levels of performance, the only limiting factors being the stripe pitch of the tube and the slight horizontal overscan – these sets don’t have an EW modulator (72 Deg. D deflection means the tube is self-correcting) so this can’t be adjusted. Does anyone else have any experience of these? Attached Thumbnails

7th Jul 2018, 10:10 pm	#2
linescan87 Heptode Join Date: Mar 2014 Location: Meath, Ireland Posts: 551	Re: Pye Red Box I have one of these little sets in storage, good little performers. Never had the back off. John Joe.

7th Jul 2018, 10:49 pm	#3
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,567	Re: Pye Red Box Yes....serviced quite a few of these when at Philips. If yours has the 'piggyback' microcontroller, its the early version. Later versions did away with the adaptor and everything was contained in one chip. There were a few problems with plated through connections resulting in 88 appearing in the display. The RGB pots were a common failing. I did a service article for these in 'Television' but can't remember the actual issue....I'll see if I can find it. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

7th Jul 2018, 10:51 pm	#4
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Pye Red Box The only problem I had with these was a dead set symptom with '88' in the display. Very intermittent and due to dry joints through the layered print. John. Snap! J.

9th Jul 2018, 1:04 pm	#6
Studio263 Octode Join Date: Apr 2007 Location: Hampshire, UK. Posts: 1,576	Re: Pye Red Box I knew it couldn't last... Watching the set over the weekend I noticed that every minute or so the width would drop, the height would increase and the overall brightness level would fall. A few seconds later things would return to normal, then the process repeated itself. A change in the HT voltage would do all these things, but why? A look at the chassis showed the answer. The 'set HT' control was that horrid type with the orange middle. Out it came and in went a new 4k7 preset. Things were fine after that, I set the main HT rail to 27V with a normal picture displayed. While I was there, I noticed that the start up circuit uses a tiny thermistor in a little plastic box. I'd forgotten all about those, I think the Hitachi had them too. We used to get through quite a few, I suspect that the circuit would have to be modified if it failed now. As it was the soldering underneath it was a bit suspect, so I ran the iron over that too.

9th Jul 2018, 2:40 pm	#7
Jac Heptode Join Date: Jun 2006 Location: Eindhoven, Netherlands. Posts: 642	Re: Pye Red Box I have a Philips version still in the workshop to check video signals. I had to resolder the vert deflection IC and the connections to the deflection unit. Picture is acceptable, sound is nothing to write home about. But it takes little space and has proved worthwile for testing. Jac

9th Jul 2018, 7:01 pm	#8
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,819	Re: Pye Red Box I’ve got 2 of the Philips variants of these, one in the dark grey finish with a thin red stripe under the screen, and a white one. The white one has an odd fault, which I think could be the micro, it comes on with full volume and brightness, also sometimes no colour, and it’s not adjustable with the front controls. The colour slowly fades in after a while though! The grey one works fine, despite being in awful condition! It survived being posted to me, the seller didn’t pack it in anything, just gaffer taped Jiffy bags over the front and back... it is missing it’s plastic screen cover, and the speaker is knackered. One day I might go and retrieve it from my storage unit and see if it still works! Regards Lloyd Attached Thumbnails

28th Aug 2018, 1:02 pm	#10
Studio263 Octode Join Date: Apr 2007 Location: Hampshire, UK. Posts: 1,576	Re: Pye Red Box Another, rather rougher example of this set has now appeared here. It's a Philips one this time, dark grey. There were endless faults to begin with but many resolved to iffy preset potentiometers, a bit of a bugbear in this model. This left an odd one-line frame jitter which was only really objectionable on certain scenes but always there if you looked. Dropping the height stopped it, which turned out to be the clue. In these sets, the line and frame stages both run from a +27V line from the power supply. This is smoothed by two 1000uF electrolytics, which are of the later blue Philips type. One read 930uF on the meter, the other about 950uF. Changing both cleared the fault, the frame stage must have been putting ripple back on the line when under full load. The originals are 50V rated but I don't keep those. Instead, I used some 35V Matsushita ones (M series) which are much easier to come by. The frame coil coupling capacitor was the same type and just as duff, so I changed that one too.