Philips Style70 LOPT failures - UK Vintage Radio Repair and Restoration Discussion Forum

System A · 28th Aug 2006, 8:29 pm

My Philips Style70 has given up with the LOPT failing again!
This is the second one it's had in 10 years. Is this just my luck or were the replacement LOPTs poor as well?
I wonder if a Thorn jelly-pot would adapt? Anybody ever tried one before?
Regards GP.

Steve_P · 28th Aug 2006, 11:50 pm

What else did you change as well as the LOPT?

Cheers,

Steve P

System A · 29th Aug 2006, 6:58 am

Checked everthing: line output valve, boost etc.
It's definitely the LOPT.
It is the model with the clock timer fitted, it's even got the magazine rack stand.
Do you think something could be causing the failure?
Regards GP.

Focus Diode · 29th Aug 2006, 2:00 pm

Unfortunate indeed. Philips LOPTs do have a poor reputation from the Style 70 series onwards.

On a working set checking the boost voltage and keeping it as low as possible does help prolong life but is no guarantee.

Have you tried removing the overwind in case it's that which has failed?

Cheers,
Brian

Welsh Anorak · 29th Aug 2006, 4:54 pm

Hi there
Probably the magazine rack's to blame!
Seriously, I've had a look in my pile of 'things that will come in useful one day' and there's a Philips LOPT, brand new in its box! Not sure if it's the Style 70 one, though. The number on the transformer is 3113 108 20913 and on the box is 3113 982 86791. There's one 7-way long plug, a base for the DY86 and the EHT lead, and it sits on a metal trapezium-shaped plate. Is it the one?
Send me a PM if it is - it's yours for a tenner (including the postage, of course)

Glyn

Steve_P · 29th Aug 2006, 7:23 pm

Glyn - Might be worth putting a photo up so Gary can make sure it's the right one. If it is, I should think he'll buy....

Gary - Change C415 on the timebase board, and make sure it's clean at the connectors. Also check/replace C501, C502, C417, C418. Also check the HT voltage on the screen grid of V500 and R429 and C416.

Also scope V500 control grid and make sure the drive waveform is clean.

It is also a good idea (in my humble opinion) not to operate the standards switch with the set powered. The 'Shock' isn't good for the LOPT.

Cheers,

Steve P

FERNSEH · 2nd Sep 2006, 2:11 pm

Many years ago I fitted a BRC 1400 line output transformer into a Philips 19TG170A Style Seventy TV set.

The original scan coils did not match the jelly pot so the 1400 coils were installed also.

The inspiration for the project was in reponse to an article in the Television magazine where a contributor installed a jelly pot into his Bush TV125.

DFWB.

Steve_P · 2nd Sep 2006, 2:32 pm

This article was in Sept 81 edition of The Mag, and it was written by Keith Hamer and Gary Smith. Didn't mention the coils being incompatible though. Want it posting here?

Cheers,

Steve P

dazzlevision · 3rd Sep 2006, 7:40 am

Hi,

If I recall correctly, the Bush TV125 LOPT mod in "Television" magazine was 625 only - not 405-625 switchable. Of course, you'll also need the clip-on EHT tripler unit for the Thorn 1400 LOPT.

Another possibility is to retrofit a Philips 210 or 300 series LOPT (also used in the Pye/Ekco 368 chassis) into your Style 70 set - I think the circuit is similar and the scan coils should not require changing.

The 210 & 300 series followed on from the Style 70 range. Although they also suffered from unreliable LOPT, they should be easier to source.

Regards,

Dazzlevision

Steve_P · 3rd Sep 2006, 7:33 pm

Hi Gary, and others who wanted this.

Sorry it took so long, but I waited till the rain had stopped before I went to the Garage. Hope the delay - made longer by me forgetting the year - it is in fact 1982 - hasn't been too great.

Dazzlevision points out quite rightly that the Mod described is 625 Line only. And I don't know if it'll suit your scan coils on the Philips Sets. Only one way to find out!!!

Cheers,

Steve P

28th Aug 2006, 8:29 pm	#1
System A Pentode Join Date: Feb 2006 Location: County Durham, UK. Posts: 234	Philips Style70 LOPT failures My Philips Style70 has given up with the LOPT failing again! This is the second one it's had in 10 years. Is this just my luck or were the replacement LOPTs poor as well? I wonder if a Thorn jelly-pot would adapt? Anybody ever tried one before? Regards GP.

28th Aug 2006, 11:50 pm	#2
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: philips style 70 lopts What else did you change as well as the LOPT? Cheers, Steve P __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

29th Aug 2006, 6:58 am	#3
System A Pentode Join Date: Feb 2006 Location: County Durham, UK. Posts: 234	Re: philips style 70 lopts Checked everthing: line output valve, boost etc. It's definitely the LOPT. It is the model with the clock timer fitted, it's even got the magazine rack stand. Do you think something could be causing the failure? Regards GP.

29th Aug 2006, 2:00 pm	#4
Focus Diode Octode Join Date: Jan 2006 Location: Borough of Gateshead, UK. Posts: 1,420	Re: philips style 70 lopts Unfortunate indeed. Philips LOPTs do have a poor reputation from the Style 70 series onwards. On a working set checking the boost voltage and keeping it as low as possible does help prolong life but is no guarantee. Have you tried removing the overwind in case it's that which has failed? Cheers, Brian

29th Aug 2006, 4:54 pm	#5
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,921	Re: philips style 70 lopts Hi there Probably the magazine rack's to blame! Seriously, I've had a look in my pile of 'things that will come in useful one day' and there's a Philips LOPT, brand new in its box! Not sure if it's the Style 70 one, though. The number on the transformer is 3113 108 20913 and on the box is 3113 982 86791. There's one 7-way long plug, a base for the DY86 and the EHT lead, and it sits on a metal trapezium-shaped plate. Is it the one? Send me a PM if it is - it's yours for a tenner (including the postage, of course) Glyn

29th Aug 2006, 7:23 pm	#6
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: philips style 70 lopts Glyn - Might be worth putting a photo up so Gary can make sure it's the right one. If it is, I should think he'll buy.... Gary - Change C415 on the timebase board, and make sure it's clean at the connectors. Also check/replace C501, C502, C417, C418. Also check the HT voltage on the screen grid of V500 and R429 and C416. Also scope V500 control grid and make sure the drive waveform is clean. It is also a good idea (in my humble opinion) not to operate the standards switch with the set powered. The 'Shock' isn't good for the LOPT. Cheers, Steve P __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

2nd Sep 2006, 2:11 pm	#7
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: philips style 70 lopts Many years ago I fitted a BRC 1400 line output transformer into a Philips 19TG170A Style Seventy TV set. The original scan coils did not match the jelly pot so the 1400 coils were installed also. The inspiration for the project was in reponse to an article in the Television magazine where a contributor installed a jelly pot into his Bush TV125. DFWB.

2nd Sep 2006, 2:32 pm	#8
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: philips style 70 lopts This article was in Sept 81 edition of The Mag, and it was written by Keith Hamer and Gary Smith. Didn't mention the coils being incompatible though. Want it posting here? Cheers, Steve P __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

3rd Sep 2006, 7:40 am	#9
dazzlevision Dekatron Join Date: Sep 2003 Location: Near Swindon, North Wiltshire, UK. Posts: 3,611	Re: philips style 70 lopts Hi, If I recall correctly, the Bush TV125 LOPT mod in "Television" magazine was 625 only - not 405-625 switchable. Of course, you'll also need the clip-on EHT tripler unit for the Thorn 1400 LOPT. Another possibility is to retrofit a Philips 210 or 300 series LOPT (also used in the Pye/Ekco 368 chassis) into your Style 70 set - I think the circuit is similar and the scan coils should not require changing. The 210 & 300 series followed on from the Style 70 range. Although they also suffered from unreliable LOPT, they should be easier to source. Regards, Dazzlevision

3rd Sep 2006, 7:33 pm	#10
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: philips style 70 lopts Hi Gary, and others who wanted this. Sorry it took so long, but I waited till the rain had stopped before I went to the Garage. Hope the delay - made longer by me forgetting the year - it is in fact 1982 - hasn't been too great. Dazzlevision points out quite rightly that the Mod described is 625 Line only. And I don't know if it'll suit your scan coils on the Philips Sets. Only one way to find out!!! Cheers, Steve P Attached Thumbnails __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?