Philips CTX-E 15" FST variant (15CT2309/05W) confirmation of HT setting. - UK Vintage Radio Repair and Restoration Discussion Forum

Mooly · 9th May 2011, 1:12 pm

I have a Philips CT2309, a rarity as its a 15" FST which I have owned from virtually new. Its 26 years old, I still have the original batteries for the original handset... and they still work it.

Anyway, I have just fixed an intermitent problem and thought I would check the HT which the normal CTX-E and S manuals always show as 125 volts.
The PCB print is marked as 150 volts and 190 volts (for the 20") for the main line derived supply (not the HT) and on mine with the main HT set to 125 volts, the 150 volt line is nearer 167. In fact all the line derived voltages marked on the PCB are higher by a similar percentage when the HT is set to 125 volts.

However, set the 150v to 150 volts and the picture loses sync, tuning disappears, the green tuning bar is blacked out... so it seems as though 125 volts probably is correct for this variant but thought I would check.

Red to black · 9th May 2011, 3:34 pm

Hi,

The reason your line output derived supplies are different/higher is because of the modified components in the line stage, ie. line tuning caps and s-correction caps etc., these will have been altered to suit the FST crt, which would have/needed different heater, focus and scanning etc. voltages.
The 'mains' HT should remain the same however (125V) as they likely would not have wanted to produce a re-designed lopt for just one or two late models..

There would have been a supplement issued for this specific model, detailing the changes specific to that model, to be added to the basic chassis diagram/manual, as this was, and still is the 'Philips Way'.

The board markings will have been marked up across the entire range, and will therefore be silk screened for the basic range, as your model was introduced ca.1984, this was a 'late' model in the range and they will have just used existing boards/tooling etc., and probably not bothered updating the silk screening (for one or two late models), as this model was about to be / if not already superseded.

Philips always seemed to overlap the production runs/new chassis introductions side by side for a short while.

Cheers,
Baz

Ps. I cannot recall ever seeing this model, an FST CTX-E

well I live and learn!

Welsh Anorak · 9th May 2011, 4:36 pm

Hi
Agreed - ignore the board markings and set it for 125v. I'm sure I've seen one of these (with 'FST' written in the corner) - I imagined it would be a KT4 which looked similar but found our old friend in there!
Glyn

Mooly · 9th May 2011, 7:08 pm

Thanks for the info, it makes sense actually.

Apart from this one set, I too can't recall seeing another FST like this... it's a little belter though. I fitted a Lithium coin cell in place of the Ni-Cad backup battery around 10 years or more ago and it's still going strong. In fact it's never had a component failure, and I'm ashamed to say the intermittent fault appears to have been no more than a DJ. I thought I got them all 26 years ago, so I suppose it's entitled!

Mooly · 10th May 2011, 7:41 am

Well this is the one. Not really sure how common it was but I certainly never came across another in all the thousands of sets we dealt with.
Have to use it with a freeview source now of course and the Samsung DVD has 4:3 pan and scan mode which is great. Thats a little UHF modulator at the bottom power via a rewired scart to give 5 volts... pity the chassis didn't have a scart input and full isolation.

The geometrys correct with an "old" 4:3 test card

just if anyone wondered...

9th May 2011, 1:12 pm	#1
Mooly Octode Join Date: May 2011 Location: Lancashire, UK. Posts: 1,351	Philips CTX-E 15" FST variant (15CT2309/05W) confirmation of HT setting. I have a Philips CT2309, a rarity as its a 15" FST which I have owned from virtually new. Its 26 years old, I still have the original batteries for the original handset... and they still work it. Anyway, I have just fixed an intermitent problem and thought I would check the HT which the normal CTX-E and S manuals always show as 125 volts. The PCB print is marked as 150 volts and 190 volts (for the 20") for the main line derived supply (not the HT) and on mine with the main HT set to 125 volts, the 150 volt line is nearer 167. In fact all the line derived voltages marked on the PCB are higher by a similar percentage when the HT is set to 125 volts. However, set the 150v to 150 volts and the picture loses sync, tuning disappears, the green tuning bar is blacked out... so it seems as though 125 volts probably is correct for this variant but thought I would check.

9th May 2011, 3:34 pm	#2
Red to black Nonode Join Date: Mar 2010 Location: Sunderland, Tyne and Wear, UK. Posts: 2,474	Re: Philips CTX-E 15" FST variant (15CT2309/05W) confirmation of HT setting. Hi, The reason your line output derived supplies are different/higher is because of the modified components in the line stage, ie. line tuning caps and s-correction caps etc., these will have been altered to suit the FST crt, which would have/needed different heater, focus and scanning etc. voltages. The 'mains' HT should remain the same however (125V) as they likely would not have wanted to produce a re-designed lopt for just one or two late models.. There would have been a supplement issued for this specific model, detailing the changes specific to that model, to be added to the basic chassis diagram/manual, as this was, and still is the 'Philips Way'. The board markings will have been marked up across the entire range, and will therefore be silk screened for the basic range, as your model was introduced ca.1984, this was a 'late' model in the range and they will have just used existing boards/tooling etc., and probably not bothered updating the silk screening (for one or two late models), as this model was about to be / if not already superseded. Philips always seemed to overlap the production runs/new chassis introductions side by side for a short while. Cheers, Baz Ps. I cannot recall ever seeing this model, an FST CTX-E well I live and learn! __________________ I don't suffer from Insanity. I enjoy every minute of it. Last edited by Red to black; 9th May 2011 at 3:56 pm. Reason: clarification

9th May 2011, 4:36 pm	#3
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,916	Re: Philips CTX-E 15" FST variant (15CT2309/05W) confirmation of HT setting. Hi Agreed - ignore the board markings and set it for 125v. I'm sure I've seen one of these (with 'FST' written in the corner) - I imagined it would be a KT4 which looked similar but found our old friend in there! Glyn

9th May 2011, 7:08 pm	#4
Mooly Octode Join Date: May 2011 Location: Lancashire, UK. Posts: 1,351	Re: Philips CTX-E 15" FST variant (15CT2309/05W) confirmation of HT setting. Thanks for the info, it makes sense actually. Apart from this one set, I too can't recall seeing another FST like this... it's a little belter though. I fitted a Lithium coin cell in place of the Ni-Cad backup battery around 10 years or more ago and it's still going strong. In fact it's never had a component failure, and I'm ashamed to say the intermittent fault appears to have been no more than a DJ. I thought I got them all 26 years ago, so I suppose it's entitled!

10th May 2011, 7:41 am	#5
Mooly Octode Join Date: May 2011 Location: Lancashire, UK. Posts: 1,351	Re: Philips CTX-E 15" FST variant (15CT2309/05W) confirmation of HT setting. Well this is the one. Not really sure how common it was but I certainly never came across another in all the thousands of sets we dealt with. Have to use it with a freeview source now of course and the Samsung DVD has 4:3 pan and scan mode which is great. Thats a little UHF modulator at the bottom power via a rewired scart to give 5 volts... pity the chassis didn't have a scart input and full isolation. The geometrys correct with an "old" 4:3 test card just if anyone wondered... Attached Thumbnails