Philips TV set for 441 lines - UK Vintage Radio Repair and Restoration Discussion Forum

FERNSEH · 21st Mar 2006, 1:32 pm

The attachment shows the picture of a 1947 9" Philips TV set designed to operate on the 441 line transmissions from the Eiffel Tower transmitter.

I intent to restore the set back to working order and return it to it's owner in France.

No service documentation can be found for the set so I'll just have trace though the circuits. It could be likely that as the set was designed in Holland many of the circuit features will be similar to those found in the post-war British Philips TV receivers.

The line output stage employs two parallel connected UL44s. The CRT is a MW22-7. The majority of the valves are U series B8A rimlock types.

The set is designated as TF384.

DFWB

peter_scott · 21st Mar 2006, 5:37 pm

https://www.vintage-radio.net/forum/...&highlight=dog

This thread might be useful to you.

Peter

FERNSEH · 21st Mar 2006, 8:36 pm

Hi Peter,
The French version of the "Little Dog" differs in having a broadcast radio facility. The version for Holland could have been used on an experimental 567 line standard.
Perhaps Roland could confirm this?

DFWB.

FERNSEH · 26th Apr 2006, 10:37 pm

Today, I removed the chassis and CRT from the Philips TF384.

One valve is missing and as no service information is available for this set it became necessary to remove the chassis and trace out the connections to the missing valve. It shares a sub-assembly with the UL41 frame output valve and the two UL44s employed in the line output stage.
It was found that the missing valve is connected via an inductor to the anode of the video amplifier. Further examination of the connections confirm the the function of the valve as the white spot limiter. I'd guess that the correct valve is an UB41 double-diode. The other section operates in the sound circuit and is a series interference limiter.

The set employs an unusual EHT rectifier valve, an EA40. Note that the valve has no top cap.

DFWB.

Duke_Nukem · 27th Apr 2006, 8:13 am

Quote:

It could be likely that as the set was designed in Holland many of the circuit features will be similar to those found in the post-war British Philips TV receivers.

IIRC, the UKh Philips sets were designed in Britain so may well be different. They did try a design in Holland for the UK market but there were a lot of problems so the design of such sets remained in Britain. Can't remember where I read this but I'm pretty sure it was in the excellent book "The Setmakers".

UK Philips sets around that time would have been stuffed full of EF50's. Were UL41/UL44's really available in 1947 ?

TTFN,
Jon

FERNSEH · 27th Apr 2006, 11:09 am

Hi Jon,
I'm getting second thoughts about the TF384. 1947 could be a bit early and it's more likely the set was released in 1948. The design of the set is unlike any of the the UK Philips TV receivers. The 385U was designed in Holland and is similar to the TF/TX390 and those sets were introduced in late 1949? Like the TF384 they used the U series B8A base valves.

I believe that the intro date for the B8A Rimlock series of valves was 1947.

I don't think the EF50 was ever employed in continental TV sets.

DFWB.

FERNSEH · 5th Jun 2006, 11:23 am

Progress of the electrical restoration has been confined to replacing some perished rubber wiring. As for the missing UB41 valve, I've had no luck finding one.
It will be noticed that the front safety glass and escutcheon were missing. The only answer to this problem is to make the parts and this has now been done.

DFWB.

ppppenguin · 5th Jun 2006, 11:43 am

Quote:

Originally Posted by FERNSEH

As for the missing UB41 valve, I've had no luck finding one.

I suppose the simple cheat is a couple of suitable semiconductor diodes and a 190R (19V/100mA) resistor to keep the heater chain intact. Time to wash mouth out with

BassoonBloke · 5th Jun 2006, 11:55 am

Hello there,

I've just had a quick look on the web and there is at least one company who (apparently) has UB41's for sale, Bull is one of them and they are listed at about £4 each.

There is a small possibility i have one of these at home. If i get a chance i will have a look.
All the best,
Alan.

FERNSEH · 11th Jun 2006, 2:51 pm

The wood escutcheon has been painted black and a piece of glass has been cut to size to fit in it.
This week I will turn my attention to the electronic restoration.

The set will require another piece of glass cut to size for the radio tuning scale.

DFWB.

wiwior · 12th Jun 2006, 10:54 pm

Hello David,

It's very beautiful thank you very much

.

See you soon

regards

wilfrid

FERNSEH · 17th Jun 2006, 11:37 pm

The attachment shows the underside of the Philips TF384. The receiver is in very good condition. I've got to determine if the vision section employs a TRF or superhet circuit. I'd guess it will be the latter. Also,the radio section will have an IF of 455 to 470Kc/s, but what of the TV sound?
The valve line-up in the sound section is: UCH41 FC, UAF41 IF and detector,
UAF42 audio amplifier and an UL41 for the output valve.

The set is tuned to the Paris 441 line transmitter. 42Mc/s sound and 46Mc/s vision.

DFWB.

FERNSEH · 21st Jun 2006, 9:18 pm

Considering that the Paris 441 line transmitter closed down in 1956 the only likelyhood of this set ever been used after that event would be as a radio receiver.

I'm attempting to reform the HT smoothing electrolytic capacitors. The trick I'm employing is to a connect an 1N4007 diode in series with a 220Kohm resistor to the capacitor and use the mains supply.
The value of the resistor can be reduced in stages.
It has worked for me in the past with varying degrees of sucess. It is a very slow process and can take upto 24 hours.

DFWB.

FERNSEH · 21st Jul 2006, 10:47 pm

The attachment shows the rather strange power supply circuits employed in the receiver.
Note the heater supply to the UB41 double diode.

DFWB.

FERNSEH · 28th Oct 2006, 11:28 am

It was July 21st when I posted the restoration progress of the Philips TF384.

Since that date I've have identified more circuits in the receiver.
The valve heaters are arranged in four series chains. On television all four chains are in use and on radio only one operates.
The set is designed for 125 and 220 volt AC mains supplies and the heaters are supplied from the 125 tap on the mains transformer.
As one of the two UY41 HT rectifiers is in series with the four UF42 RF amplifier heaters, when the set is on radio and the television valves are switched out only one UY41 supplies the HT.
Note that on TV the UCH41 radio FC heater is bypassed so it seems that the sound stage is definately a TRF circuit.
I've got concerns about the UB41 and it's position in the HT negative return.
It will be a good idea to substitute it's heater for a 190 ohm resistor until I'm entirely satisfied with the completed restoration.

Today, I'll summons up some courage and connect the set to the mains, on radio first.

DFWB.

Mikey405 · 28th Oct 2006, 11:52 am

I saw a similar set (but not identical) in the Philips museum in Eindhoven. I don't know what model it was or if it was anything like that same as Wilfrid's / David's set.

From Mike.

FERNSEH · 28th Oct 2006, 1:13 pm

Hi Mike,
The set on display in the Philips museum will be a receiver for Holland's experimental 567 line transmissions.

The transmitter sync pulse dividers would have been 9 X 9 X 7 = 567

DFWB.

FERNSEH · 30th Oct 2006, 12:13 am

Quote:

Originally Posted by FERNSEH

Today, I'll summons up some courage and connect the set to the mains, on radio first.

One day later and I have connected the set to the variac. Only the radio valves have been inserted into their sockets. Starting with a low voltage from the variac the voltage was slowly increased but I was getting no results, no indication of HT volts. To keep the story short the UAF42 AF amplifier/detector was found to have an OC heater.
For the time being I've fitted an air filled UF42 to maintain heater chain continuity.
The HT volts are 230 volts, which is about right. The reformed smoothing capacitors seem to be holding up OK.
So the search is on for an UAF42, also I will need three UF42s.

DFWB.

FERNSEH · 31st Oct 2006, 2:38 am

My Eddystone 670 radio receiver has donated an UAF42 to the TF384 sound section..
After fitting the valve to the TV set the good news is that the radio works OK on medium and long waves, albeit it's a bit hissy, the UCH41 frequency changer valve might need replacing.
The next part of the set to test the TRF vision receiver.
The vision amplifier consists of four UF42 pentodes followed by another UF42 which serves as an anode bend detector and video output valve.

DFWB.

FERNSEH · 15th Dec 2006, 10:49 pm

It's not good news this time. After the success with the radio part of the set I decided to turn my attention to the vision stage.
Wilfrid kindly supplied me with four UF42 valves, the UF42 is not an easy valve to find anywhere.
The four RF pentodes were fitted into the vision TRF amplifier along with the UY41 HT rectifier. The set was switched on and it was soon noted that the valve heaters were lit. No problems so far. However, it was not possible to monitor the video waveform at the vision detector as this set employs an anode bend detector and that valve also is the video amplifier, again an UF42.
The video amplifier/anode bend detector valve heater is supplied from another heater chain.
So, I decided to fit remainer of the valves. The video amplifier heater is in series with an UCH21 and one of the UL44 line output valves.

The set was again switched on, the heaters came up but shortly after there was an almighty bang and I soon discovered that the UF42 video valve and an UL44 had gone oc heaters. I'll have to be more careful next time, these are rare valves.

DFWB.

21st Mar 2006, 1:32 pm	#1
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Philips TV set for 441 lines The attachment shows the picture of a 1947 9" Philips TV set designed to operate on the 441 line transmissions from the Eiffel Tower transmitter. I intent to restore the set back to working order and return it to it's owner in France. No service documentation can be found for the set so I'll just have trace though the circuits. It could be likely that as the set was designed in Holland many of the circuit features will be similar to those found in the post-war British Philips TV receivers. The line output stage employs two parallel connected UL44s. The CRT is a MW22-7. The majority of the valves are U series B8A rimlock types. The set is designated as TF384. DFWB Attached Thumbnails

21st Mar 2006, 5:37 pm	#2
peter_scott Dekatron Join Date: May 2003 Location: Edinburgh, UK. Posts: 3,274	Re: Philips TV set for 441 lines https://www.vintage-radio.net/forum/...&highlight=dog This thread might be useful to you. Peter

21st Mar 2006, 8:36 pm	#3
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines Hi Peter, The French version of the "Little Dog" differs in having a broadcast radio facility. The version for Holland could have been used on an experimental 567 line standard. Perhaps Roland could confirm this? DFWB.

26th Apr 2006, 10:37 pm	#4
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines Today, I removed the chassis and CRT from the Philips TF384. One valve is missing and as no service information is available for this set it became necessary to remove the chassis and trace out the connections to the missing valve. It shares a sub-assembly with the UL41 frame output valve and the two UL44s employed in the line output stage. It was found that the missing valve is connected via an inductor to the anode of the video amplifier. Further examination of the connections confirm the the function of the valve as the white spot limiter. I'd guess that the correct valve is an UB41 double-diode. The other section operates in the sound circuit and is a series interference limiter. The set employs an unusual EHT rectifier valve, an EA40. Note that the valve has no top cap. DFWB. Attached Thumbnails

27th Apr 2006, 11:09 am	#6
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines Hi Jon, I'm getting second thoughts about the TF384. 1947 could be a bit early and it's more likely the set was released in 1948. The design of the set is unlike any of the the UK Philips TV receivers. The 385U was designed in Holland and is similar to the TF/TX390 and those sets were introduced in late 1949? Like the TF384 they used the U series B8A base valves. I believe that the intro date for the B8A Rimlock series of valves was 1947. I don't think the EF50 was ever employed in continental TV sets. DFWB.

5th Jun 2006, 11:23 am	#7
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines Progress of the electrical restoration has been confined to replacing some perished rubber wiring. As for the missing UB41 valve, I've had no luck finding one. It will be noticed that the front safety glass and escutcheon were missing. The only answer to this problem is to make the parts and this has now been done. DFWB. Attached Thumbnails

5th Jun 2006, 11:55 am	#9
BassoonBloke Pentode Join Date: Feb 2006 Location: East London, UK. Posts: 231	Re: Philips TV set for 441 lines Hello there, I've just had a quick look on the web and there is at least one company who (apparently) has UB41's for sale, Bull is one of them and they are listed at about £4 each. There is a small possibility i have one of these at home. If i get a chance i will have a look. All the best, Alan.

11th Jun 2006, 2:51 pm	#10
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines The wood escutcheon has been painted black and a piece of glass has been cut to size to fit in it. This week I will turn my attention to the electronic restoration. The set will require another piece of glass cut to size for the radio tuning scale. DFWB. Attached Thumbnails

12th Jun 2006, 10:54 pm	#11
wiwior Tetrode Join Date: Apr 2006 Location: 60510 la Neuville en Hez France Posts: 71	Re: Philips TV set for 441 lines Hello David, It's very beautiful thank you very much . See you soon regards wilfrid

17th Jun 2006, 11:37 pm	#12
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines The attachment shows the underside of the Philips TF384. The receiver is in very good condition. I've got to determine if the vision section employs a TRF or superhet circuit. I'd guess it will be the latter. Also,the radio section will have an IF of 455 to 470Kc/s, but what of the TV sound? The valve line-up in the sound section is: UCH41 FC, UAF41 IF and detector, UAF42 audio amplifier and an UL41 for the output valve. The set is tuned to the Paris 441 line transmitter. 42Mc/s sound and 46Mc/s vision. DFWB. Attached Thumbnails

21st Jun 2006, 9:18 pm	#13
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines Considering that the Paris 441 line transmitter closed down in 1956 the only likelyhood of this set ever been used after that event would be as a radio receiver. I'm attempting to reform the HT smoothing electrolytic capacitors. The trick I'm employing is to a connect an 1N4007 diode in series with a 220Kohm resistor to the capacitor and use the mains supply. The value of the resistor can be reduced in stages. It has worked for me in the past with varying degrees of sucess. It is a very slow process and can take upto 24 hours. DFWB. Attached Thumbnails

21st Jul 2006, 10:47 pm	#14
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines The attachment shows the rather strange power supply circuits employed in the receiver. Note the heater supply to the UB41 double diode. DFWB. Attached Thumbnails

28th Oct 2006, 11:28 am	#15
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines It was July 21st when I posted the restoration progress of the Philips TF384. Since that date I've have identified more circuits in the receiver. The valve heaters are arranged in four series chains. On television all four chains are in use and on radio only one operates. The set is designed for 125 and 220 volt AC mains supplies and the heaters are supplied from the 125 tap on the mains transformer. As one of the two UY41 HT rectifiers is in series with the four UF42 RF amplifier heaters, when the set is on radio and the television valves are switched out only one UY41 supplies the HT. Note that on TV the UCH41 radio FC heater is bypassed so it seems that the sound stage is definately a TRF circuit. I've got concerns about the UB41 and it's position in the HT negative return. It will be a good idea to substitute it's heater for a 190 ohm resistor until I'm entirely satisfied with the completed restoration. Today, I'll summons up some courage and connect the set to the mains, on radio first. DFWB. Attached Thumbnails

28th Oct 2006, 11:52 am	#16
Mikey405 Octode Join Date: Jul 2006 Location: Solihull, West Midlands and Beaford, Devon Posts: 1,626	Re: Philips TV set for 441 lines I saw a similar set (but not identical) in the Philips museum in Eindhoven. I don't know what model it was or if it was anything like that same as Wilfrid's / David's set. From Mike. Attached Thumbnails

28th Oct 2006, 1:13 pm	#17
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines Hi Mike, The set on display in the Philips museum will be a receiver for Holland's experimental 567 line transmissions. The transmitter sync pulse dividers would have been 9 X 9 X 7 = 567 DFWB.

31st Oct 2006, 2:38 am	#19
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines My Eddystone 670 radio receiver has donated an UAF42 to the TF384 sound section.. After fitting the valve to the TV set the good news is that the radio works OK on medium and long waves, albeit it's a bit hissy, the UCH41 frequency changer valve might need replacing. The next part of the set to test the TRF vision receiver. The vision amplifier consists of four UF42 pentodes followed by another UF42 which serves as an anode bend detector and video output valve. DFWB.

15th Dec 2006, 10:49 pm	#20
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Philips TV set for 441 lines It's not good news this time. After the success with the radio part of the set I decided to turn my attention to the vision stage. Wilfrid kindly supplied me with four UF42 valves, the UF42 is not an easy valve to find anywhere. The four RF pentodes were fitted into the vision TRF amplifier along with the UY41 HT rectifier. The set was switched on and it was soon noted that the valve heaters were lit. No problems so far. However, it was not possible to monitor the video waveform at the vision detector as this set employs an anode bend detector and that valve also is the video amplifier, again an UF42. The video amplifier/anode bend detector valve heater is supplied from another heater chain. So, I decided to fit remainer of the valves. The video amplifier heater is in series with an UCH21 and one of the UL44 line output valves. The set was again switched on, the heaters came up but shortly after there was an almighty bang and I soon discovered that the UF42 video valve and an UL44 had gone oc heaters. I'll have to be more careful next time, these are rare valves. DFWB.