PYE T19D Radio - UK Vintage Radio Repair and Restoration Discussion Forum

Heatercathodeshort · 3rd Oct 2008, 8:41 pm

Hello,
I bought this Pye T19D radio at a steam and vintage vehicle show.
Nobody wanted it and feeling a bit uneasy about what might happen to it at the end of the show, parted with just a single £1 coin and loaded it into the Atkinson lorry.
It sat in the workshop until I decided to attack it today. The receiver was produced around 1950 using lovely octal valves, you know the ones, the Mullard 'red' E series.
It is a conventional four valve plus rectifier arrangement with switched coverage of the short wave bands from 15-50 metres, trawler band and the usual long and medium wave. I must admit I find these receivers a bit boring repair wise but the results are well worth the effort. I removed the back and discovered a totally original chassis. No replacements appear to have been made and I suspect the set had been laid up for some years. All seemed intact so the mains was applied.
After a few moments the valves lit but the AZ31 rectifier appeared to be under some strain glowing a very faint blue from its twin anodes.
I removed the chassis, a very simple job on this well designed set and checked the resistance of the H.T. rail to chassis. 10K.....Not good and a check of the twin smoothing block proved this to be the culprit. The tags were corroded and the seal a complete mess. A check of the Sprague coupling capacitor to the grid of the EL33 proved it to be in excellent condition so this was retained. The tone correction capacitors showed a slight leak but as it turned out were quite serviceable for their purpose and they too were left in their resting place hugging the tone switch.
A smoothing electrolytic was sorted from a massive box of devices, some of which have very strange values and voltage ratings. I constantly wonder how I managed to collect so much junk! This was fitted after a struggle as the young ladies at Messrs Pye Radio had fitted the original item with incredible strength wrapping the connections firmly through the tags and soldering heavily. Switching on and connecting the bench aerial and speaker produced A howl with motor boating and a glance at the red coating on the EF39 I.F. amplifier quickly confirmed my suspicion and the usual trick as can be seen in the pictures was performed. With the screening secured to earth a mass of signals on all bands. All switches and controls were cleaned and the drive cord replaced as the original had parted many years before. [I hate re threading drive cords...] Two new pilot bulbs were fitted and the receiver tested again. The quality is truly excellent with a massive reserve of volume and is a very pleasant set to listen to. No realignment was required as the sensitivity and selectivity were well up to spec.
This was not a restoration of course but resembled very closely a typical repair that would have been carried out in a radio service dept of the 1950's.
I can hear it in the distance as I write this note. It really does sound very good...Regards, John.

Tim · 3rd Oct 2008, 9:05 pm

I have one of these on the "pile", that has been got at. Should be nice when it's going, more shorwave bands than GCHQ!!

Nickthedentist · 5th Oct 2008, 8:46 pm

Nice story, John!

I had a very similar Pye, which is now with Paul Sherwin. Mine cost a tenner from a junk shop in Selly Oak, Birmingham.

Main faults with mine were HT arcing from somewhere under the chassis, loss of metalising from the valves, and broken control knobs (they seem very frail, especially if the switches are stiff). SW reception was particularly good.

Removing the grille and applying a coat of PlastiKote Antique Gold paint with an old brush instantly transformed its appearance from shabby to presentable.

Nick.

Heatercathodeshort · 6th Oct 2008, 9:11 am

Hello Nick,
I was very lucky with this one. The knobs were stuck tight on the spindles but were in good condition. I managed to ease them off, clean the control spindles and add a touch of MS4 silicon grease from a tube I purchased in 1964.Well they did suggest it was used very sparingly....There were very many similar models produced by Pye around 1948-53 and decided to have a go at this one due to its short wave bandspread design.
It performs extremely well here in W. Sussex on a conventional outside aerial and the French stations roll in on Long wave. Have we really advanced in audio quality that much since 1948? Regards, John.

newlite4 · 6th Oct 2008, 9:39 am

I have an underlying passion for this series of sets. I have a P28 which is visually similar to this , but is the "short superhet" version using three valves plus rectifier. They do perform very well. Considering how good they are, it is surprising how cheaply they can be obtained.
Neil

Patrick Dixon · 6th Oct 2008, 10:13 am

Quote:

Originally Posted by Heatercathodeshort

A howl with motor boating and a glance at the red coating on the EF39 I.F. amplifier quickly confirmed my suspicion and the usual trick as can be seen in the pictures was performed.

Hi,

Could you explain what is the usual trick? I can't see what you mean from the photos.

Heatercathodeshort · 6th Oct 2008, 12:44 pm

Hello Patrick,
Mullard 'Red' series valves are without doubt some of the very best available. They do suffer from one fault that is more mechanical than electrical. The metallic screening coating particularly with reference to the EF39, is earthed to pin 6 via a thin fuse type wire wrapped around the bottom of the bulb at the point where it enters the Bakelite base.
Over the years the connection between the base of the metalizing and the wrapped wire deteriorates to a point where the connection is broken. When this happens the screening effect is destroyed and the I.F. stage bursts into oscillation causing the familiar motor boating and howl.
The cure is simple. Taking great care pick away at the glass base until you discover the thin wire. Solder a length of 5amp fuse wire onto this and wind it round the base of the valve a dozen times until it covers a good area of red screening. Apply the soldering iron to bond the wire together and refit the valve. If the original connection has entirely broken away, wind the wire as described then run the end down to pin 6 soldering at the base where the pin meets the Bakelite base. Hope this makes some sense. My example in the picture is very scruffy workmanship [?] I was more interested in getting the set working than appearance. I have since made a neat job of it....Regards, John.

Patrick Dixon · 6th Oct 2008, 1:18 pm

Thanks, I can see it now.

Heatercathodeshort · 6th Oct 2008, 1:25 pm

Just to add. These pics show the remedy with a rather tatty ECH35. [1] The original connecting wire at the base of the valve. [2] The wire unwrapped. [3]The new wire soldered to the original, wrapped around the red metalizing for around an 1/8 of an inch and soldered.

ajs37 · 15th Oct 2008, 4:45 pm

thanks John - just come across this problem in a Beethoven U2038 - lots of howl! I suspected the EF39 and CCH35, finding thin bits of wire breaking away from the bases.
Checked on the forum (search for EF39) and up comes your thread with the answer! Bl**dy marvellous - what a great forum!
thanks
Andy

Heatercathodeshort · 15th Oct 2008, 7:43 pm

At your service Andy as we all are! Great news! John.

3rd Oct 2008, 8:41 pm	#1
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	PYE T19D Radio Hello, I bought this Pye T19D radio at a steam and vintage vehicle show. Nobody wanted it and feeling a bit uneasy about what might happen to it at the end of the show, parted with just a single £1 coin and loaded it into the Atkinson lorry. It sat in the workshop until I decided to attack it today. The receiver was produced around 1950 using lovely octal valves, you know the ones, the Mullard 'red' E series. It is a conventional four valve plus rectifier arrangement with switched coverage of the short wave bands from 15-50 metres, trawler band and the usual long and medium wave. I must admit I find these receivers a bit boring repair wise but the results are well worth the effort. I removed the back and discovered a totally original chassis. No replacements appear to have been made and I suspect the set had been laid up for some years. All seemed intact so the mains was applied. After a few moments the valves lit but the AZ31 rectifier appeared to be under some strain glowing a very faint blue from its twin anodes. I removed the chassis, a very simple job on this well designed set and checked the resistance of the H.T. rail to chassis. 10K.....Not good and a check of the twin smoothing block proved this to be the culprit. The tags were corroded and the seal a complete mess. A check of the Sprague coupling capacitor to the grid of the EL33 proved it to be in excellent condition so this was retained. The tone correction capacitors showed a slight leak but as it turned out were quite serviceable for their purpose and they too were left in their resting place hugging the tone switch. A smoothing electrolytic was sorted from a massive box of devices, some of which have very strange values and voltage ratings. I constantly wonder how I managed to collect so much junk! This was fitted after a struggle as the young ladies at Messrs Pye Radio had fitted the original item with incredible strength wrapping the connections firmly through the tags and soldering heavily. Switching on and connecting the bench aerial and speaker produced A howl with motor boating and a glance at the red coating on the EF39 I.F. amplifier quickly confirmed my suspicion and the usual trick as can be seen in the pictures was performed. With the screening secured to earth a mass of signals on all bands. All switches and controls were cleaned and the drive cord replaced as the original had parted many years before. [I hate re threading drive cords...] Two new pilot bulbs were fitted and the receiver tested again. The quality is truly excellent with a massive reserve of volume and is a very pleasant set to listen to. No realignment was required as the sensitivity and selectivity were well up to spec. This was not a restoration of course but resembled very closely a typical repair that would have been carried out in a radio service dept of the 1950's. I can hear it in the distance as I write this note. It really does sound very good...Regards, John. Attached Thumbnails

3rd Oct 2008, 9:05 pm	#2
Tim Dekatron Join Date: Jan 2003 Location: Bradford on Avon, Wiltshire, UK. Posts: 3,310	Re: PYE T19D Radio I have one of these on the "pile", that has been got at. Should be nice when it's going, more shorwave bands than GCHQ!! __________________ "Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly."

5th Oct 2008, 8:46 pm	#3
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,844	Re: PYE T19D Radio Nice story, John! I had a very similar Pye, which is now with Paul Sherwin. Mine cost a tenner from a junk shop in Selly Oak, Birmingham. Main faults with mine were HT arcing from somewhere under the chassis, loss of metalising from the valves, and broken control knobs (they seem very frail, especially if the switches are stiff). SW reception was particularly good. Removing the grille and applying a coat of PlastiKote Antique Gold paint with an old brush instantly transformed its appearance from shabby to presentable. Nick.

6th Oct 2008, 9:11 am	#4
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: PYE T19D Radio Hello Nick, I was very lucky with this one. The knobs were stuck tight on the spindles but were in good condition. I managed to ease them off, clean the control spindles and add a touch of MS4 silicon grease from a tube I purchased in 1964.Well they did suggest it was used very sparingly....There were very many similar models produced by Pye around 1948-53 and decided to have a go at this one due to its short wave bandspread design. It performs extremely well here in W. Sussex on a conventional outside aerial and the French stations roll in on Long wave. Have we really advanced in audio quality that much since 1948? Regards, John.

6th Oct 2008, 9:39 am	#5
newlite4 Octode Join Date: Nov 2003 Location: Bath, Somerset, UK. Posts: 1,805	Re: PYE T19D Radio I have an underlying passion for this series of sets. I have a P28 which is visually similar to this , but is the "short superhet" version using three valves plus rectifier. They do perform very well. Considering how good they are, it is surprising how cheaply they can be obtained. Neil __________________ preserving the recent past, for the distant future.

6th Oct 2008, 12:44 pm	#7
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: PYE T19D Radio Hello Patrick, Mullard 'Red' series valves are without doubt some of the very best available. They do suffer from one fault that is more mechanical than electrical. The metallic screening coating particularly with reference to the EF39, is earthed to pin 6 via a thin fuse type wire wrapped around the bottom of the bulb at the point where it enters the Bakelite base. Over the years the connection between the base of the metalizing and the wrapped wire deteriorates to a point where the connection is broken. When this happens the screening effect is destroyed and the I.F. stage bursts into oscillation causing the familiar motor boating and howl. The cure is simple. Taking great care pick away at the glass base until you discover the thin wire. Solder a length of 5amp fuse wire onto this and wind it round the base of the valve a dozen times until it covers a good area of red screening. Apply the soldering iron to bond the wire together and refit the valve. If the original connection has entirely broken away, wind the wire as described then run the end down to pin 6 soldering at the base where the pin meets the Bakelite base. Hope this makes some sense. My example in the picture is very scruffy workmanship [?] I was more interested in getting the set working than appearance. I have since made a neat job of it....Regards, John.

6th Oct 2008, 1:18 pm	#8
Patrick Dixon Hexode Join Date: Aug 2007 Location: Bristol, UK. Posts: 480	Re: PYE T19D Radio Thanks, I can see it now.

6th Oct 2008, 1:25 pm	#9
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: PYE T19D Radio Just to add. These pics show the remedy with a rather tatty ECH35. [1] The original connecting wire at the base of the valve. [2] The wire unwrapped. [3]The new wire soldered to the original, wrapped around the red metalizing for around an 1/8 of an inch and soldered. Attached Thumbnails

15th Oct 2008, 4:45 pm	#10
ajs37 Heptode Join Date: Jun 2003 Location: Bristol, UK. Posts: 900	Re: PYE T19D Radio thanks John - just come across this problem in a Beethoven U2038 - lots of howl! I suspected the EF39 and CCH35, finding thin bits of wire breaking away from the bases. Checked on the forum (search for EF39) and up comes your thread with the answer! Bl**dy marvellous - what a great forum! thanks Andy

15th Oct 2008, 7:43 pm	#11
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: PYE T19D Radio At your service Andy as we all are! Great news! John.