https://golbornevintageradio.co.uk/forum/ Mon, 20 Apr 2026 04:10:54 +0000 MyBB https://golbornevintageradio.co.uk/forum/showthread.php?tid=9562 Mon, 26 Jan 2026 21:35:27 +0000 LENINGRAD T2]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9562 CCIR - known
819F - known
625B - regional; early VHF system; CCIR C; used in Belgium, Italy, the Netherlands, and Luxembourg, discontinued in 1977; modulation AM, positive, sound +5.5 MHz
625F - regional; CCIR L; used in France, Luxembourg; start 1963, discontinued in 2011; modulation AM, positive, sound - 6.5 MHz

  Sony TV-112UM CCIR.jpeg (Size: 818.45 KB / Downloads: 26)

  Sony TV-112UM 819F.jpeg (Size: 861.85 KB / Downloads: 24)

  Sony TV-112UM 625B.jpeg (Size: 906.38 KB / Downloads: 20)

  Sony TV-112UM 625F.jpeg (Size: 876.13 KB / Downloads: 26) ]]> CCIR - known
819F - known
625B - regional; early VHF system; CCIR C; used in Belgium, Italy, the Netherlands, and Luxembourg, discontinued in 1977; modulation AM, positive, sound +5.5 MHz
625F - regional; CCIR L; used in France, Luxembourg; start 1963, discontinued in 2011; modulation AM, positive, sound - 6.5 MHz

  Sony TV-112UM CCIR.jpeg (Size: 818.45 KB / Downloads: 26)

  Sony TV-112UM 819F.jpeg (Size: 861.85 KB / Downloads: 24)

  Sony TV-112UM 625B.jpeg (Size: 906.38 KB / Downloads: 20)

  Sony TV-112UM 625F.jpeg (Size: 876.13 KB / Downloads: 26) ]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9550 Sat, 20 Dec 2025 13:37:34 +0000 Panrock]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9550
Narrow-Bandwidth Television Association • View topic - 80-line Nipkow monitor

For this project, I shall be using the Don Lee 80-line mechanical standard from the US. The 500 mm Nipkow Disc was ordered (and paid for!) yesterday. I've been told I should have it on January 9th.

Steve]]>
Narrow-Bandwidth Television Association • View topic - 80-line Nipkow monitor

For this project, I shall be using the Don Lee 80-line mechanical standard from the US. The 500 mm Nipkow Disc was ordered (and paid for!) yesterday. I've been told I should have it on January 9th.

Steve]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9545 Sun, 07 Dec 2025 13:36:42 +0000 LENINGRAD T2]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9545 https://lampes-et-tubes.info/wm/Tonne-Se...System.pdf by Wolfgang-D. Schröer about early television in Germany. He told me I would definitely be interested.
I didn't think it would be that interesting.

The content of the article is copyrighted, so I will only provide a brief comment here, also providing information about the source and author.

When the radio exhibition in Berlin ended in 1935 with a demonstration of television systems, the great military potential of this new technology was recognized. At the same time, the development of "civilian" television seemed unprofitable. The Reich Post had appropriate financial resources. Financing began for Telefunken and Fernseh A.G. Development began on a targeting system design, consisting of a camera in the nose of the bomb – codenamed Tonne, a transmitter with power supply in the tail of the bomb, and a television receiver on board the aircraft – codenamed Seedorf. The bomb was radio-controlled by the pilot. The system was designed to be small and lightweight, and stable in operation under various environmental conditions. The first prototype camera, from 1940, measured 16x16x32 cm. The camera had a viewing angle of 15-30 degrees. It had a windshield defrosting system and automatic aperture control. A new type of receiver tube, the Super Ikonoskop IS 9, was produced, which operated even in low light conditions at 50 lux. The first versions had 29 tubes – primarily RV 12 P 2000 pentodes – and weighed 28 kg, including the power supply and batteries. The transmitter operated on a 441-line system with a frequency above 400 MHz. The biggest challenge was synchronizing the transmitter's images with the receiver. For this reason, both devices used quartz generators. The transmitter had a power of 20 W. It included Urdox gas resistors and a dedicated oscillator – a TU50 tube with a Lecher system. The tube had a heater current of 6.5 A and a voltage of 1.4 V. The anode voltage was 800 V. The tube's very low internal capacitance guaranteed the transmitter's stability. To achieve good brightness, the CRT was powered by 12 KV and was only 30 cm long – the LB20 model. The screen had a diameter of 12 x 15 cm. Ultimately, television images were obtained from a distance of 400 km and the ability to control bombs 50 km from the target. However, the project ended in failure. Perhaps the weakest link turned out to be the human factor – the pilot, who was unable to control the aircraft and the bomb and analyze the image on the screen in an emotional situation on board the aircraft, in combat conditions. I discovered that field trials of the system were conducted, among other places, 20 km from my home. I don't think anyone knows this story. The article is very comprehensive and rich in technical information. It undoubtedly sheds new and interesting light on the development of television in Germany. The author has done a great job.]]> https://lampes-et-tubes.info/wm/Tonne-Se...System.pdf by Wolfgang-D. Schröer about early television in Germany. He told me I would definitely be interested.
I didn't think it would be that interesting.

The content of the article is copyrighted, so I will only provide a brief comment here, also providing information about the source and author.

When the radio exhibition in Berlin ended in 1935 with a demonstration of television systems, the great military potential of this new technology was recognized. At the same time, the development of "civilian" television seemed unprofitable. The Reich Post had appropriate financial resources. Financing began for Telefunken and Fernseh A.G. Development began on a targeting system design, consisting of a camera in the nose of the bomb – codenamed Tonne, a transmitter with power supply in the tail of the bomb, and a television receiver on board the aircraft – codenamed Seedorf. The bomb was radio-controlled by the pilot. The system was designed to be small and lightweight, and stable in operation under various environmental conditions. The first prototype camera, from 1940, measured 16x16x32 cm. The camera had a viewing angle of 15-30 degrees. It had a windshield defrosting system and automatic aperture control. A new type of receiver tube, the Super Ikonoskop IS 9, was produced, which operated even in low light conditions at 50 lux. The first versions had 29 tubes – primarily RV 12 P 2000 pentodes – and weighed 28 kg, including the power supply and batteries. The transmitter operated on a 441-line system with a frequency above 400 MHz. The biggest challenge was synchronizing the transmitter's images with the receiver. For this reason, both devices used quartz generators. The transmitter had a power of 20 W. It included Urdox gas resistors and a dedicated oscillator – a TU50 tube with a Lecher system. The tube had a heater current of 6.5 A and a voltage of 1.4 V. The anode voltage was 800 V. The tube's very low internal capacitance guaranteed the transmitter's stability. To achieve good brightness, the CRT was powered by 12 KV and was only 30 cm long – the LB20 model. The screen had a diameter of 12 x 15 cm. Ultimately, television images were obtained from a distance of 400 km and the ability to control bombs 50 km from the target. However, the project ended in failure. Perhaps the weakest link turned out to be the human factor – the pilot, who was unable to control the aircraft and the bomb and analyze the image on the screen in an emotional situation on board the aircraft, in combat conditions. I discovered that field trials of the system were conducted, among other places, 20 km from my home. I don't think anyone knows this story. The article is very comprehensive and rich in technical information. It undoubtedly sheds new and interesting light on the development of television in Germany. The author has done a great job.]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9515 Tue, 21 Oct 2025 04:19:57 +0000 Desmond]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9515 The above statement sounds quite obvious and reasonable.
I bring this up because I am seeing so very many requests for help on C.R.T. TV Repair forums where the people seeking help, are making the task of helping them almost impossible.


A screen shot of a video game, with the question, “What is wrong with this,” is not very helpful.


If anyone is to help them, we require the brand and model of the television, we need a description of the fault, in their own words, and any other thing (noise/sound) that might help. If a screen shot, or short film clip, were to display a test pattern, so much could be checked.


About three Saturdays ago I was watching a DVD of the musical, South Pacific, and was amazed to see some early special effects that basically consisted of lowering one of primary colours to produce a coloured tints to the picture. Sometimes a different tint on the same scene (Island of Bali Hai) This is definitely not a movie to use when adjusting a set's grey-scale.]]> The above statement sounds quite obvious and reasonable.
I bring this up because I am seeing so very many requests for help on C.R.T. TV Repair forums where the people seeking help, are making the task of helping them almost impossible.


A screen shot of a video game, with the question, “What is wrong with this,” is not very helpful.


If anyone is to help them, we require the brand and model of the television, we need a description of the fault, in their own words, and any other thing (noise/sound) that might help. If a screen shot, or short film clip, were to display a test pattern, so much could be checked.


About three Saturdays ago I was watching a DVD of the musical, South Pacific, and was amazed to see some early special effects that basically consisted of lowering one of primary colours to produce a coloured tints to the picture. Sometimes a different tint on the same scene (Island of Bali Hai) This is definitely not a movie to use when adjusting a set's grey-scale.]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9508 Fri, 10 Oct 2025 06:52:55 +0000 ppppenguin]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9508 https://www.bbc.co.uk/historyofthebbc/re...nd-the-bbc talking about the 70th anniversary of experimental colour from Alexandra Palace. Technical details sounded about right. Audio clip from "Early one morning" where there is surviving cine film. Remember that this was before videotape.]]> https://www.bbc.co.uk/historyofthebbc/re...nd-the-bbc talking about the 70th anniversary of experimental colour from Alexandra Palace. Technical details sounded about right. Audio clip from "Early one morning" where there is surviving cine film. Remember that this was before videotape.]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9486 Fri, 22 Aug 2025 06:19:35 +0000 Desmond]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9486 Pye 12G-1 B&W Television. Chassis T25-4A


Hello all. My next attempted repair/restoration is the above listed set from around 1970. It was designed and made in Australia, and I am sure that I have never worked on another one any time in the past. This is because of the unusual cabinet. to service the set one removes the rear cover, but it is best to also remove the front of the cabinet as well.


I had this little set lying around for a few years before I finally had time to take a look at it. Now that I have retired, I no longer have to wait for a weekend to warm-up the soldering iron.


I started by reforming the electrolytic capacitors as best as I could, then cleaned out decades of dust. I wanted the set to look good whether it was to be a working set, or a display only set.


I cleaned the potentiometers, and measured the E.S.R. of the electrolytic caps. None were faulty. I then removed the tuner to clean the contacts and repair a broken feed through cap that couples the aerial lead to the internal balun. Because the channel knob had no channel markings on it, I set the tuner turret to the CH-1 position and and remounted the tuner marking the ch-1 position on the knob/cabinet. Next I removed the broken telescopic antennas, and glued some cracks in the cabinet.


Finally I powered up the set. I fed a signal to the set from a ch-1 modulator, and adjusted the controls to get a stable picture. The picture was alright but not great, My picture tube tester said that the control grid (No.1) was open circuit. Odd. the brightness and contrast control worked! Some type of electrostatic coupling? The black to white transitions look as though someone is holding the cathode lead. Low high frequency response.




The tuner's local oscillator seemed to be running a little low. I could not quite tune to sound bars. All the channels that I tried did not quite tune to sound bars.


At this point I decided to give up on this set. Too much wrong.

• Two broken telescopic antennas.
  
• Bad picture tube.
  
• Case damaged.
  
• Tuner alignment.
  
• Speaker open circuit.
  

By the way, I have many photographs of the items that I work on, but I do not have much luck uploading them.


If there is someone good at posting photos, I could e-mail some photos to them and let them select which and how many pics to post for each project.]]> Pye 12G-1 B&W Television. Chassis T25-4A


Hello all. My next attempted repair/restoration is the above listed set from around 1970. It was designed and made in Australia, and I am sure that I have never worked on another one any time in the past. This is because of the unusual cabinet. to service the set one removes the rear cover, but it is best to also remove the front of the cabinet as well.


I had this little set lying around for a few years before I finally had time to take a look at it. Now that I have retired, I no longer have to wait for a weekend to warm-up the soldering iron.


I started by reforming the electrolytic capacitors as best as I could, then cleaned out decades of dust. I wanted the set to look good whether it was to be a working set, or a display only set.


I cleaned the potentiometers, and measured the E.S.R. of the electrolytic caps. None were faulty. I then removed the tuner to clean the contacts and repair a broken feed through cap that couples the aerial lead to the internal balun. Because the channel knob had no channel markings on it, I set the tuner turret to the CH-1 position and and remounted the tuner marking the ch-1 position on the knob/cabinet. Next I removed the broken telescopic antennas, and glued some cracks in the cabinet.


Finally I powered up the set. I fed a signal to the set from a ch-1 modulator, and adjusted the controls to get a stable picture. The picture was alright but not great, My picture tube tester said that the control grid (No.1) was open circuit. Odd. the brightness and contrast control worked! Some type of electrostatic coupling? The black to white transitions look as though someone is holding the cathode lead. Low high frequency response.




The tuner's local oscillator seemed to be running a little low. I could not quite tune to sound bars. All the channels that I tried did not quite tune to sound bars.


At this point I decided to give up on this set. Too much wrong.

• Two broken telescopic antennas.
  
• Bad picture tube.
  
• Case damaged.
  
• Tuner alignment.
  
• Speaker open circuit.
  

By the way, I have many photographs of the items that I work on, but I do not have much luck uploading them.


If there is someone good at posting photos, I could e-mail some photos to them and let them select which and how many pics to post for each project.]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9478 Fri, 08 Aug 2025 06:11:24 +0000 Desmond]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9478 Hi Folks. That model number does look to have been created by a committee.

Oscar, 12” Black and White television. Model P12-H4A9


Years ago I received a schematic diagram for the above television, in a box of service data from a closed down TV repair shop. I had never seen nor heard of the brand Oscar, and therefore thought that I would never come across one. As stated elsewhere, I had supplied a copy of the schematic to another technician and thought no more about that model.


After finding and purchasing one at an auction a couple of weeks ago I decided to make its repair my next project. First I examined the set before tearing it apart. A warning label below the aerial terminals confirmed that it was intended for the Australian market. Its rarity in the market place makes me think that the importer only ever imported one container of these sets, possibly a minimum order of 500 units.


Since the last analogue transmissions ended in December of 2013 the set was likely un-powered for at least twelve years and probably many more.
So, I removed one of the compactatron valves to open circuit the heater chain. Then I was able to reform the main electos with the aid of my variac. Spoiler alert. The electro on the screen grid of the vertical output valve did go bang, after the set was brought up to operating value.


There was much fun to be had removing decades of dust from the interior of the set. I ended up replacing four of the seven electros. I cleaned the valve pins and sockets, Cleaned the tuner contacts with a business card and contact cleaner, and cleaned most of the pots. Last of all, I replaced the 1st sound I.F. transistor.


Finally, adjustments made it all well. I had forgotten how long it takes valves to fully warm up. It might be that the 33GY7 is a little weak, but I do not have one lying about.


That is enough fun for now. I will go back to working on my Philips
PM-5509 pattern generator, then onto a Pye 12G-1 television.]]> Hi Folks. That model number does look to have been created by a committee.

Oscar, 12” Black and White television. Model P12-H4A9


Years ago I received a schematic diagram for the above television, in a box of service data from a closed down TV repair shop. I had never seen nor heard of the brand Oscar, and therefore thought that I would never come across one. As stated elsewhere, I had supplied a copy of the schematic to another technician and thought no more about that model.


After finding and purchasing one at an auction a couple of weeks ago I decided to make its repair my next project. First I examined the set before tearing it apart. A warning label below the aerial terminals confirmed that it was intended for the Australian market. Its rarity in the market place makes me think that the importer only ever imported one container of these sets, possibly a minimum order of 500 units.


Since the last analogue transmissions ended in December of 2013 the set was likely un-powered for at least twelve years and probably many more.
So, I removed one of the compactatron valves to open circuit the heater chain. Then I was able to reform the main electos with the aid of my variac. Spoiler alert. The electro on the screen grid of the vertical output valve did go bang, after the set was brought up to operating value.


There was much fun to be had removing decades of dust from the interior of the set. I ended up replacing four of the seven electros. I cleaned the valve pins and sockets, Cleaned the tuner contacts with a business card and contact cleaner, and cleaned most of the pots. Last of all, I replaced the 1st sound I.F. transistor.


Finally, adjustments made it all well. I had forgotten how long it takes valves to fully warm up. It might be that the 33GY7 is a little weak, but I do not have one lying about.


That is enough fun for now. I will go back to working on my Philips
PM-5509 pattern generator, then onto a Pye 12G-1 television.]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9438 Mon, 21 Apr 2025 00:48:41 +0000 LENINGRAD T2]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9438 - The metal elements were blurred, I did not see any details 
- The glass near the anode socket has a longitudinal depression. The condition and length of the preserved metal fragment of the electrode are unknown 
- The thickness of the glass in the neck area is about 2 mm and is uniform 
- The thickness of the glass of the balloon is almost uniform and ranges from 4.46 mm to 5.08 mm 
- CRT balloon is made of two parts. The glass weld is very uniform, almost perfect throughout the entire circular course. It definitely protrudes into the CRT light 
- Tomography allows for tracing the layered structure of the glass of the entire CRT. I found only one air defect of 0.8x2 mm. I consider this an excellent production result 
- 3D reconstructions very realistically show the surface of the picture tube, the longitudinal depression in the area of the anode socket and the interior of the picture tube - you can take a tour of the interior of the picture tube 
To sum up, the CT scan very well illustrated the structure of the glass and the surface of the picture tube. I did not obtain any important information about the condition of the wire in the anode socket and the electron gun. 


  crt01.jpeg (Size: 827.25 KB / Downloads: 30)
  crt02.jpeg (Size: 760.07 KB / Downloads: 27)
  crt03.jpg (Size: 361.95 KB / Downloads: 32)
  crt04.jpg (Size: 148.66 KB / Downloads: 32)
  crt05.jpg (Size: 360.8 KB / Downloads: 33)
  crt06.jpg (Size: 157.84 KB / Downloads: 32)

A radiologist friend suggested taking a regular X-ray. This method revealed much more practical information: 
- The structure of the glass around the surviving fragment of the anode electrode is correct and thick enough to perform mechanical cleaning 
- An electron gun, including the cathode and heater areas, look correct with preserved continuity of the microwires 
- Emiscope inscription clearly visible in X-rays must have a lead admixture in its structure.


  Foto 01.jpg (Size: 768.46 KB / Downloads: 31)
  Foto 02.jpg (Size: 354.57 KB / Downloads: 30)
  Foto 03.jpg (Size: 610.48 KB / Downloads: 31)
  Foto 04.jpg (Size: 608.64 KB / Downloads: 30)

Now all that remains is to implement the CRT repair plan.

Adam.]]> - The metal elements were blurred, I did not see any details 
- The glass near the anode socket has a longitudinal depression. The condition and length of the preserved metal fragment of the electrode are unknown 
- The thickness of the glass in the neck area is about 2 mm and is uniform 
- The thickness of the glass of the balloon is almost uniform and ranges from 4.46 mm to 5.08 mm 
- CRT balloon is made of two parts. The glass weld is very uniform, almost perfect throughout the entire circular course. It definitely protrudes into the CRT light 
- Tomography allows for tracing the layered structure of the glass of the entire CRT. I found only one air defect of 0.8x2 mm. I consider this an excellent production result 
- 3D reconstructions very realistically show the surface of the picture tube, the longitudinal depression in the area of the anode socket and the interior of the picture tube - you can take a tour of the interior of the picture tube 
To sum up, the CT scan very well illustrated the structure of the glass and the surface of the picture tube. I did not obtain any important information about the condition of the wire in the anode socket and the electron gun. 


  crt01.jpeg (Size: 827.25 KB / Downloads: 30)
  crt02.jpeg (Size: 760.07 KB / Downloads: 27)
  crt03.jpg (Size: 361.95 KB / Downloads: 32)
  crt04.jpg (Size: 148.66 KB / Downloads: 32)
  crt05.jpg (Size: 360.8 KB / Downloads: 33)
  crt06.jpg (Size: 157.84 KB / Downloads: 32)

A radiologist friend suggested taking a regular X-ray. This method revealed much more practical information: 
- The structure of the glass around the surviving fragment of the anode electrode is correct and thick enough to perform mechanical cleaning 
- An electron gun, including the cathode and heater areas, look correct with preserved continuity of the microwires 
- Emiscope inscription clearly visible in X-rays must have a lead admixture in its structure.


  Foto 01.jpg (Size: 768.46 KB / Downloads: 31)
  Foto 02.jpg (Size: 354.57 KB / Downloads: 30)
  Foto 03.jpg (Size: 610.48 KB / Downloads: 31)
  Foto 04.jpg (Size: 608.64 KB / Downloads: 30)

Now all that remains is to implement the CRT repair plan.

Adam.]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9428 Tue, 25 Mar 2025 00:15:05 +0000 BVH2000]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9428
One of these was an (unidentified) fire brigade using CCTV & VTR to record and observe fires from a camera mounted on a Simon Snorkel lift.

I was intrigued by the clips of the VTR which wasn’t one I immediately recognised. It’s hard to make out in the rather grainy 16mm film but after a bit of searching I think it may be the “mythical beast” of industrial VTRs the Ikegami 2/3” tape width TVR-301 or 401
http://www.labguysworld.com/Cat_Ikegami.htm

Here’s a couple of frame grabs from the programme 


  IMG_0305.jpeg (Size: 229.1 KB / Downloads: 27)
  IMG_0306.jpeg (Size: 265.04 KB / Downloads: 27)
  IMG_0314.jpeg (Size: 269.01 KB / Downloads: 27)

The externally accessed locker mounting doesn’t strike me as a particularly hospitable environment for a reel to reel VTR.

Anybody else ever seen or come across one of these ?]]>
One of these was an (unidentified) fire brigade using CCTV & VTR to record and observe fires from a camera mounted on a Simon Snorkel lift.

I was intrigued by the clips of the VTR which wasn’t one I immediately recognised. It’s hard to make out in the rather grainy 16mm film but after a bit of searching I think it may be the “mythical beast” of industrial VTRs the Ikegami 2/3” tape width TVR-301 or 401
http://www.labguysworld.com/Cat_Ikegami.htm

Here’s a couple of frame grabs from the programme 


  IMG_0305.jpeg (Size: 229.1 KB / Downloads: 27)
  IMG_0306.jpeg (Size: 265.04 KB / Downloads: 27)
  IMG_0314.jpeg (Size: 269.01 KB / Downloads: 27)

The externally accessed locker mounting doesn’t strike me as a particularly hospitable environment for a reel to reel VTR.

Anybody else ever seen or come across one of these ?]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9394 Fri, 17 Jan 2025 14:17:12 +0000 Doodlebug]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9394 https://www.facebook.com/watch/?v=317461265565067]]> https://www.facebook.com/watch/?v=317461265565067]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9389 Tue, 07 Jan 2025 16:32:03 +0000 Exiled Yorkshireman]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9389
To take my mind off certain medical issues I've started to try to restore my first television, which is an Ultra V1770. I'm lacking experience and struggling somewhat. I appreciate that this set is not especially well thought of, but it's what I've got.

First step was to sort out the reservoir and smoothing caps, followed by waxies in the line and frame stages. I'm hoping to get a raster before moving on to the I/F and tuner.

The frame oscillator valve was missing and I've replaced it with a NOS one. The frame oscillator seems to be running OK albeit somewhat fast. 50Hz and below are only achievable by turning the frame hold control nearly to minimum.

The line oscillator runs, but a fair bit too fast. The line hold control operates, but the minimum stable frequency is about 6.7kHz. Any lower than this and it becomes unstable. I'm not currently (no pun intended) getting any EHT. I did for a couple of minutes, at which point even my hearing was able to detect a line whistle.  My homemade ring tester suggested that the LOPT is OK. The filament of the EHT rectifier is OK.

What should I check next?  Any help would be appreciated. I have a scope and diff probe which is good up to 750V, and all three service manuals (manufacturers, Trader and Radio Retailing)]]>
To take my mind off certain medical issues I've started to try to restore my first television, which is an Ultra V1770. I'm lacking experience and struggling somewhat. I appreciate that this set is not especially well thought of, but it's what I've got.

First step was to sort out the reservoir and smoothing caps, followed by waxies in the line and frame stages. I'm hoping to get a raster before moving on to the I/F and tuner.

The frame oscillator valve was missing and I've replaced it with a NOS one. The frame oscillator seems to be running OK albeit somewhat fast. 50Hz and below are only achievable by turning the frame hold control nearly to minimum.

The line oscillator runs, but a fair bit too fast. The line hold control operates, but the minimum stable frequency is about 6.7kHz. Any lower than this and it becomes unstable. I'm not currently (no pun intended) getting any EHT. I did for a couple of minutes, at which point even my hearing was able to detect a line whistle.  My homemade ring tester suggested that the LOPT is OK. The filament of the EHT rectifier is OK.

What should I check next?  Any help would be appreciated. I have a scope and diff probe which is good up to 750V, and all three service manuals (manufacturers, Trader and Radio Retailing)]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9343 Fri, 04 Oct 2024 15:22:19 +0000 Panrock]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9343
I'm starting a new constructional project - to make a 'portable' 90-line colour Mirror Screw.

If of interest, you can follow progress here:

Narrow-Bandwidth Television Association • View topic - A new 90-line Mirror Screw (taswegian.com)

Cheers,

Steve]]>
I'm starting a new constructional project - to make a 'portable' 90-line colour Mirror Screw.

If of interest, you can follow progress here:

Narrow-Bandwidth Television Association • View topic - A new 90-line Mirror Screw (taswegian.com)

Cheers,

Steve]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9342 Mon, 30 Sep 2024 20:40:19 +0000 ppppenguin]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9342
https://www.phoronix.com/news/Linux-6.11...ochrome-TV

I know people have been programming graphics cards for years to do odd TV standards. I've also seen a R-Pi converting a video source to 405. Does this represent anything really new?]]>
https://www.phoronix.com/news/Linux-6.11...ochrome-TV

I know people have been programming graphics cards for years to do odd TV standards. I've also seen a R-Pi converting a video source to 405. Does this represent anything really new?]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9323 Mon, 12 Aug 2024 13:57:50 +0000 sickdear]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9323 Has anyone ever used PM5515? Because this color pattern generator model is Philips PM5515. I remember that I wanted to buy this one before.

  888B3508-1563-4B60-9CFA-3DCCA6F0435E.jpeg (Size: 43.67 KB / Downloads: 21) ]]> Has anyone ever used PM5515? Because this color pattern generator model is Philips PM5515. I remember that I wanted to buy this one before.

  888B3508-1563-4B60-9CFA-3DCCA6F0435E.jpeg (Size: 43.67 KB / Downloads: 21) ]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9307 Mon, 22 Jul 2024 06:08:13 +0000 sickdear]]> https://golbornevintageradio.co.uk/forum/showthread.php?tid=9307
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