TV Ambassador TV2

[LENINGRAD T2]

In some respects the line timebase circuit in the Ambassador TV2 resembles the Murphy V136.  The forward part of the scan is a result of the increase of current in transformer winding L31, this being a negative going sawtooth waveform. At the end of the forward scan the sudden change in current initiates the flyback pulse, this being a function of di/dt. The ringing effect at the end of the flyback is surprisingly well damped.  Seems the designer got away without using a damper diode.
It would be interesting to monitor the waveform present on the screen grid of the 20P1.

Geordie McBoyne.

It's quite amazing that two simple vertical and horizontal deflection circuits can get quite stable image and produce optimal EHT for CRT.
Baird T163 also has many analogies to Ambassador TV2, apart from Murphy V136.
I added RC elements to the scanning coils in parallel, which did not change the linearity, only the size of the image.
I've attached an image from the G2
   

[LENINGRAD T2]

Interesting Adam
I wonder why the effects continued with the smaller value, need to switch on my brain later on today.
Good work.

I reconnected C2 with a value of 100pF, which is 10x lower than the factory one, and the P1 potentiometer /1K/ identical to the factory one. As a result, horizontal synchronization improved stability significantly. At a small value of 100pF, the curl on the left side of the screen did not appear /at 150pF and above it was/. Interestingly, after changing C2 from 1nF to 100 pF, the P1 adjustment does not cause any image changes. In principle, P1 can be removed. I think the inclusion of C2 and P1 by the design engineers was a good move, but the circuit was not perfected. A potentiometer is fitted, not a fixed value resistor, which proves the instability of this solution.

[LENINGRAD T2]

Spotted in an early 1950 Wireless World. 

There were two knobs in January and three in October. Interesting.
       

[LENINGRAD T2]

It looks pretty good now. Likely watchable.

Now a little better . Final version.

   

[Murphyv310]

Very nice results Adam. Indeed well worth the the time and effort put into the set.
I've never seen in the flesh but I did have a later model that Frank Cuffe has now.

[Mike Watterson]

Brilliant.
I'm sure most of the 405 only sets I did in 1970-71 were poorer, though I was a pretty inexperienced kid then.

[LENINGRAD T2]

Finally, some cosmetics. I prepared knobs for potentiometers located on the back of the receiver in 3D printing technology - I had to replace them. An additional collar covers the shiny fixing screw. The size of the knobs is slightly larger than the original to mount it on a larger axis. After screwing into the laminate, the effect is quite good.

       

[Murphyv310]

Hi
I've been considering a 3D printer for a while, the only thing is I've no idea about graphics or art. No doubt any knob I made would be square or the dimensions would be totally wrong.
That's a great job of making the knob Adam.

[LENINGRAD T2]

The average home user is able to design simple items and print them themselves. Most people cannot pass this level. Knobs for televisions or radios are a more complex form. Their design requires the ability to work with 3D graphic applications. Home users usually print items designed by someone else online, such as game figurines. It should be noted that 3D printing is developing very strongly in professional applications, but not in home. I personally printed knobs, speaker frames, cups for CRT neck, big rubber collar for CRT, black bushings to hide modern capacitors, transformer elements, rubber feet, various types of plugs, emblems. Elements that are very difficult to design due to their shape can be scanned in 3D technology and printed. Resin is increasingly being used as a printing material. She has good mechanical properties. Elements printed in this technology are smooth.
By the way, I have a friend who is interested in old cars. He designs and prints details for old Jaguar models.
Trevor, I encourage you to buy a 3D printer. It's fun. If you run out of glasses for guests, you can quickly print them. Each with their own name