Re: Baird Garrick
 

Who designed these sets, was it Bush?

Peter

Re: Baird Garrick
 

Nothing to do with Bush Radio although some design elements of the T5 were incorporated in the Theatreland models. Most notable is the frame scanning system which employ extended pole pieces from the oscillator transformer.
There is evidence that the first Ambassador TVs used some of the technology from the Theatreland Baird sets.
Wasn't the post-war Baird TV manufacturing financed by J.L.Baird's friend Jack Buchanan? http://www.bairdtelevision.com/Buchanan.html

DFWB.

Re: Baird Garrick
 

Thanks for the info Andy.

Shouldn't that read "very few of the owners survived"? :laugh2:

Steve

Re: Baird Garrick
 

Hi Peter,
well as Fernseh points out obviously not Bush, but then again Bush must get some credit as most of the design is lifted from the pre-war Baird T18. The timebase has seen the simple change from B5 Cossor 41MP output triodes to Mazda octal PEN46 pentodes which are triode connected. Similar changes are found elsewhere in the set, but the design is really the television part of a T18 with updated valves. The only new parts of the design are the RF stages.
Anyway, I have no clue as to who updated the design and re-designed the sound and vision RF stages.

I've included a picture of the scanning yoke from the T18 so you can compare it with the photo in my last post. I should measure the coil resistance values and check them against the T18 manual.

Cheers
Andy

Re: Baird Garrick
 

Thanks David and Andy,

Yes, thumbing through Baird's biography co-authored by Malcolm Baird it looks as if in July 1944 Baird wrote to Buchanan with a view to setting up "John Logie Baird Ltd" along with his lawyer Shelley for the manufacture of television receivers and also cinema television.

In terms of receivers, their first was the giant Grosvenor of which only one was ever made and it appeared in early 1946. It looks as if the 27" CRT was an in house product but Plessey provided the television chassis, radiogram and cabinet.

After Baird's death and under Buchanan's chairmanship the theatreland models were apparently built at a factory in Rayner's Lane, Harrow and the Grosvenor was intended to be the top of the line model.

Peter

Re: Baird Garrick
 

A similar frame timebase circuit was used in the Ambassador TV2. See post #14. It would be interesting to find out which company designed the frame timebase. The original Baird company had links with Fernseh AG.

https://en.wikipedia.org/wiki/Fernseh

DFWB.

Re: Baird Garrick
 

I see a reference to a Baird Patented vertical deflection here:
https://www.earlytelevision.org/fernseh.html

I've emailed Darius asking if he knows the patent number.

Peter

Re: Baird Garrick
 

I've had a look through a stack (180) of Baird patents but I can't find it and unfortunately Darius can't locate it either.

In the biography there is a reference to "Baird's former assistant Anderson, who had continued with the company as technical partner, was asked to develop a table-top television set for the American standards."

The name EDWARD GEORGE ORME ANDERSON does appear in some of the Baird patents so he may have been the circuit designer of the "vertical deflection" circuit.

Peter

Re: Baird Garrick
 

From google patents, an amplifier attributed to Edward George Orme Anderson.
https://patents.google.com/patent/US2537807

Patent filed 1951 as a phase splitting amplifier. But this amplifier which employed the Mullard TSE4 secondary emission valve was used in this application in 1938 in the Baird T20 and T23 TV receivers.

DFWB.

Re: Baird Garrick
 

There are lots of Baird patents from the mechanical era and I didn't inspect many from the early 1930s but I think I looked at most of the mid 30s onwards. I did come across the video amp one but nothing that looked like a vertical deflection circuit. I am skeptical about JLB being a circuit designer. I was just clutching at straws with Anderson in my ignorance of any other obvious name. I did try looking at Geoffrey George Bernard, A. G. D. West, Paul Vernon Reveley, Alfred Sommer apart from JLB himself without success.

Peter

Re: Baird Garrick
 

I wonder if it might be Rudolf Jan Hamilton Forman?
https://worldwide.espacenet.com/publ...=&locale=en_EP

Peter

Re: Baird Garrick
 

Hi Peter,
you might be on to something. However this patent is about line deflection. Note that it mentions 6kHz which is 25Hz x 240 lines. It could well be the same person who designed the frame deflection as well though.

Cheers
Andy

Re: Baird Garrick
 

Hi Andy,

There is some similarity.

Peter

Re: Baird Garrick
 

Also:

https://worldwide.espacenet.com/publ...FT=D&DB=EPODOC

https://worldwide.espacenet.com/publ...FT=D&DB=EPODOC

https://worldwide.espacenet.com/publ...FT=D&DB=EPODOC

https://worldwide.espacenet.com/publ...C&locale=en_EP

Re: Baird Garrick
 

From the Baird Television website. About Jan Forman:

http://bairdtelevision.com/forman.html

DFWB.

Re: Baird Garrick
 

I think this is the patent that describes the combined frame oscillator transformer and scan coil.

https://worldwide.espacenet.com/publ...C&locale=en_EP

There are also some further patents from George Richard Tingley relating to the front scanned CRT used in the 27" Grosvenor and the 11" front scanned projection tubes.

https://worldwide.espacenet.com/publ...C&locale=en_EP

Peter

Re: Baird Garrick
 

Hi Peter,
That looks like the frame scanning patent we're looking for although the text doesn't mention anything about the pole extension pole pieces.

The text does mention extra the winding on the transformer used to counter the standing valve anode current. Without this winding the picture will be deflected off the screen.

The Murphy V136 of 1948 employed a self oscillating frame timebase. In this receiver the frame oscillator transformer is also the scanning yoke.

That projection CRT used in the Grosvenor set is an interesting device. Some provision for keystone correction of the raster will be necessary.

DFWB.

Re: Baird Garrick
 

Hi David,

Perhaps Tingley thought it unnecessary to show the pole piece configuration because anyone using the GB463972 description would be forced to use extended pole pieces anyway. The other Tingley patents I mentioned do show extended poles in their figures.

As I understand it there were two televisions showing the 1946 victory parade in the Savoy. One had a 5' projection display that magnified the image from an 11" front scanned CRT and the other was the "Grosvenor" which had a 27¾" front scanned CRT viewed directly. I think there was talk of using the "Grosvenor" CRT for larger projections but that probably got overtaken by the "Teapot" projection CRTs.

Peter

Re: Baird Garrick
 

As Peter says, look at page 5 of the above patent. It clearly shows the extended pole pieces

Peter, How do you find all this stuff?

Cheers
Andy

Re: Baird Garrick
 

Hi Andy,

Nothing clever I'm afraid. Just searching in Espacenet for any likely inventor names and sometimes one leads to another. "John Logie Baird: A Life" also gave a few starting points.

Thanks for the page 5. I missed that.

Peter