24th Jul 2015, 11:30 am | #21 |
Nonode
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 2,495
|
Re: Very rusty ViewMaster TV
Thank you Fernseh - you have prompted a memory of a company in Malvern that made a living out of re-gunning CRTs (and dispatching them via the railway). I always wondered why people did that - now I think I know the answer.
I presume that if your TV was used locally for you then it is tuned for Channel B5 from Pontop Pike. |
24th Jul 2015, 12:20 pm | #22 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Very rusty ViewMaster TV
Hi Steve,
I'm going to separate the RF unit from the timebase unit. Doing this will assist the re-rusting procedure. Also, this action will make the testing of the RF unit easier, I'll use a bench power supply for that. The set was originally bought and used in Bradford so it's likely to be fix tuned to the Holm Moss channel B2 transmitter. It might be possible to retune it to channel B1. DFWB. |
24th Jul 2015, 12:33 pm | #23 |
Nonode
Join Date: Jun 2009
Location: Herefordshire, UK.
Posts: 2,495
|
Re: Very rusty ViewMaster TV
Right, I imagine a retune to Channel B1 should not be a problem - I bet thousands of the sets were used in the Ally Pally service area...
|
24th Jul 2015, 12:39 pm | #24 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Very rusty ViewMaster TV
30,000 ViewMaster kits sold.
DFWB. |
25th Jul 2015, 10:54 am | #25 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
|
Re: Very rusty ViewMaster TV
Indeed, that was a nationwide number. It was available for use in all television areas. The original model was designed for AP but as the transmitters opened, details became available and modifications published to suit.
This model came from Brighton and received the channel 3 Truleigh Hill relay station that came on air around 1952 in time for the Coronation. It was certainly a big seller with valve and CRT manufacturers taking full page adverts in various technical journals stating that their products were suitable for the 'View Master'. There were of course other very good designs from the F.J. Camm stable including the 'PT Television receiver' from 1949 slightly earlier than the VM. I have one of these rescued from the South Coast and when I have time....Regards, John. |
28th Jul 2015, 5:28 pm | #26 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Very rusty ViewMaster TV
Work continues on the ViewMaster chassis. The two sections have been separated, this will make the de-rusting procedure easier. The timebase is the easy one, nearly all the components can be removed to assist the clean up job.
The RF chassis is not going to be as easy however, this unit must have taxed the skills of the home constructor. Meanwhile, we've had heavy rain falls here in the North-East and this will help the "seasoning" of the plywood sheet which will be used to make John's ViewMaster cabinet. DFWB. |
28th Jul 2015, 6:35 pm | #27 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
|
Re: Very rusty ViewMaster TV
That tin of 'COLRON' French polish David, I feel it's a little premature. I don't want to see any nail heads in my bespoke cabinet...John.
|
9th Sep 2015, 10:13 pm | #28 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Very rusty ViewMaster TV
This evening I decided to make a start on the RF unit. The TCC (Telegraph Condenser Company) was the main supplier of capacitors to the ViewMaster home construction TV project. I've checked all the capacitors present in the RF unit and except for the mica and ceramic dielectric capacitors all the others are useless. The metal case "Picopack" electrolytics and "Metalmite" paper capacitors have serious leaks. You like the names?
I haven't checked the timebase components but I reckon it'll be much the same for those as well. DFWB. |
11th Nov 2015, 2:04 pm | #29 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Very rusty ViewMaster TV
There is no doubt the View Master is a cleverly designed TV receiver.
There is a lot of subtle circuit design features worthy of comment. The line output stage for example. Here we see that a proper efficiency diode employed. Recovered energy from the flyback produces the boosted HT for the first anode of tetrode CRTs. More importantly the reclaimed energy can provide the first part of the line scan. The redrawn circuit shows the efficiency diode MR2 in a clearer manner. C42 is the boost capacitor. The designer chose a metal rectifier instead of a thermionic valve. DFWB. |
11th Nov 2015, 5:01 pm | #30 | |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,198
|
Re: Very rusty ViewMaster TV
Quote:
I've always wondered just who were the clever designers of these kits. They generally worked rather well, despite being assembled and tested under totally uncontrolled production conditions on hobbyists' kitchen tables! Does anyone know any designers' names? Were they moonlighting from their day jobs in high tech industry? Martin
__________________
BVWS Member |
|
11th Nov 2015, 6:15 pm | #31 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Very rusty ViewMaster TV
Hi Martin,
We do know the name of the View Master designer. He was Mr W. I. Flack FTS and I believe he worked for the TCC condenser company. Confirmation of that fact needed. I think it always a good idea to discover who designed something, whatever it is, be it Radio TVs cars etc. DFWB. |
12th Nov 2015, 10:46 am | #32 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Very rusty ViewMaster TV
When the boost capacitor C42 and the diode MR2 are repositioned in the circuit as shown in the second attachment it can be seen that the circuit resembles the line timebase practise that was the norm up to the end of the valve era.
The design of the line output transformer can be simplified because the main winding can be wound as an auto transformer. DFWB. Last edited by FERNSEH; 12th Nov 2015 at 10:52 am. |
12th Nov 2015, 11:58 am | #33 | |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,198
|
Re: Very rusty ViewMaster TV
Quote:
I guess the commercial incentive was the promotion of TCC capacitors, but the end achievement was so much greater than that original objective! Martin
__________________
BVWS Member |
|
12th Nov 2015, 12:28 pm | #34 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Very rusty ViewMaster TV
There are other clever circuit features which we'll discuss later as the restoration progresses.
With over 30,000 ViewMaster kits sold the industry did very well out of this project. The only loser of course was the taxman, no money for him because kits of parts did not attract purchase tax. If you think about that'll be over 60,000 Mazda 6K25 thyratrons and 120,000 Mullard EF50 pentodes used in the sets I'm sure the valve manufactures were very pleased with the ViewMaster as well. DFWB. |
12th Nov 2015, 1:40 pm | #35 | |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
|
Re: Very rusty ViewMaster TV
Quote:
(I am aware that there was lobbying by some parts of the electronics industry in the immediate-post-WWII era to have stocks of government-surplus equipment/parts destroyed rather than released on to the market, because of the fear that this surplus stock would knock the bottom out of the market for new production. Valves were released from MoS stores to the valve-distributors in controlled 'lots' over several years - along with permission to rebrand them - to mitigate this). |
|
12th Nov 2015, 2:17 pm | #36 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
Re: Very rusty ViewMaster TV
I think are you right about those EF50s. Looking at the all the Mullard EF50s in the ViewMaster and I find they are almost certainly WW2 surplus stock. One example is marked A crown M and is like all the others in this set, made in the USA. Likely to have been made by Sylvania.
Yes, your right those red EF50s would have done the valve manufacturing industry no favours but saying that many TV manufactures were using WW2 surplus EF50s. All the other valves in the set are of current production including the 6K25 which was introduced in 1949. http://www.radiomuseum.org/tubes/tube_6k25.html DFWB. |
12th Nov 2015, 5:54 pm | #37 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,643
|
Re: Very rusty ViewMaster TV
Surplus valves may not have helped the industry, but the shot in the arm for TV viewing possibly did in the long run. Receivers were extremely expensive in the early days.
|
12th Nov 2015, 6:39 pm | #38 |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,198
|
Re: Very rusty ViewMaster TV
Ex-WD kit, including those affordable surplus valves, also made it possible for many of us youngsters to take up electronics as an enjoyable hobby, later leading to an interesting career.
Martin
__________________
BVWS Member |
12th Nov 2015, 9:04 pm | #39 |
Rest in Peace
Join Date: Jun 2004
Location: Burghfield, Reading, Berkshire, UK,
Posts: 1,055
|
Re: Very rusty ViewMaster TV
I heard that many hundreds of tons of surplus WWII electronic equipment was dumped out at sea just to keep the electronics industry afloat. One can imagine what effect the many thousands of components and valves flooding the market would have had. The numbers that were released were tightly controlled.
|
26th Mar 2018, 10:14 pm | #40 |
Dekatron
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
|
ViewMaster TV restoration.
I've decided to remove all the components from the timebase chassis. The metalwork will be de-rusted, primed and painted metallic grey.
Fortunately, most of the screws are brass so there was no problems removing the chassis components, only the screws attaching the preset controls are proving difficult to remove. Note the boost diode, it's a selenium rectifier. Designated as MR2 in the circuit diagram. Westinghouse type 14-D-36. DFWB. Last edited by Station X; 26th Apr 2018 at 9:57 am. Reason: Threads merged. |