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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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4th Jun 2020, 7:50 pm | #61 |
Dekatron
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Re: The Ever-Ready experimental transistor TV set.
"and a very modern square display area,"
Possibly developed from a camera viewfinder tube? 7:45pm: the set has been switched for an hour and a half, the battery voltage is down to 8.16V and yet the internal power supply is delivering 11.86volts! DFWB. |
4th Jun 2020, 9:36 pm | #62 |
Heptode
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Re: The Ever-Ready experimental transistor TV set.
So it would be safe to say that the AA's would last at least 4hours, whichbis fairly impressive. I have a small casio LCD tv here which only does that.
Very interesting to think there could be another one of these knocking about too. |
6th Jun 2020, 10:36 am | #63 |
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Re: The Ever-Ready experimental transistor TV set.
linescan87 wrote: "So it would be safe to say that the AA's would last at least 4hours, which is fairly impressive. I have a small casio LCD tv here which only does that.
Very interesting to think there could be another one of these knocking about too." Hi John Joe, Just after four hours use the AA cells finally failed, reached a point in time when the terminal voltage of the battery suddenly went down to 3volts. Cells were very warm. Eight years before the Ever-Ready TV was made Ekco made the cleverly designed model TMB272 mains-battery TV set. But this set needed something like a car battery to supply the power as the current demand was 8 amps! DFWB. |
6th Jun 2020, 12:56 pm | #64 |
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Re: The Ever-Ready experimental transistor TV set.
“Nothing is so discouraging to an actor than to have to work for long hours upon hours in brightly lighted interior sets.” – John Wayne
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8th Jun 2020, 8:05 am | #65 |
Heptode
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Re: The Ever-Ready experimental transistor TV set.
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8th Jun 2020, 12:51 pm | #66 |
Heptode
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Re: The Ever-Ready experimental transistor TV set.
I wonder would a pack of D size alkaline fit in the battery compartment and how long they would last.
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9th Jun 2020, 11:27 am | #67 | |
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Re: The Ever-Ready experimental transistor TV set.
Quote:
I'll try out eight alkaline D cells later this week. A fault still exists in the line blanking pulse (first attachment) which can be corrected by fitting a 10Kohm resistor between the base and emitter of the line blanking transistor. DFWB. |
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30th Jun 2020, 9:14 am | #68 |
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Re: The Ever-Ready experimental transistor TV set.
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4th Jul 2020, 2:24 pm | #69 |
Pentode
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Re: The Ever-Ready experimental transistor TV set.
Hi All I just found this in a wireless & electrical trader for 22/08/1964.
Keith |
4th Jul 2020, 5:51 pm | #70 |
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Re: The Ever-Ready experimental transistor TV set.
Hi Keith,
it's a pity this set or something like didn't go into full production, the low power consumption would have been a sure selling point. Possibly the cost of making this kind of set? Still got one fault to sort out. The picture rolls on switch-on, this can be easily corrected with the frame hold control but after a few minutes frame sync is lost and the set remains in that condition for up to three minutes. Then the timebase oscillator assumes a lower frequency necessitating readjustment of the hold control again. After resetting the hold control the set will remain stable for as long as one would want the set to remain in use. Suspect components were the oscillator transistor and the two 1microfard timing capacitors, now replaced. I'm thinking about those Lucas diodes in the frame oscillator DFWB. |
5th Jul 2020, 9:15 am | #71 |
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Re: The Ever-Ready experimental transistor TV set.
I think there may be a ground tap part way along the green/red secondary winding, or else the -35 and +8v supplies would not be partitioned stably. They would be forced to take identical current and share the total voltage however it balanced.
I suspect a tap may be included in the purple wire connection to chassis. David
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5th Jul 2020, 10:32 am | #72 |
Dekatron
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Re: The Ever-Ready experimental transistor TV set.
"I suspect a tap may be included in the purple wire connection to chassis."
Hi David, Absolutely correct, in fact the power supply circuit has been amended to incorporate a tap on the secondary winding. There would be no way the circuit would work without it. Also, the polarity of the 6.2volt Zener diode was reversed. It's safe to say that the 10uF slow start capacitor was added to protect the OC35 power supply transistor. Because high value smoothing capacitors are employed the in-rush current was destroying the transistor. DFWB. |