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View Poll Results: Which TV should The Queens' Christmas Speech be watched on
KB 24' Regina 8 57.14%
Philips 19TG108U 1 7.14%
None of the above. 5 35.71%
Voters: 14. You may not vote on this poll

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Old 23rd Oct 2021, 8:46 pm   #41
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Default Re: TV to watch Queen's Christmas Speech on?

The poll has closed. Turnout was abysmal, but the KB 24' Regina emerged as a clear winner.
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Old 23rd Oct 2021, 8:47 pm   #42
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Default Re: TV to watch Queen's Christmas Speech on?

Quote:
Originally Posted by Station X View Post
The poll has closed. Turnout was abysmal, but the KB 24' Regina emerged as a clear winner.
Hi Graham glad the KB won & I agree about the turn out
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Old 23rd Oct 2021, 8:51 pm   #43
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Quote:
Originally Posted by FERNSEH View Post
Hi Bob,
after many years using all sorts of horrible soldering irons, including some expensive ones I'm back to using the Weller soldering station again.

DFWB.
Had a horrible soldering station from Maplin soldering tips were US despite being CE marked it would wipe out MW.
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Old 23rd Oct 2021, 8:54 pm   #44
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Default Re: TV to watch Queen's Christmas Speech on?

Can the Philips 19TG108U be reintroduced in a separate topic or a continuation of the 2011 topic? The recent BRC 1500 jellypot line transformer substitution in a Stella ST1011U was a success so there is no reason the same can't be done to the electrically similar 19" set.

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Old 23rd Oct 2021, 8:58 pm   #45
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Default Re: TV to watch Queen's Christmas Speech on?

Just for you David the original thread is open.

https://www.vintage-radio.net/forum/...09#post1416909

Cheers

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Old 23rd Oct 2021, 10:22 pm   #46
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Default Re: TV to watch Queen's Christmas Speech on?

Hi Mike,
many thanks for reintroducing the topic. The Philips will brought down from the upstairs storeroom on Monday.
Meanwhile work will continue on the KB PV100. My attention will be drawn to the cabinet. Still got plenty time to finish off the restoration.

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Old 23rd Oct 2021, 10:45 pm   #47
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Default Re: TV to watch Queen's Christmas Speech on?

Hi.
Well I've just been given an HMV 1807 for a possible donor set for parts to get a Marconiphone console version going. I'm hoping that I can get both working. The 1807 has a mint cabinet but the CRT has a shorted heater. So will I get both fixed with the 1807 ready for the queen's speech 2021? Will have to see.
Any offers for a spare CRT?
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Old 24th Oct 2021, 11:26 am   #48
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Default Re: TV to watch Queen's Christmas Speech on?

Hi Trevor,

I've got a 3/16 with a heater that lights and no sign of a whitewashed getter. I don't think I was able to get any emission but you are welcome to try and see if you can get it to work.

Peter
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Old 24th Oct 2021, 8:35 pm   #49
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Default Re: TV to watch Queen's Christmas Speech on?

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Hi Trevor,

I've got a 3/16 with a heater that lights and no sign of a whitewashed getter. I don't think I was able to get any emission but you are welcome to try and see if you can get it to work.

Peter
Brilliant.
I'll call you tomorrow.
Many thanks.
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Old 24th Oct 2021, 8:59 pm   #50
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Old 25th Oct 2021, 9:12 pm   #51
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Quote:
Originally Posted by FERNSEH View Post
Results from todays capacitor changing session in the frame timebase.
Good linearity and plenty height adjustment. The pictures don't show it, but the interlace is perfect. With use the CRT is becoming really bright.
The seven waxies are from the frame timebase and the black Hunts Moldseal was the sync separator coupling capacitor
The 18Kohm resistor was the line output valve screen feed resistor.
Vision AGC performance is poor, having to use the sensitivity control to adjust the contrast. Likely the AGC decoupling capacitors are leaky. Vision AGC can be improved by replacing the 6BW7 common sound and vision IF amplifier with a Brimar 9D7 vari-mu pentode. However, the difficult to locate and insert 6BW7 is in position and it can remain there.

DFWB.
Glasnost ( openness ) was in Davids shop this afternoon and the KB was performing very well good bright picture at 12.5 KV but after 15 minutes the voltage went down to 5KV and no picture & the LOPT over wind was getting hot looks like its going to be a Tripler conversion pictures will follow showing the big Brimar 50CD6G line-output valve as well
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Old 25th Oct 2021, 10:12 pm   #52
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Default Re: TV to watch Queen's Christmas Speech on?

Some pictures as promised ( Thanks to Cobaltblue fo keeping me right )
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Old 25th Oct 2021, 10:24 pm   #53
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2 more pictures
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Old 26th Oct 2021, 11:50 am   #54
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Default Re: TV to watch Queen's Christmas Speech on?

Last night the EHT overwind became too hot to touch.
Today, the peak voltage on the anode of the 50CD6G line output will be measured to assess if it is viable to use a tripler unit in lieu of the overwind. Pulse must be at least 5KV.
The HT smoothing capacitor should really be replaced, but the CRT must be removed to do this. If the tube has to come out then it might be wise to replace the selenium HT rectifier.
Might consider replacing the 6BW6 common vision and sound IF amplifier valve with the vari-mu Brimar 9D7.
https://www.radiomuseum.org/tubes/tube_9d7.html

DFWB.
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Old 26th Oct 2021, 8:42 pm   #55
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Default Re: TV to watch Queen's Christmas Speech on?

Picture of the bulging HT capacitor.
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Old 28th Oct 2021, 9:02 pm   #56
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Default Re: TV to watch Queen's Christmas Speech on?

Things are not going well for the big KB. From last weeks 15.5KV from the line output transformer the EHT has now fallen to 10KV after warm-up and even that figure doesn't last too long before the picture disappears.

DFWB.
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Old 11th Nov 2021, 12:38 pm   #57
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Default Re: TV to watch Queen's Christmas Speech on?

Yesterday, to measure the peak voltage at the anode of the line output valve a high voltage silicon diode was connected to that point along with a 2200pF capacitor between the diode's cathode and chassis.
After warm-up the reading on the RBM EHT meter is slightly over 5KV and that's with the line output stage not operating at full efficiency.
After ten minutes the picture started to fade but the peak volts at the anode of the 50CD6G remained constant for a further five minutes and in due course began to fall to about 4.5KV.
Considering the CRT displays a very bright picture with an EHT of 15KV the possibility of employing a tripler to produce the EHT would be entirely valid.

DFWB.
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Old 11th Nov 2021, 10:47 pm   #58
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Today, a tripler was connected up to the anode of the line output valve. Excellent results, a full 15KV for the final anode of the CRT. The picture, albeit only the test card is very bright, far brighter than would have I expected from a very large CRT operating from a modest EHT voltage.
The bright picture remains on the screen for more than fifteen minutes but eventually the picture becomes narrower and the EHT voltage falls to about 12KV.
So now I have to decide to what action to do with the line output transformer.
Take a chance and remove the EHT winding hoping that it isn't the primary windings which are faulty?
The tripler has the look of one made for the BRC 3000 CTV.

DFWB.
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Old 12th Nov 2021, 6:10 pm   #59
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Default Re: TV to watch Queen's Christmas Speech on?

Hi.
I've now started on the HMV 2807 (not an 1807 as previously stated) a new thread has been started on the restoration. So who will win the challenge?
Bob are you donating a DAC90 as a prize?

PS Fernseh has a good head start though.
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Old 12th Nov 2021, 6:24 pm   #60
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Default Re: TV to watch Queen's Christmas Speech on?

Hi David good luck with the EHT winding
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