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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Aug Fri 16, 2019 5:37 pm 
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Joined: Feb Wed 03, 2016 9:11 pm
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Location: Savannah, GA
Those BK 1077B's seem to be pretty affordable. What are the chances of them needed calibration after purchase as most being sold on eBay are "untested"?


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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Aug Fri 16, 2019 7:10 pm 
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Joined: May Thu 14, 2015 4:15 pm
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Location: Dallas, TX
FYI.
B&K made a series of similar models through the years. The first version was just called Dynascan, then models 1075, 1076, 1077 and 1077B. The earliest are all tube bases while the last is mostly solid state.
I have a 1075 that I will restore some day, I did repaint the case. Even the newest version is probably old enough to need the electrolytics replaced at the minimum.
Do a search on the forum here and at Videokarma on the units.

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It's not the Destination, It's the Journey.


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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Aug Fri 16, 2019 7:35 pm 
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Joined: Jan Thu 01, 1970 1:00 am
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Location: Woodinville, WA USA
I replaced the electrolytic on my 1077B and made a couple of basic adjustments such as centering the image.

Regards,

Phil Nelson
Phil’s Old Radios
https://antiqueradio.org/index.html


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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Aug Fri 16, 2019 7:46 pm 
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Joined: Nov Thu 11, 2010 6:03 pm
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Location: Pewaukee, WI
Personally if I prefer electronic test pattern generators for setting linearity, centering, convergence and the like. I also have made a test pattern DVD for when I want to broadcast a pattern to one or more sets and not have to lug a spaghetti box around.

The Analysts use a flying spot scanner that while it can be set up to be accurate is fundamentally less stable as well as heavier and bulkier than other devices. They shine in all different types of hard troubleshooting that you are going to do on your workbench, but lack that " bring it to any set anywhere in the house" mobility of a dedicated solid state pattern generator.


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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Aug Sat 17, 2019 1:08 am 
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Joined: Aug Thu 12, 2010 6:25 pm
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Location: Durham, NC
Electronic Memory wrote:
Personally if I prefer electronic test pattern generators for setting linearity, centering, convergence and the like. I also have made a test pattern DVD for when I want to broadcast a pattern to one or more sets and not have to lug a spaghetti box around.

The Analysts use a flying spot scanner that while it can be set up to be accurate is fundamentally less stable as well as heavier and bulkier than other devices. They shine in all different types of hard troubleshooting that you are going to do on your workbench, but lack that " bring it to any set anywhere in the house" mobility of a dedicated solid state pattern generator.


Yes, they are monumentally heavy! But cool.

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A collector of TV signal boosters and UHF converters -- God help me!
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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Nov Sat 16, 2019 9:48 pm 
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Joined: Feb Wed 03, 2016 9:11 pm
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Location: Savannah, GA
Good afternoon all, this set has been finished and been in use for a few months now, and this morning upon powering it up I was met with an empty screen. I was watching it last night for several hours without any issues. Despite the empty screen audio was coming through just fine, high voltage was present, and the ion trap was properly adjusted. Nothing had been changed since last night. After I checked the H.V. and ion trap I removed the chassis. I tried swapping each of the H.V. and horizontal section tubes, checked the flyback, and B+. I then noticed that I can get a partial picture with the brightness control adjusted to about 12 o' clock, but if I move the control either way from that position the picture disappears. At this point I removed the brightness control to clean and test it. It tested fine. I am stumped. It certainly seems that it could be the brightness control at fault, but it measured just fine.


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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Nov Mon 18, 2019 5:02 am 
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Joined: Nov Thu 11, 2010 6:03 pm
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Location: Pewaukee, WI
Check bias at the CRT base while varying the control and also measure HV while adjusting the control HV voltage should not vary from schematic value more than 2KV.


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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Nov Thu 21, 2019 9:10 pm 
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Joined: Feb Wed 03, 2016 9:11 pm
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Location: Savannah, GA
I am not familiar with checking the bias on a CRT. How would I go about this?


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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Nov Thu 21, 2019 10:20 pm 
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Location: Pewaukee, WI
The schematic should list cathode and grid voltage with reference to the chassis compare measurements to schematic values and look for anomalies. It may also be helpful to measure cathode-grid voltage difference...The grid should be negative relative to the Cathode but not too negative and you should be able to approach a 0V difference between the two.


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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Dec Fri 13, 2019 4:27 pm 
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Joined: Feb Wed 03, 2016 9:11 pm
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Location: Savannah, GA
The grid looks to be the suspect here. It is running about 120V lower than the schematic value, and does not vary with the adjustment of controls. Possible causes?


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 Post subject: Re: Getting started on Admiral 19F1
PostPosted: Dec Sat 14, 2019 12:14 am 
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Joined: Aug Thu 12, 2010 6:25 pm
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Location: Durham, NC
The grid (pin 2 of the CRT) shouldn't change with any control setting - it's only supplying a vertical pulse for blanking. The brightness control should vary the cathode (pin 1) voltage, though. My schematic (Beitman) indicates it should be about +25V (referenced to chassis) in normal operation.

If the grid is indeed -120V or so then the wiring and components (including the picture tube socket) between vertical output transformer and CRT grid should be checked.

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A collector of TV signal boosters and UHF converters -- God help me!
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