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  #1  
Old 03-21-2018, 07:04 AM
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decojoe67 decojoe67 is offline
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1920'S Jenkins Radiovisor on eBay

https://www.ebay.com/itm/Very-Rare-F...8AAOSwZrtaoqoz
Now this is one cool and very rare piece of television history. I like it just as it is with it's great patina. I'm still amazed at how far back sight and sound television was made available to the public. I already envy whoever will be it's new caretaker!
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Old 03-21-2018, 11:22 AM
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I think this is a Jenkins Scanning Drum versus Scanning Disk television. http://www.earlytelevision.org/jenkins_202.html
There appears to be 7 surviving sets according to the counts on the ETF web site. I wonder if this is another unknown set. I think the price is high based on sales in the last 5 years. I'm lucky I got my Western mechanical TV when the prices were low about 4 years ago. I found an Escutcheon from a Jenkin's JD30 radio on eBay last year for $20 so I now need to find the rest of the radio.
Can you imagine the guy who took the escutcheon off and throwing the radio cabinet away?
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Last edited by rld-tv01; 03-21-2018 at 11:30 AM.
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Old 03-21-2018, 01:24 PM
EdKozk2 EdKozk2 is offline
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Thanks for posting the link Decojoe,
This is the first picture of a Jenkins Drum scanner I've seen.
Ed
After taking a closer look at the photographs, the radiovisor looks to be
a standard scanning disk.

Last edited by EdKozk2; 03-21-2018 at 08:09 PM.
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  #4  
Old 03-21-2018, 02:37 PM
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I find it interesting the first apple computer would sell for $800K in 2016 while early mechanical televisions sell in the $3K-$15K range. I saw Western Television Model 41 listed for $15K and I believe the buyer offer was close to that. I believe a Jenkins model 100 was sold in the $7K-9K range about 10 years ago. The Jenkins model 100 was never offered with a cabinet which I think diminishes today's achievable price. A Western television Visionette was in the $6-$7K range 10 years ago.
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Old 03-21-2018, 02:49 PM
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Quote:
Originally Posted by EdKozk2 View Post
Thanks for posting the link Decojoe,
This is the first picture of a Jenkins Drum scanner I've seen.
Ed
After taking a closer look at the photographs, the radiovisor looks to be
a standard scanning disk using a mirror to reflect the image into a magnifier.
Same idea as my Stewart Warner 9100 mirror set.
I think listing pictures 4 and 5 show a scanning drum. The tag shows model 202 which is listed on ETF web site as a scanning drum TV set. The ETF web site also show a Jenkins model 302 with a scanning disk.
http://www.earlytelevision.org/jenkins_302.html

Last edited by rld-tv01; 03-21-2018 at 03:00 PM.
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Old 03-21-2018, 06:29 PM
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Definitely a scanning drum. The opening bid is about 4X what I'd guess they were worth to anyone.
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Old 03-21-2018, 06:55 PM
old_coot88 old_coot88 is offline
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Quote:
Originally Posted by decojoe67 View Post
https://www.ebay.com/itm/Very-Rare-F...8AAOSwZrtaoqoz
Now this is one cool and very rare piece of television history. I like it just as it is with it's great patina. I'm still amazed at how far back sight and sound television was made available to the public. I already envy whoever will be it's new caretaker!
Very cool! It looks like the drum does horizontal sweep in combination with a disc doing vertical sweep. The drum looks direct-drive on the motor shaft, with the disc on a 90 degree angle drive.
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Old 03-21-2018, 08:08 PM
EdKozk2 EdKozk2 is offline
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RTD-TV01,
Your right about the drum scanner. I thought the can was a heat shield with cooling because of the hole spaced around the can. So I,m guessing the rotating can sets the frame rate and the rotating disk sets the lines per frame rate. I'm not sure why I thought it used a mirror?
Ed
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Old 03-21-2018, 09:00 PM
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Quote:
Originally Posted by rld-tv01 View Post
I find it interesting the first apple computer would sell for $800K in 2016 while early mechanical televisions sell in the $3K-$15K range.
As someone who works in the old computers hobby, when it comes to Apple products there is a term called the Reality Distortion Field.
To them the Apple I is this magical PCB with a bunch of IC's that was created by a mythical man (implying Woz was somehow not at all responsible for the fact he did design, prototype and test build the computer) who created the GUI and the biggest computer company in the world and this is a national treasure symbolizing the humble beginning of a technological world leader and the few remaining original units are priceless.
These things...uh...they look like some retro steampunk thing. Wasn't that in an episode of Doctor Who?
It's an Each to their Own thing. The international acceptence is that they are just stupid.

I could see it sell for $38K if it was professionally restored. It has the ability to become a really nice and extremely rare museum piece. Right now however I really could not see it going over $10000.

* Italics denote actual RDF
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Old 03-21-2018, 09:34 PM
old_coot88 old_coot88 is offline
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Quote:
Originally Posted by EdKozk2 View Post
RTD-TV01,
Your right about the drum scanner. I thought the can was a heat shield with cooling because of the hole spaced around the can. So I,m guessing the rotating can sets the frame rate and the rotating disk sets the lines per frame rate. I'm not sure why I thought it used a mirror?
Ed
I dunno, it looks more like the drum sets the H rate, and the spiral cuts in the disc set the V rate. The drum and disc are locked together arithmetically by the gearing, and the camera would need to have an identical mechanism. It wouldn't be compatible with any other scanning format. Seems like, anyhow.

Wonder if this format originally used a flying-spot scanner rather than a "camera".

Last edited by old_coot88; 03-21-2018 at 09:38 PM.
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  #11  
Old 03-22-2018, 12:56 AM
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I believe the drum has three spirals of scanning holes, so it can be 3 times smaller than a drum that has all the holes in one big spiral. Then, the disc has spiral slots that select one of the spirals of holes on the drum for each revolution of the drum. It then takes three revolutions of the drum to create one picture.
Edit: the scanning pattern would be the ordinary left to right, top to bottom, but the top third of the picture comes from the top spiral of holes, the middle third from the middle spiral, etc. If the picture rate was, for example, 10 frames per second, the drum would turn at 30 rps or 1800 rpm.
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Last edited by old_tv_nut; 03-22-2018 at 01:03 AM.
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