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 Post subject: Re: Popular Electronics 1955. Build a 1 Tube Radio 1D8-
PostPosted: Jan Wed 31, 2018 10:29 am 
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Joined: Jan Mon 17, 2011 2:10 am
Posts: 60
Location: Revere,Massachusetts U.S.A.
Thank You to everyone for taking the time to help with information and more. I will this project within a few days, when I’m done I will post pics.
Tony


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 Post subject: Re: Popular Electronics 1955. Build a 1 Tube Radio 1D8-
PostPosted: Feb Fri 02, 2018 7:15 pm 
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Joined: Jan Tue 16, 2007 7:02 am
Posts: 2274
Location: Lexington, KY USA
Forgive me if this has already been pointed-out, but the original design was all about utilizing all three parts of the "3 in 1" tube, and not about maximizing radio performance.

The same tube will make a much hotter radio when the triode section is used as a reginerative detector. Forget about the diode .section.

Should be pretty easy to modify the original to make a regin after it's built and checked-out.

Ted


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 Post subject: Re: Popular Electronics 1955. Build a 1 Tube Radio 1D8-
PostPosted: Feb Sat 03, 2018 2:04 am 
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Joined: Dec Sun 14, 2008 3:33 pm
Posts: 650
Location: Tokyo
You could use that diode with a regen. There's some information here:

https://www.radiomuseum.org/forum/proje ... eiver.html

Scroll down past the regen project to Joe Sousa's comments (a little past halfway),
'Optimized amplifier-detector and regeneration methods'

The idea is to use the diode as the AM detector before the regenerative amplifier. With a triode, this lets you raise the voltage on the detector and thereby get more audio gain. Also, a diode can handle much stronger signals than a regen's gridleak detector.

There's another reason: the AM sensitivity of a diode is said to be greater than that of a gridleak detector's cathode to control grid 'diode'.

Anyway, it's something to experiment with. To begin with, just connect the diode plate to the regen's control grid.

Another direction: perhaps the diode could be used as a simple shunt noise limiter between the detector stage and the audio amp.

Rob


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 Post subject: Re: Popular Electronics 1955. Build a 1 Tube Radio 1D8-
PostPosted: Feb Sat 03, 2018 11:44 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 7523
Location: Beautiful Downtown Burbank CA
Mike Toon wrote:
Then this Bogen T-725 using wh/violet will have to do.

Image


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 Post subject: Re: Popular Electronics 1955. Build a 1 Tube Radio 1D8-
PostPosted: Feb Sun 04, 2018 2:21 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 1398
Location: Cambridge MN USA
Quote:
Forgive me if this has already been pointed-out, but the original design was all about utilizing all three parts of the "3 in 1" tube, and not about maximizing radio performance.


Very true, but I had the misfortune of growing up just outside of KSTP's (AM 1500, 50kW) 1V/m blanketing contour. Any simple circuit radio would pick up just that one station at worst, or at best it would still bleed over any of the others I could hear. Hence I've always had a disdain for circuits that didn't somehow maximize performance. No sense in building a radio just to hear something I wasn't interested in.

Scott Todd


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 Post subject: Re: Popular Electronics 1955. Build a 1 Tube Radio 1D8-
PostPosted: Feb Sun 04, 2018 1:05 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 4774
Location: Gainesville, Florida
you should introduce your true circuit for comparison :)


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