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20th Aug 2014, 8:05 pm | #1 |
Pentode
Join Date: Oct 2009
Location: Bergen, North Holland, The Netherlands
Posts: 177
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Poor man's Griddipper
From an old American magazine there is a nice article about a valveless GDO.
Source : Radio & Television News¨ Jard N. Edit: I´m afraid that the attachments are too small to read, So I will re-post them as soon as I found out how to do that. Last edited by neutronic; 20th Aug 2014 at 8:26 pm. |
20th Aug 2014, 9:19 pm | #2 |
Pentode
Join Date: Oct 2009
Location: Bergen, North Holland, The Netherlands
Posts: 177
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Re: Poor man´s Griddipper
Sorry, but I didn't manage to make readable attachments, so I'll give the link to the article.
Pages 60 , 61 ,112 and a small part at the top of P.113 http://www.americanradiohistory.com/...-1949-05-R.pdf Jard N. |
21st Aug 2014, 9:31 am | #3 |
Heptode
Join Date: Apr 2003
Location: Ayr, Ayrshire, UK.
Posts: 630
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Re: Poor man's Griddipper
Thanks for trying to post this article, but the problem is that the original is unreadable !
Andy
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21st Aug 2014, 10:28 am | #4 |
Pentode
Join Date: Feb 2005
Location: Longfield, Kent, UK.
Posts: 239
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Re: Poor man's Griddipper
I have downloaded the pdf from the link provided by neutronic. I use Adobe Acrobat and the readability is fine, including the component details.
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21st Aug 2014, 10:40 am | #5 |
Heptode
Join Date: Apr 2003
Location: Ayr, Ayrshire, UK.
Posts: 630
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Re: Poor man's Griddipper
I stand corrected
I was using the reader in my browser. If you download the PDF then view it it's fine. Andy
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22nd Aug 2014, 1:51 am | #6 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,924
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Re: Poor man's Griddipper
I'm always interested in GDO's...but, if your are considering this as a new piece of practical test equipment (as distinct from the restoration of some existing item) it may not be a "poor man's solution". The 6J6 (ECC91) is one valve I don't have in my junk box; don't recall seeing that used in very much. Depending on your junk box, the valve and the mains psu could well drive the costs above that of a FET and and PP3 battery
B |
22nd Aug 2014, 2:32 am | #7 |
Heptode
Join Date: Apr 2009
Location: Scratby, Norfolk, UK.
Posts: 648
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Re: Poor man's Griddipper
Hi
It looks to me a very awkward arrangement. and it wasn't that hard to build a GDO anyway. Incidentally I had a Q-Max GDO many years ago which used an ECC83? double triode, one half being used for the oscillator, and the other half was diode strapped as the HT rectifier. It worked very well. Kind regards Dave Kind regards Dave |
22nd Aug 2014, 7:07 am | #8 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,800
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Re: Poor man's Griddipper
ECC81 was more common for GDO designs allowing them to get to higher frequencies. The higher gain of the ECC83 wasn't needed, but the wider bandwidth of the ECC81 was useful.
David
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22nd Aug 2014, 3:16 pm | #9 | |
Pentode
Join Date: Oct 2009
Location: Bergen, North Holland, The Netherlands
Posts: 177
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Re: Poor man's Griddipper
Quote:
What has a 6J6 to do with a valveless GDO? In the whole story the word valve or tube is never read. BTW. Tthe tube/valve/röhre/lampe/buis to use nowadays is the EC92 cq 6AB4 Jard N. |
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22nd Aug 2014, 4:33 pm | #10 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,924
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Re: Poor man's Griddipper
Sorry , I was looking at the feature on page 42.
Those were the days - two GDO's in one mag! I need to double check the index; maybe there are more than 2 GDO's in there! Interesting mag. Makes me thing of good old "73". B |