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Author Topic: Nuvistaplug  (Read 3839 times)
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KE5YTV
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« on: November 22, 2009, 03:14:14 PM »

Hi Fellows. I'd like to do the Nuvistaplug upgrade on my SP-600. Can anyone furnish a source or info on building one. Thanks and 73's, Mike Bracey, KE5YTV
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Mike
KE5YTV  Dallas, TX
"The longest trip begins with a stop at the ATM."
Pete, WA2CWA
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CQ CQ CONTEST


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« Reply #1 on: November 22, 2009, 06:00:32 PM »

Go here:
http://www.mines.uidaho.edu/~glowbugs/SP600upgrd.pdf
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Pete, WA2CWA - "A Cluttered Desk is a Sign of Genius"
WBear2GCR
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Brrrr- it's cold in the shack! Fire up the BIG RIG


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« Reply #2 on: November 22, 2009, 11:04:41 PM »


Innertesting!

Should be fairly simple to constuct!

Applicable to any receiver!!

Seems like the second stage is "grounded grid" - which seems odd to me.
I'm wondering why they didn't use a cascode arrangement instead, or a true cascade if more gain was needed to be made up... maybe their arrangement keeps the noise figure lower...

                    _-_-

                 
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K4TLJ
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« Reply #3 on: November 23, 2009, 05:14:20 AM »

A 6GU5 can be used also. Retains or increases gain and drops the noise much the same. Socket rewiring is necessary. The screen dropping resistor usually is around 680K to 1 meg! Tie pins 2 and 7 together at the socket. The suppressor grid is usually directly grounded so must be lifted and tied to the cathode.
AGC may need to be reduced by a voltage divider.
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Regards
Terry
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KE5YTV
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« Reply #4 on: November 23, 2009, 08:17:21 AM »

Thanks for your help and thoughts on this. 73's, Mike
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Mike
KE5YTV  Dallas, TX
"The longest trip begins with a stop at the ATM."
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