[Amps] teeny copper strap

R L Measures r at somis.org
Sat Jun 10 05:04:15 EDT 2006


On Jun 9, 2006, at 3:16 PM, Roy Koeppe wrote:

> Concerning,
>
> " ...is there any non-radio source of appropriate stuff for  
> grounding my
> SB-220 grids?...(etc.)"
>
>
> Sorry, but I have to bring this up. It seems to me what's good for the
> goose is good for the gander. If low Q parasitic suppressors are
> advantageous for their purpose, then grid straps would be also.

So it would seem, Roy.  In my SB-220, using a dip-meter, I madea  
before and after resonance f comparison between direct-grounding the  
grid pins and grounding them with caps.  Not only was the difference  
in f only c. 1.3%, which seems pretty insignificant, with the csps  
the f was higher, which should mean better VHF stability.

> Wide
> straps with low inductance

According to Fred Terman, L  is a logarithmic function of width, so a  
conductor that is twice as wide as another has only slightly less L.

> but not with high Q should tame the grid
> resonances at least slightly. Comes to mind, wide sized "solder wick"
> fully saturated with solder to form a non-stranded, solder-coated  
> handy
> strap. Easy to obtain as well. It loves to be soldered. And then there
> are tin cans to be snipped into strips??


Since tin exhibits moderate VHF-Q, it seems like grounding the the  
grid through 3 chip-resistors might be better.

If you make the mod, it would be interesting to see what you see with  
a dip-meter.
>
> 73,    Roy     K6XK
>
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R L MEASURES, AG6K. 805-386-3734
r at somis.org





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