Re: Understanding Spurious Emissions

Skip Davis
 

Will I have been thinking along the same path and right now it is in the noodling/research stage. I need to get spice on my computer to do some modeling. 

Skip Davis, NC9O

On Jun 22, 2018, at 21:46, William Kimber <zl1tao@...> wrote:

On 21Mhz rather than a band pass/high/low filter what about 23mhz trap(s) also called notch filter. Even high Q should be wide enough to cover whole 23.8 to 23.55Mhz.   Similar for  24Mhz   needs to cover 20.17 to 20.01Mhz


Cheers,

Will

ZL1TAO


On 23/06/18 13:33, Jerry Gaffke via Groups.Io wrote:
Table two of the arrl.org filter reference shows that the 21 mhz bandpass filter 
has 15db of attenuation at 28mhz, that's 7mhz away.
We need something like 20 dB of attenuation at 2mhz away.
As Allison says, that's a tough nut to crack.

And I have my doubts about the filter I pointed to.

Jerry

On Fri, Jun 22, 2018 at 04:31 pm, Gordon Gibby wrote:
Forgot to put the link.
 
 

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