Re: Spurs - BPF fix? #ubitx


Howard Fidel
 

All:
Have you considered changing the LPF L1 to L4 with a bandpass filter that is tuned for the operating band? That should help both harmonics and spurs and improve receive performance as well.

Howard

On 8/10/2018 1:31 PM, ajparent1/KB1GMX wrote:
Arv,

If you strip the filters as is and use them externally as an inline element they perform perfectly.
The torids used are adequate to 10W, maybe more with a good SWR.  For those running
more power or maxed out you need a bigger filter components.

Like I proposed earlier in this one in  #56618...

IF you take out the 30mhz (actually 33mhz) low pass that 9element one and replace it
with three of the filters used at the output and one band pass for say 10m you will
get 3-near 20mhz coverage with no issue RX and clean up the TX and 10M becomes
usable. and the CW harmonics are lower as well.

Its three low pass filters (no tune), and one wide bandpass for 10M.

Allison


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