[Elecraft] Filters

[Bob McGraw K4TAX]

Don't recall what band(s) you are working but.........I find it amazing 
on the lower frequencies to add in 10 to 15 dB of attenuation and reduce 
the RF gain a bit provided marked improvement in the ability to pull 
weak signals out of the noise.

The idea advanced to me by others in the know is  legacy receivers such 
as the K3 and K3S provide better performance when the receiver noise 
floor is about ~10 dB below no signal band noise.     If the no signal 
band noise is -97 dBm or about S-5, and accepting the fact the receiver 
noise floor is -135 dBm, since we can't change receiver noise floor we 
must change the signal level to the receiver.   By adding 15 dB of 
attenuation and reducing the RF gain by about ~10 dB, this should put 
one in the "sweet spot" for optimum receiver performance.

Works for me every time.  The proper filter adjustments and 
configuration also helps.

73

Bob, K4TAX


On 7/1/2018 7:37 PM, Bill wrote:
>
> Sent from Mail for Windows 10
> I want to thank everyone for all the response on the lo and hi filters
> I tried your advice and they work wonders.
> My radio usually runs a s9 with noise and I was able to pull out signals hidden in
> It.
> This is really an amazing radio
> Thanks again for all the help.
> Bill
> W3WGG
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