[Elecraft] 250 Hz and 400 Hz Filter Measurements

[Bill W4ZV]

Kok Chen wrote:
> 
> So, I would like to suggest that Jim try using a stronger noise source
> than band noise. 
> 

Yes, think about this using common sense.  Assuming typical band noise might
typically be -120 to -130 dBm, and the internal noise floor of the radio is
-137 dBm, you cannot expect to measure 60-70 dB down from such a low level
noise source without running into internal noise floor problems.

KS7D's swept measurement program does a much better job and requires only a
signal source such as the XG1 or XG1.  

http://www.ks7d.com/Downloads.htm

It also removes typical mistakes such as:

1.  Not remembering to turn AGC Off.
2.  Not remembering to lock the DSP filter much higher than the filter being
measured so that there is no cascading effect.
3.  Not adjusting Pitch to a frequency such that the low end is not
truncated at 200 Hz by the MCU shifting the lower cutoff at low Pitch
settings.
4.  Not remembering the effect Mode (CW vs Data A) can have on measurements

73,  Bill




-- 
View this message in context: http://elecraft.365791.n2.nabble.com/250-Hz-and-400-Hz-Filter-Measurements-tp5300671p5308596.html
Sent from the Elecraft mailing list archive at Nabble.com.