[1000mp] Noise Blanker Mod results

[Pete Smith]

Hi Jaako -- thank you for doing this research.  I think this will go a long 
way to clarify things.

At 10:03 PM 3/22/03 +0200, you wrote:
>...
>However - my claim that you do not need to do the noise blanker mod to
>maintain high dynamics is still valid. You just need to keep nb OFF and
>value lower than B11/A11. Or keep nb ON all the time. My proposal is to keep
>nb OFF and the setting low and switch nb ON only when there is an
>interference you want to suppress (makes sense...)
>
>If you do the noise blanker mod then nb value, switching it ON or OFF have
>no effect on receiver IMDR. I propose doing the mod -  it is easy to do and
>the performance is very good.

I may do the modification, although I frankly tell you I am nervous about 
removing the SMT resistor in order to do it.

One question, though -- it is not clear to me if the first column of your 
large chart was measured with the blanker off on the front panel AND gain 
set at A1, or with the blanker switched off but the gain still at B15?

Either way, if I read your test results correctly, there is no degradation 
in IMD performance if you keep the NB on.  Alternatively, if you turn the 
NB off, close-in IMD performance is degraded VERY badly (69.7 vs 80.6 
dB).  Isn't this the EXACT opposite of the conventional wisdom for the 
unmodified 1000D and 1000MP blankers?

Based on your results, why not leave the NB on all the time?  Is there some 
other negative impact on performance (particularly in a contest environment?

73, Pete N4ZR