FT991 Noise Blanker working much better than FTdx3000

[KB1SNJ]

Just noticed that the Yaesu FT991 NB works 100% on the same QRM noise which breaks through the FTdx3000 NB with a sputtering noise. I adjusted both NB levels, same result.

Could this be a defect in the 3000 somehow?

Here's a short example video I made of it:
https://youtu.be/mQi4ek16laA

[K6BRN]

Chris:

No.

Brian - K6BRN

[KB1SNJ]

So why the breakthrough buzz on 3000 and not 991 I wonder?

[K6BRN]

Chris:

Hard to tell without sitting in front of the radio and actually working through the noise problem.  The FT-991A and FTDX-3000 have a rather extensive set of interference mitigation options, and they all interact to a degree, including preamps, attenuators, filters, time constants, etc.  And the antenna setup and noise source would have to be identical for a decent comparison.  Ground and power connection differences can be critical, too, since a lot of "impulse" noise can travel through those channels.  If you are using the the radios in a mobile environment, perhaps the FT-991A is more optimized to that environment - I do not.

I have both radios at QTH#1, cross connected to a small "farm" of six antennas  through a switch matrix and have found both noise blankers to be similarly effective in MY noise environment.  But your environment is different.  However, I've used the FTDX-3000 blanker enough to know if it was "defective".  It's not.  And neither the FT-991A nor FTDX-3000 blankers are as effective as my external West Mountain Radio CLRdsp processor, in my noise environment.  None are "defective".  Just different.

Best Regards,

Brian - K6BRN

[KB1SNJ]

Thanks Brian, I can add that both are next to my couch, on same antenna (switch). I even moved the 3000 away from the astron PS in in case it was that. I can't think of any other apples to apples. I will keep testing and report any new discoveries.  This was surprising though as i assumed that the NB and DSP circuits are *probably* about the same in both radios.