[Icom] Filtering at 9 MHz vs. 455 kHz

[Dana Hoggatt]

You said:

	I am quite pleased with the performance, but wonder if
	I will get significantly improved filtering performance
	if I also place a 500 Hz filter in the 9 MHz IF stage.

There's no doubt that the second filter will improve your
performance.  The problem is judging how "significant" the
improvement will be.  We end up entering the realm of personal
preferences here, so don't expect a consensus.

Some will probably say to stick with the single filter.
If it aint't broke, don't fix it.  After all, you said you
were pleased.

The "brasspounders" in my local club prefer the dual filters,
particularly in tough conditions like on Field Day.

Adding the second filter will give you an added benefit
you may not have realized yet.  Using the Twin Pass Band Tuning
(TPBT), you can vary your effective filter width anywhere
from 100-500 Hz.  This works very well.

Also, you have a lot more choices than you realize.  Check out
the information in the IC-746 FAQ at:

	http://www.qsl.net/kb9sss/IC-746/IC746-faq.txt

for more information.

I hope that helps.

Dana, KB9SSS