Steve, VK6VZ wrote:
"Currently, my Yaesu FT1000MP is fitted with the stock Yaesu 500Hz
crystal filter in the 8.215MHz IF and the accessory Collins 500Hz
mechanical filter in the 455KHz IF. For very weak signal work, I am
wondering if I would get a useful/noticeable increase in signal/noise
ratio by fitting an Inrad 100Hz filter (in the 455KHz IF)?"
==========
The Collins 500Hz mechanical filter has very broad skirts and you'll
notice a big S/N improvement if you go to 250Hz filters.
About a year ago I installed the INRAD 125Hz filter in my MP and was
pleased to notice a big S/N improvement compared to the 250 Hz filters.
MY MP has the following CW filters installed:
8.215 IF 455 IF
-------- ------
500 500 (both Yaesu)
250 250 (both Yaesu)
125 (INRAD)
The 500Hz and 250Hz filters are installed in their normal slots. The
125Hz filter is installed in the 455IF 2.0kHz slot and works fine there.
Unlike the Mk V and Field, the front panel filter selection capability on
my original MP makes it easy to select any CW filter combination desired.
For weak signal work on 160, I usually have the 8.215 250Hz and 455
125Hz selected. I also often use the MP's 60Hz DSP audio filter, which
also helps.
73, de Earl, K6SE
|