RadioBanter - View Single Post - WJ-8716 review

February 2nd 06, 07:45 PM posted to rec.radio.shortwave

David wrote:
On 2 Feb 2006 09:21:03 -0800, wrote:

Now I get to play with the radio hooked up to an antenna. WOW. This is
amazing. It's got 5 filters (300 khz, 1 khz, 3.2kHz, 6kHz, and 16kHZ).
The filters have the sharpest edges I've ever heard, and I've used a
lot of ham and communications receivers over the years. If there's a
hetrodyne, I just shift the center frequency or put on a narrower
filter and that hetrodyne is GONE. Maybe every other crystal filter
I've ever heard before is crap, but I doubt it, most of them are pretty
good but they don't make a hetrodyne that's 9 S-units above the desired
signal and a couple hundred Hz away disappear like that!

I doubt it's the filters themselves as much as the lack of leakage
around them.

I use crystal filters designed for the Racal 6790 in my AOR 7030+. The
shape factor is 1.33.

Typically, filters with a shape factor of below 2 are considered "pretty
good", and Kiwa is proud of offering premium filters for my radio with a
shape factor of 1.65.