[Yaesu] Mechanical vs. Crystal filters

[mikea]

On Wed, Aug 16, 2006 at 09:20:10PM +0200, Hans Remeeus wrote:
> 4 x yes.
> 
> Some examples:
> 
> The Inrad #705F (500 Hz) and #712F (300 Hz) Collins filter have a shape 
> factor of more than 2.5.
> 
> #705F -  BW6: 595 Hz, BW60: 1.560 Hz (pancake)
> #712F -  BW6: 340 Hz, BW60: 850 Hz
> 
> The Inrad #702 (2100 Hz) and #714 (1800 Hz) criystal filters have a 
> shape factor of 1.5.
> 
> #702 -  BW6: 2.175, BW60: 3.350 Hz
> #714 -  BW6: 1.925 Hz, BW60: 2.862 Hz
> 
> All are 455 kHz IF-filters.
> 
> Those are significant differences!

Hans, 

You're using European notation? ("," between units and tenths, "." 
between 10^3 and 10^2)

Here (US) we'd write it 1,350 Hz or 1.350 KHz. Not saying our way is
better, just clarifying how it's written before someone starts asking 
how Inrad achieves less than a 2 Hz bandwidth at 60 dB down. 

-- 
Mike Andrews, W5EGO
mikea at mikea.ath.cx
Tired old sysadmin