Re: LF: Re: WRC-12 Approves the New 472-479 kHz Amateur Radio Allocation

[Warren Ziegler <wd2xgj@gmail.com>]

Clemens,

   NDB receivers that I have seen typically use an AM filter so that
you can also use it for DFing with standard medium wave stations, so
assume the bandwidth is 6kHz or greater.

-- 
73 Warren K2ORS
                WD2XGJ
                WD2XSH/23
                WE2XEB/2
                WE2XGR/1



On Wed, Feb 15, 2012 at 4:40 PM, Clemens  Paul <cpaul@gmx.net> wrote:
> Greetings all,
>
> I wonder what "secondary user on non-interference basis" means in practice.
> As we know most NDBs are AM modulated with about 1kHz.
> Now it would be interesting to know what selectivity/bandwidth DF receivers
> for NDBs in aeroplanes might have.
> Imagine they have 1kHz or even 2kHz (quite possible).
> For non interfering such a receiver one would have to stay well without that
> BW.
> Hence with a few NDBs spread between 422 and 479kHz there would
> virtually remain no usable frequency for us amateurs if we wanted to make
> 100% sure not to interfere any aeroplanes' beacon reception.
>
> 73
> Clemens
> DL4RAJ
>
>



-- 
73 Warren K2ORS
                WD2XGJ
                WD2XSH/23
                WE2XEB/2
                WE2XGR/1