[Namaste-dev] Re: Part 97 Restrictions for 2m, 70cm, 9cm, 5cm

Frank Brickle brickle at pobox.com
Fri May 9 09:16:15 PDT 2008


On Thu, May 8, 2008 at 8:44 PM, Michelle <w5nyv at yahoo.com> wrote:

> ...
>
> USA band plan
> 144.300 - 144.500 MHz Satellite
> 145.510 - 145.790 MHz FM simplex, digital, and Satellite. Channels are
> spaced 20kHz apart (145.510, 145.530, 145.550).
> 145.800 - 146.00 MHz Satellite
>
>  ...
>
> 2. "...A RTTY, data or multiplexed emission using an unspecified digital
> code under the limitations listed in §97.309(b) of this Part also may be
> transmitted. The authorized bandwidth is 20 kHz."
> ...
>
> I think that the 20 kHz is what applies here, because of the "using an
> unspecified digital code"...
>
> Did I interpret that correctly?
>
Sounds right to me.

> Next I considered 70cm.
>
> In the US and Australia...420 to 450 MHz...in Canada...430 - 450 MHz; in
> the UK...430 - 440 MHz.
>
> ARRL US band plan
>
>  435.00 - 438.00 MHz Satellite only (internationally)
> ...
>
> 1. ...A RTTY, data or multiplexed emission using an unspecified digital
> code under the limitations listed in §97.309(b) of this Part also may be
> transmitted. The authorized bandwidth is 100 kHz.
>
> Using the same reasoning as for 2m, it sounds like the digital mode
> bandwidth for 70cm would be 100kHz, since we are not using one of the
> specified digital codes.
>
Hypothetically, then, it's

20kHz for a single signal within 145.8 - 146. Is 20kHz wide enough to
exploit FHSS? Is there any merit to the claim that a single hop must be
limited to 20kHz, but successive hops can cover a wider range? Hopping
within 20kHz can be implemented entirely on the Siren. Hopping over 200kHz
needs to be external.

The same arguments would apply, mutatis mutandis, to 435 - 438, except that
the Siren could not cover 100kHz in any configuration by itself.


73
Frank
AB2KT


-- 
The only thing we have to fear is whatever comes along next. -- Austin Cline
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://amsat.org/pipermail/namaste-dev/attachments/20080509/b4367440/attachment.html


More information about the Namaste-dev mailing list