OK, I'll bite. What's the bandwidth of an FSK signal whose shift is 1 kHz
and whose symbol rate is limited to a maximum of 300 baud? Feel free to
parametize as necessary.
Do you think its a good idea for amateurs to transmit 150 Khz-wide signals
on HF bands like 20m that are 350 Khz wide?
73,
Dave, AA6YQ
-----Original Message-----
From: digitalradio@yahoogroups.com [mailto:digitalra...@yahoogroups.com]on
Behalf Of expeditionradio
Sent: Wednesday, March 25, 2009 9:58 PM
To: digitalradio@yahoogroups.com
Subject: [digitalradio] No FCC data bandwidth limit on HF Re: USA ham rules
> Dave AA6YQ wrote:
> There is unquestionably a bandwidth restriction
> on HF for frequency-shift keying, ....
Hi Dave,
Sorry, old friend, but you are incorrect.
In the USA data/RTTY bands 160meters-10meters,
the FSK rule is a "shift restriction". It is
not a "bandwidth restriction".
The attempt to equate or change the
"shift restriction" into a "bandwidth restriction"
was denied one year ago by FCC (May 2008).
In the "Digital Stone Age Petition" denial FCC Order
[paragraph 10] FCC said:
"Our rules do not specifically limit the
permissible bandwidth for RTTY and data emissions
in the amateur HF bands."
Plain and simple: FCC has conscientiously chosen
to set no specific bandwidth limit for RTTY/data
or phone emissions on HF/MF bands.
For those who want bandwidth limits, perhaps it
is time to reconsider a new bandwidth-based spectrum
managagement petition to FCC?
I have been a proponent of bandwidth-based spectrum
management for ham radio. I don't believe that
content-based spectrum management is conducive
to advancement of RF digital technology, and I
don't believe it is advantageous for hams.
However, "The Law of Unintended Consequences"
often applies to FCC rulings... and the petitioner
may be severely disappointed by the outcome.
A good example of unintended petition results was
the one that reduced our freedom by making the
40 and 80 meter RTTY/data sub-bands get smaller!
73 Bonnie KQ6XA
> Under the present "content-based" rules for
> hams in USA, FCC has confirmed that there isn't
> really a specific bandwidth limit for most types
> of modern digital data signals on HF... other than the
> maximum limit of the "RTTY/data subband" segment...
> for example, on 20 meters, hams in USA can
> legally transmit a 150kHz bandwidth data signal
> (14000kHz to 14150kHz).
>
> See the FCC order May 7, 2008 denying the
> "Digital Stone Age" petition:
>
http://www.hflink.com/fcc/digitalstoneage/FCC_denies_digital_stone_age_petit
ion.PDF
>
> FCC explained further [in paragraph 11 of the order] :
> "We believe that these rules provide amateur
> service licensees the flexibility to develop new
> technologies within the spectrum authorized for
> the various classes of licensees, while protecting
> other users of the spectrum from harmful interference.
> We also believe that imposing a maximum bandwidth
> limitation on data emissions would result in a loss
> of flexibility to develop and improve technologies
> as licensees' operating interests change, new
> technologies are incorporated, and frequency bands
> are reallocated."
>
> DATA SIGNAL BANDWIDTH LIMIT CHART HF/VHF/MF
> ========================================
> Band========Data Signal Bandwidth Limit
> 160 meters = 200 kHz
> 80 meters = 100 kHz
> 60 meters = 0 kHz (Data Not Authorized)
> 40 meters = 125 kHz
> 30 meters = 50 kHz
> 20 meters = 150 kHz
> 17 meters = 42 kHz
> 15 meters = 200 kHz
> 12 meters = 40 kHz
> 10 meters = 300 kHz
> 6 meters = 20 kHz
> 2 meters = 20 kHz
> 1.25 meters = 100 kHz
>
> Note1: Amateur Extra License, USA Amateur Radio Service
> Note2: current as of 03-2009
>
> More information and sources:
> http://hflink.com/bandplans/USA_BANDCHART.jpg
>
> FCC, Subpart D--Technical Standards
> §97.301 Authorized frequency bands.
> §97.307 Emission standards.
>
> 73 Bonnie KQ6XA
