Jose,
We want to be able to use the mode on HF, but it is not our decision,
but our FCC's decision, for whatever reasons they currently think are
valid. Fortunately, it may work well on VHF and HF, so I plan to find out.
73 - Skip KH6TY
jose alberto nieto ros wrote:
We can see it as we want, but if OLIVIA is legal, ROS is legal.
------------------------------------------------------------------------
*De:* KH6TY <kh...@comcast.net>
*Para:* digitalradio@yahoogroups.com
*Enviado:* vie,19 febrero, 2010 19:19
*Asunto:* Re: [digitalradio] Re: ROS, legal in USA?
All,
If we accept the fact that a SSB transmitter with sufficient carrier
suppression simply generates an RF carrier equal to the suppressed
carrier frequency plus the tone frequency (USB), then frequency
hopping is frequency hopping (spread spectrum), regardless of how the
carriers are generated. That is really too bad for US hams as all
morning I have been receiving alerts and printouts from many stations
on 14.080 - many times when the ROS signal can hardly be heard above
the noise.
I'm afraid that Andy's concerns are real, and unless the FCC clarifies
otherwise, ROS is currently illegal in the US in my personal opinion
and interpretation of the FCC rules.
However, it looks like a worthwhile mode to test on UHF (432 MHz)
where SS "is" allowed and we will be doing that during our daily
digital experiments every morning on 432.090 SSB. The Doppler shift,
multipath distortion, and "fast flutter", as well as QSB often as deep
as 15 dB, often make even S3 phone signals unintelligible. We have
been also been testing extensively with DominoEx 4 on FM (DominoEX
does not survive Doppler shift well on SSB) and Olivia 16-500 and
4-500 on both FM and SSB, often with better copy than with SSB
phone, and especially so when signals are near the noise threshold.
The path length is 200 miles, so signals are usually near the noise
threshold during these winter months where there is no propagation
enhancement.
I'll post the results of our tests on 432 MHz here during the next two
weeks as we compare ROS to Olivia. So far, plain old CW can be copied
when even Olivia cannot, but the CW "note" is very raspy sounding,
much like it is during aroura communication. It would help a lot if it
were possible to select alternate soundcards and many of us on UHF and
VHF are using a second soundcard for digital operations.
73 - Skip KH6TY
nietorosdj wrote:
One comment: It is not the same a Spread Spectrum Transceiver (like
military radios) that to send digital data into an audio channel on
standard SSB transceiver. They are different things. So, when we read
Spread Spectrum is not legal, first we must know what we are reading.
--- In digitalradio@ yahoogroups. com
<mailto:digitalradio%40yahoogroups.com>, Andy obrien <k3uka...@.. .>
wrote:
>
> <http://groups. yahoo.com/ group/digitalrad io/members;
_ylc=X3oDMTJmbzY 3MjhrBF9TAzk3MzU 5NzE0BGdycElkAzE 4NzExODMEZ3Jwc3B
JZAMxNzA1MDYzMTA 4BHNlYwN2dGwEc2x rA3ZtYnJzBHN0aW1 lAzEyNjY1OTc1MzA
-?o=6
<http://groups.yahoo.com/group/digitalradio/members;_ylc=X3oDMTJmbzY3MjhrBF9TAzk3MzU5NzE0BGdycElkAzE4NzExODMEZ3Jwc3BJZAMxNzA1MDYzMTA4BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzEyNjY1OTc1MzA-?o=6>>Joe,
> N8FQ...
>
> http://www.arrl. org/FandES/ field/regulation s/news/part97/
d-305.html
<http://www.arrl.org/FandES/field/regulations/news/part97/d-305.html>
>
> Describes Spread Spectrum as not permitted on HF. Is there another
part of
> part 97 I am missing ?
>
> Andy K3UK
>