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/digitalradio/members;_ylc=X3oDMTJmbzY3MjhrBF9TAzk3MzU5NzE0BGdycElkAzE4NzExODMEZ3Jwc3BJZAMxNzA1MDYzMTA4BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzEyNjY1OTc1MzA-?o=6
<http://groups.yahoo.com/group/digitalradio/members;_ylc=X3oDMTJmbzY3MjhrBF9TAzk3MzU5NzE0BGdycElkAzE4NzExODMEZ3Jwc3BJZAMxNzA1MDYzMTA4BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzEyNjY1OTc1MzA-?o=6>>Joe,
> N8FQ...
>
> http://www.arrl.org/FandES/field/regulations/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
>
