[digitalradio] A closer look at ROS]]
andre.kesteloot at verizon.net
Mon Feb 22 20:35:15 CST 2010
Essentially, our (AMRAD) first experiments were in Frequency Hopping
mode,and we were hopping all over most of the 2 meter band (using
modified ICOM hand-helds with extra wires all over. :-)
As long as we did not dwell too long on the input frequency of the
various repeaters, we did not create (too much) havoc.
Then I started Direct Sequence SS on the 70cm band (see the ARRL SS
Source book) and there was no detectable interference at all on that
My experiments were eventually duplicated by James G1PVZ, under the
watchful eyes of the British Authorities, also without interference,
as I recall.
All the details of what we were authorized to do, as well as what we
actually did do, is detailed in the ARRL SS Sourcebook
Hope this helps,
On Feb 22, 2010, at 16:17, Tom Azlin N4ZPT <n4zpt at cox.net> wrote:
> Hi Andre,
> Still does not answer my question. What was the concern at the time
> AMRAD was working SS approvals. If a signal were inside a 3KHz voice
> grade bandwidth would those original fears be applicable?
> I certainly accept that there is no free lunch. that is my favorite
> systems trade comment.
> 73, Tom n4zpt
> On 2/22/2010 1:54 PM, Andre Kesteloot wrote:
>> Sent from my iPhone (apparent spelling errors are due mainly to the
>> thickness of my index and the size of the iPhone keyboard).
>> On Feb 22, 2010, at 11:31, Tom Azlin N4ZPT <n4zpt at cox.net> wrote:
>>> Spreading is adding known redundancy otherwise you would not get
>>> spreading gain.
>> Alas, there is no such thing as a free lunch.
>> You only get spreading "gain" because you first introduced spreading
>> André N4ICK
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