The current version of the Horus Binary modem using both a scrambler and an
interleaver.
Without the scrambler you can end up with long runs of zeros depending on
the payload contents. Maybe it doesn't affect the modem, but it sure
doesn't sound right!
73
Mark VK5QI
On Fri, Jun 15, 2018 at 10:03 AM, David Rowe <da...@rowetel.com> wrote:
> We've used this FSK modem quite a lot for balloon telemetry and have
> wondered from time to time if we need scrambler. So far we have never
> found "the smoking gun" which would be the timing estimator falling over.
>
> Having said that I think we may have included a scrambler in one version
> of the telemetry.
>
> A related problem is burst operation ... how to get timing sync just as a
> signal starts.
>
> - David
>
>
> On 14/06/18 23:02, Steve wrote:
>
>> On Thu, Jun 14, 2018 at 12:14 AM David Rowe <da...@rowetel.com> wrote:
>>
>>>
>>> Just want to point out that, last time I tested them, the 4FSK waveforms
>>> work just fine - unmodified and without a scrambler.
>>>
>>
>> It was just a what-if that was suggested as an experiment. I'm over it
>> now.
>>
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