[RTTY] Multi Computer SO2R with N1MM

[Stein-Roar Brobakken]

to use N1MM in Multi computer SO2R , must you use SINGLE op or MULTI OP
mode ????

73s LA6FJA Rag


2013/2/23 Mark n2qt <n2qt at verizon.net>

> In W0YK's email on AA5AU's WPX notes in talking about using N1MM
> for multicomputer SO2R he stated:
>
> "I found that the interlock is very slow and 2-3 characters overlap
> transmission from both radios.  OTOH, no software interlocks can guarantee
> the absence of two signals, if even for milli-seconds, so the operator is
> responsible via a hardware interlock to not transmit simultaneously."
>
>
> Since I had used this approach to operate SO#R I decided to measure
> any possible overlap.  I would set one rig to cq and then interrupt it by
> transmitting on the other rig.  I did this where one rig was controlled by
> a networked computer and then with the more typical single computer
> N1MM SO2R.  I used a storage scope to look at the rf output from the
> rigs.
>
> For the networked computer configuration the the worst case was 566ms
> of overlap with typical overlaps of over 400 ms.   As Ed stated this is
> long
> enough for several characters to be sent in violation of one signal at a
> time.
> Some other interlock is needed for rule compliance.
>
> However when using N1MM in its more typical single computer SO2R mode,
> it is obvious the programmers worked to eliminate this overlap.  There
> typically
> was a 20 - 40 ms gap with NO RF emitted, between one rig's transmit signal
> dropping and the second rig's transmit coming up.  After many sequences I
> did
> manage to get one series where there was just about 44ms of overlap.  This
> is well less than one half character's worth of time.  I personally feel
> good about
> this performance.
>
> The computer used was a HEX Core AMD running WinXp.  I had multiple receive
> windows, packet,  along with two instances of CWSkimmer running.  I assume
> for the rare instance of overlap, it was induced by a poorly timed
> resource demand
> from one of these other applications.   N1MM was set for last one wins for
> SO2R
> priority and 'stop other rig's transmit when this rig transmits' networked
> priority.
>
> Mark n2qt
>
>
> ______________________________**_________________
> RTTY mailing list
> RTTY at contesting.com
> http://lists.contesting.com/**mailman/listinfo/rtty<http://lists.contesting.com/mailman/listinfo/rtty>
>