[RTTY] Multi Computer SO2R with N1MM

[KC4HW/Jim]

Hey Everybody, 

I see that this references N1MM but I wonder if anyone has don't the 
same analysis for Writelog?

Guess I will show my ignorance here.  

But what is a reasonable (priced) hardware solution?

Jim/KC4HW

On 23 Feb 2013 at 7:55, Jay WS7I wrote:

> If there is "any single time that their is 2 transmitted signals you are 
> in violation and are not a Single Operator.  All SO#R operators need to 
> run a hardware device to preclude this situation.  This is nothing new 
> at all.  Just the over looking by the group that it isn't a problem.  It 
> is quite easy to put a system in place and to find stations that are 
> running on two bands at once.  44 Ms of overlap means 2 signals and this 
> means you are illegal.
> 
> Also it depends a great deal what you are using for PTT and also what 
> radios are interfaced and which modem you have selected to use.
> 
> If the 20-40Ms gap is right then it needs to be controlled and at least 
> 100Ms it sounds like from this study.  But again. it should be absolute 
> hardware control and not a software situation.
> 
> 2-Signals EVER is illegal.
> 
> On 2/22/2013 5:04 PM, Mark n2qt wrote:
> > 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.
> 
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