[CQ-Contest] Re: ON4UN and the Ten-Tec Orion

[VR2BrettGraham]

N4HY responded to S56A's surprise at ON4UN's copying of 45 bauds
Murray code through a 150 cycle filter:

>Though I have strong doubts as Mario, this one is not warranted.
>I will await with anticipation the ARRL Lab tests.
>
>With modern RTTY programs and TU's, you can copy RTTY with one
>of the tones completely missing.  This is because all of the
>good ones for two decades after Dave Mills taught us all how,
>use a sliding threshold for the slicing detector.  Given the
>constant group delay through the FIR filters in the radio,
>I suspect John's statement about RTTY to be completely
>correct.  Do not try it however under weak signal or QRM
>conditions.  That test is a strong signal test primarily.

Mario is correct - bw = shift + (2 * rate).

John's TU or soundcard software or whatever did a good job of working
off just the mark or space tone, or if it was on both, then with how the
Orion mangled them.

Since pre-detection bandwidth was only slightly less than width of the
signal, then the amount of mangling is minor & to conclude it was
working good is not too hard to understand.

Crank it down much more & it will start to look bad.

Kinda like if Mario tried to drive his Chrysler through a gap that is okay
for my Subaru - on the other side, they both will be functional cars, but his
will have some serious damage down both the near & offsides.

Instead of establishing how good the gap is, we learn who are the best
panel-beaters.  ;^)

73, VR2BrettGraham