Re: [IRCA] IBOC Revisited

[Barry McLarnon <bdm@xxxxxxxxxx>]

On Monday 17 September 2007 00:07, R. F. Tetro wrote:
> So, has the sky fallen?  Are we up against the demon forces of HD radio
> to the extent that many of us suspected?  Or, has the IBOC revolution
> merely opened up a new chapter in the history of our hobby.?  I tend to
> believe the latter.  For instance, in the past two nights I have been
> able to log several stations in the digital mode...some stronger than
> others, some solid and others with their HD signals fading in and out
> and tough to pull in.  
>
> I think this whole IBOC thing may, contrary to what many of us (myself
> included) may in the end be a boon to Dxing.  It may force us to develop
> new techniques, but it also will afford us the opportunity to pull in
> digital signals from hundreds of miles away.  For me, the bottom line is
> that it is - for the time being - a mixed blessing, but one which we
> Dxers can take advantage of.

I don't believe that any serious MW DXer would agree that this is a "boon".

Sure, using techniques such as you describe, it's still possible to do casual 
DXing - though that will increasingly diminish as more stations adopt IBOC, 
and the noise floor increases across the band.  Serious DXing, however, will 
be kaput.  Here's a litmus test: ask yourself what were your best catches 
over the last year or two, and then make a realistic assessment of whether 
they would've been possible in an IBOC environment.

I've been at it long enough to hear all the easy catches, and many of the 
not-so-easy ones.  In the last few years, I've focused mainly on target 
DXing, and exploiting transition periods (sunrise/sunset) and abnormal 
propagation (e.g., auroral conditions) to snag weak signals.  For example, 
one of my best catches last season was KKOB-770 in NM.  To snare them, I had 
to carefully tweak a phasing box to get a deep null on WABC, and then I was 
lucky enough to catch an ID from KKOB (aided by a pause in the WABC talk) 
just before they switched to night pattern.  Today, that catch would simply 
be impossible.  Nulling WABC would present a solid wall of noise from WJR 
(and WBBM, if their IBOC was on), and no amount of filtering or other signal 
processing tricks would be sufficient to pull a weak one like KKOB out.  I 
could give many more examples, but you get my drift.  Casual listening, yes, 
but serious weak signal DXing, fuggetaboutit.

As for a new chapter in DXing digital, sorry, but it's a joke.  I've been 
saying for years that the hybrid IBOC system would be a horrible performer 
over skywave channels (and groundwave too at night, unless you're near the 
transmitter), and nothing has transpired to prove me wrong.  Sure, you can 
decode some bits and pieces from some of the big blowtorches, but after that, 
you're pretty much done.  You can sit on most channels with IBOC signals 
until the cows come home, and decode zilch.  You can probably complete your 
MW digital DXing career in one weekend.  :-)  DXing digital on the AM band 
has some novelty value, but it will grow old really, really fast.

Of course, AM broadcasting does not exist to serve DXers.  The real crime is 
the effect that IBOC has on the other unwilling participants in this fiasco: 
the non-DXer listeners, and the small broadcasters.  But that's another 
story...

Barry

-- 
Barry McLarnon  VE3JF  Ottawa, ON

_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca

Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx