Dave,
Thanks for the response! Do you (or anyone else) know if AM IBOC is
transmitted along with the analog signal and the sidebands 25kHz away from
the center carrier frequency simply result from the modulated carrier? Or,
are the digital channels transmitted separately from the carrier? Just
curious. I know IBOC is being called "hybrid" (analog and digital). Also,
there was something about British AM stations being mandated to go "all
digital" by a certain year. I wonder if they meant "IBOC"? Just trying to
get a handle on all of this...
There are some great Youtube videos of a European DXer in Ireland that uses
what appears to be IBOC to aid in ID'ing FM BCB stations coming in via
meteor scatter. In that case, IBOC made meteor scatter DXing much easier. As
far as AM IBOC, DXers could be missing out on a real opportunity. Each AM
IBOC "channel" is on a pretty clear frequency 25kHz on either side from the
carrier center frequency. Not too many stations currently have IBOC so
co-channel QRM on the IBOC sidebands is still minimal. Wouldn't it be
possible to design a decent receiver with great filtering that only picked
up these digital signals and DX these newest "clear" channels, propagation
permitting? Just a thought....
Re. TV DX I really had no clue other than certain DXers saying "last chance
to get in on the E-skip action". I guess the whole reason (or one of the
reasons) behind transitioning to digital in Feb. 2009 would be to free up
bandwidth (isn't current TV bandwidth/channel something like 6MHz?). So, I
wonder how much bandwidth this move will actually free up.
Agreed that the AM BCB was never meant to have IBOC or any baseband signals
over 20kHz. To accomodate IBOC with the number of channels it now has, the
AM band would need to be increased to about 4MHz. With the IBOC and the BPL
(Broadband over powerlines) decisions, the FCC isn't coming across as an
entity with very much integrity. 73.
Chris Knight
Fort Lupton, Colorado
From: "HASCALL, DAVID CIV DFAS" <[EMAIL PROTECTED]>
To: <[email protected]>, <[EMAIL PROTECTED]>
Subject: RE: Skywave noise
Date: Fri, 15 Aug 2008 13:35:22 -0400
Chris;
Not sure about ham induced TVI on the DTV's but TV DX'ing is not going
to die that easy, just because of the Transition.
In fact, DTV TV DX'ing is happening now. There are some low band DTV
stations and these ARE DX-able via Es. Several were reported this year.
Girard Westerberg was the first (IIRC) to log a DTV via Es back in 2005,
I think. Since many DTV's are UHF, tropo is big with those. Jeff
Kadet, in WC Illinois had the Texas Panhandle DTV's in a few weeks ago,
600+ miles. He also had analog UHF translators, which are uneffected by
the mandate to go to digital. Also after the transition, open chanbnels
2-6 may allow interesting loggings of Central and South American TV
stations and those in the Carribean.
FM IBOC is also being DX'ed. I caught an HD signal on 96.7 from Austin
TX, via Es, in June. That reception was over a semi-local. The HD
radios offer great analog FM sections as well as the digital. I bought
an Accurian HD radio @ Goodwill for $6 and I can hear stations on 97.7
against a strong analog on 97.9. Thanks DSP!
Digital on AM BCB? It's there - IBOC and the noise is everywhere.
Nighttime IBOC is an absolute waste and as Craig Healy pointed out it
will not work in some applications.
73,
Dave in Indy
------------------------------
Message: 5
Date: Thu, 14 Aug 2008 15:10:44 -0600
From: "CHRIS KNIGHT" <[EMAIL PROTECTED]>
Subject: Re: [IRCA] Skywave noise
To: [email protected]
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; format=flowed
This brings to mind some questions: When TV stations switch from analog
to
digital in Feb 2009, will that mean ham radio will no longer QRM TV
stations? Since the modulation/video mode will be digital will this mean
the
end of DXing TV on tropo, E-skip modes, etc.? Will digital ever be
implemented for AM BCB? If so, what impact will it have on DXing? 73s.
Chris Knight
Fort Lupton, Colorado
>From: Mike McKenna <[EMAIL PROTECTED]>
>Reply-To: Mailing list for the International Radio Club of
>America<[email protected]>
>To: Mailing list for the International Radio Club of
>America<[email protected]>
>Subject: Re: [IRCA] Skywave noise
>Date: Thu, 14 Aug 2008 13:40:36 -0700 (PDT)
>
>I agree with Kieth. I support the idea that TV channels 5 and 6 should
be
>transfered over to the FM radio service. I would also suggest that TV
>channels 2, 3 and 4 be allocated to the FM band --if possible.
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