Richard Fiorello writes:
>The fact that the ict90 was preprogrammed with tv audio was a nice extra. 
>If I understand things correctly that will be history come next year.

	Someone asked what we would hear in place of the audio.
A good guess is nothing much. When the analog VHF channels go
dark next February, we will probably not hear anything for years
because it will take that long for industry and government to
agree on what to use some of those bands for. The commercial and
public safety folks all want pieces of 700 and 800 and up
spectrum for cell phones and other similar gadgets but who's
going to want 54 through 88 megahertz?

	It may turn out to be useful for Part15-style devices
such as wireless microphones and baby monitors, etc. It
certainly won't be as good for cell phones and wireless PDA's as
UHF.

	So, for a long time, you won't hear anything except hiss
and a little RFI from computers and computer networks and then,
when something does finally occupy the frequencies, it may be
digital such as pagers or data networks.

>As for digital converters,  does the converter have its own remote or can 
>you still use your own tv remote?

	They will be like the cable box you may have had to give
cable capability to your older televisions. You set the
television to an unused channel in the area such as 3 or 4 and
then you do all your tuning and channel changing via the
converter box.


>Also, apparently most channel numbers will change.  If this is indeed the 
>case it should be an interesting learning curve for some.

	That is the thing I mentioned in a previous message. The
digital channels send out a code that tells your receiver that X
digital channel is paired with Y analog channel which makes it
easier for the viewer to know where to look. The viewer doesn't
have to think about such things as the fact that in Oklahoma
City, Channel 13's digital channel is 32. He or she just hits
the Program button on their digital converter box or tuner and
it finds all the signals automatically so that when you want to
watch Channel 13's digital channel, you just enter 13.1 and it
knows to switch the actual RF tuner to UHF Channel 32.

>Does anyone know why this is being mandated?  Is there a similar requirement 
>in other countries?

	Oh yes. It is being done all over the world and
several countries are a bit ahead of the United States and some
have yet to start but are thinking about it.

	I read where Mexico is also starting the digital switch
but hasn't set a firm date for switchover.

	As for why? It is true that money is behind the change
but it was going to happen sooner or later.

	It was once said that if we wanted high-definition TV,
it would take about 20 megahertz per channel and there flat
isn't any spectrum available for that kind of bandwidth
anywhere. Japan experimented with analog high-definition
television, but most countries' equivalent of the FCC or
Industry Canada said a firm and emphatic NO to requests for huge
blocks of frequencies and that was way before the explosion of
cell phones and wireless networks.

	Now that we've got digital processing capability that
can create high-def pictures out of information that doesn't
take up any more bandwidth than a standard TV channel, the push
really started. Blame technology advances if you want to blame
anything.

	I think I have seen glimpses of the future right here in
Stillwater, Oklahoma which is a college town about 50 Mines
North of Oklahoma City. In this area, TV channels 9 and 13 are
strong out of Oklahoma City and Tulsa channels 8 and 11 are weak but
receivable. Channels 7, 10 and 12 were virtually empty but would
occasionally have skip signals from other cities in them.

	I have heard a handful of wireless microphones from the
campus in the pass band of Channels 10 and 12. They probably
don't cause any problem since nobody is trying to receive TV on
those channels and the signals from the wireless mikes are only
audible for a few blocks.

	I imagine that some of that VHF spectrum will be used
for these type devices.

	As for Channel 7, it now has the digital version of
Oklahoma City's Channel 5 so it is full of something for now.

	I hope this answers some questions. I do not work in
broadcasting, but majored in it in college so try to follow what
is going on.

Martin McCormick WB5AGZ  Stillwater, OK 
Systems Engineer
OSU Information Technology Department Network Operations Group