Re: How will the US local area stations commerate the end of System-M?

In alt.tv.tech.hdtv Albert Manfredi <bert22306@[EMAIL PROTECTED]
> wrote:

| On May 1, 9:26?pm, Bruce Tomlin <bruce#fanboy....@[EMAIL PROTECTED]
> wrote:
| 
|> I'm wondering if this is a coincidence, or if an adjacent analog
channel
|> (even from the same antenna farm) really does make an ATSC station hard
|> to tune in.
|>
|> If this is true, then the shut-off can't come any too soon for me.
| 
| Yup. It's not a coincidence. Analog stations tend to transmit at much
| higher ERP than their digital counterparts, and this was especially
| true in the early days of the transition. So what happens is that
| receivers with less than ideal selectivity, as many of the older
| models are, will detect the strong analog adjacent channel and clamp
| down their AGC. This will then cause the much weaker digital station
| you're tuned to disappear in the noise level.

OTOH, if you put 2 stations on _adjacent_ channels, with the same ERP,
then
they should be fine transmitting from the same tower.

Apparently it takes quite a strong signal to do that.  Even though WPBY-TV
would boom right into my home in my teen to college years, I could still
get WOSU-TV just fine ... weak, but fine ... on a TV made around 1968.
WBPY-TV (then known as WMUL-TV) is on 33, and WOSU-TV is on 34.

Maybe it is the case that today's tuners, being all digital in design even
for analog signals, might have traded off more of the selectivity and are
actually worse.

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