Eli Polonsky elipolo@earthlink.net
Sun Apr 25 12:45:57 EDT 2010

Eli Polonsky wrote,

>>> From: Jeff Lehmann <jjlehmann@comcast.net>

>> Jeff, I don't think that was what was happening.
>> It acted just like when it's detecting HD on a
>> somewhat distant station that I know is actually
>> in HD, but it can't get a strong enough signal
>> to "load" it completely. Even though I was near
>> the tower, the 5 watt signal (in the null, too)
>> was so weak that I was only getting a few "bars"
>> on the signal strength meter on the display.
> Another possibility:  I don't know if it is the 
> same as with analog, but could you have actually 
> been picking up image overload (whatever the HD 
> equivalent is) from a Pru HD signal(s)?

Image overload, or intermodulation, from strong
but off-frequency HD stations does not seem to 
activate HD at all. Whenever I hear off-frequency
intermod from Pru stations in analog on the unit,
even if it's all coming in very strong, it never 
activates the HD, which appears to respond only
if it is receiving HD on the correct originating
frequency as a clean signal, alone, with nothing
else whatsoever interfering with it. Since image
overload (intermodulation) usually is caused by 
a combination of signals (which you often hear
superimposed on top of one another in analog),
it doesn't activate the HD because it's not 
discerning just one HD that it can "load". It's 
not the same thing as the analog intermodulation 
activating analog stereo pilot lights.

If I'm already listening in HD-only mode, say to 
a multicast HD2 or HD3 station with no analog, 
and the receiver is moved into an area where it 
encounters intermodulation from other stations
overcoming the HD station that I'm listening
to, the receiver will simply go silent and the 
HD light will go off. After a number of seconds,
the receiver may revert to analog mode and I'll
hear the pig-pile of off-frequency stations in
intermodulation, but the HD will not activate 
in that situation regardless of their strength.

Another thing that confirmed to me that the HD
signal causing the light to blink was actually
coming from W242AA was whenever I moved the unit
to where W242AA was coming in even weaker, the 
HD light stopped blinking entirely. The HD light
blinked whenever I moved to where I was getting
the strongest, cleanest analog reception on it,
but still not strong enough to fully "load" it.


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