[opendtv] Re: ATSC XMTR/RECV compatibility issue?
- From: "Mark Aitken \(Work @ Home\)" <maitken@xxxxxxxxxx>
- To: <opendtv@xxxxxxxxxxxxx>
- Date: Tue, 20 Feb 2007 07:25:15 -0500
The 2150 site you reference is quite inaccurate. If you take Baltimore (for
example), WNUV is shown at its (real) old STA power (we are licensed for a
maximized power), and our FOX station (WBFF, another maximized power station)
is not even shown! Just beware...
----- Original Message -----
From: Richard Hollandsworth
To: opendtv@xxxxxxxxxxxxx
Sent: Monday, February 19, 2007 3:46 AM
Subject: [opendtv] Re: ATSC XMTR/RECV compatibility issue?
Plug your location into www.fccinfo.com (first FM then TV) and also
http://www.2150.com/broadcast/default.asp (to see location on a map). How
close are the nearest FM and TV towers???? [Would you care to share your
location to nearest mile or so???]
I was surprised to see that there are TV and FM stations scattered all across
the Great Dismal Swamp....
Strong station(s) will cause intermodulation distortion products that willl
be stronger on some channel positions than others, which can desensitize the
sensitivity of the HDTV and/or Preamp. Inserting attenuation (whether cable,
splitter or other device) will reduce the intermod levels 3 dB for every 1 dB
of attenuation. Which could explain why it works better with more attenuation.
holl_ands
=============================================
Barry Brown <barrysb@xxxxxxxxxxx> wrote:
Bert,
There isn't an adjacent high power analog but a 2.6 MW one channel
removed transmitting essentially from the same antenna farm. Any
chance that this could cause the problem?
Barry
On Feb 18, 2007, at 7:35 PM, Manfredi, Albert E wrote:
> Barry Brown wrote:
>
>> I posted here about a month ago, indicating the reception of
>> the problem station was unstable, continuous pixillation,
>> stuttering sound, picture freezes, and error message reports
>> indicating "Loss of Signal". I also reported that this was
>> not an overload condition as the station is not the
>> strongest in my area. Also, it didn't appear due to multipath
>> errors as the images from analog stations nearby the
>> transmitting frequency of the DTV station were ghost free. I
>> reported that inserting a large amount of attenuation in the
>> antenna feed did, in fact, stabilize the receiver.
>
> Did you go to http://www.fcc.gov/mb/video/tvq.html to see whether
> there
> are strong adjacent (in frequency) analog stations to the problem ATSC
> station? It could be that the attenuator is helping by attenuating the
> analog signal. What you describe is pretty much the way I now receive
> WETA-DT, on the TV that uses the outdoor antennas. With an indoor
> antenna, instead, it comes in fine. The reason? WETA-TV, at 2.3 MW
> ERP,
> Channel 26, is next to WETA-DT, at either 75 or 90 KW ERP, Channel 27.
> I'm guessing that 3rd gen receivers have a particularly tough time
> with
> this.
>
> As to other causes, I would not assume that good analog reception
> always
> translates to good digital. I did an experiment just the other day,
> right after freezing rain had left behind a thick coating of ice.
> Several digital stations became more difficult to receive with my
> larger
> outdoor antenna, but okay with the smaller one, which is aimed
> closer to
> North. Then I tried analog TV. It was entirely the opposite. The
> smaller
> antenna gave lower signal strength and grainier images for all
> stations
> but one, in analog, and the larger antenna was instead providing a
> strong signal, with some typical ghost in some cases.
>
> All returned to normal that same day. My assumption is that ghost is a
> problem, with 3rd gen receivers especially, even if the strong analog
> signal is quite watchable. The ice may have contributed to more
> powerful
> ghost images.
>
> Bert
>
------------------------------------------------------------------------------
Looking for earth-friendly autos?
Browse Top Cars by "Green Rating" at Yahoo! Autos' Green Center.
Other related posts:
