I appreciate all the comments, however, front end overload doesn't seem to be a condition at my location. I'm about 35 miles from the closest transmitter. There are no stations in the area that are adjacent to the problem channel. Intermodulation, I guess, could be a possibility if it's a condition created by the problem transmitter. Also, I'm not the only one in this area experiencing the indicated random signal loss of this channel. The fact that I have to take the signal down 21 dB in a grade B area is somewhat a mystery. BTW, I have a preamp on my attic antenna, but that is required to receive my weaker channels.
On Jan 15, 2007, at 6:36 PM, Allen Le Roy Limberg wrote:
Front end overload, possibly by nearby channels. This is owing to the AGC design of the receiver, not something to do with the ATSC modulation scheme.Al ----- Original Message ----- From: Barry Brown To: opendtv@xxxxxxxxxxxxx Sent: Monday, January 15, 2007 11:53 AM Subject: [opendtv] Re: Analog v Digital TV On Jan 15, 2007, at 8:57 AM, Craig Birkmaier wrote:Anything downstream in an ATSC transmission is error protection with the sole purpose of trying to get the data in the files I described above to the decoder in the receiver with the lowest number of errors possible. IF you can receive the ATSC transmitted bits perfectly, you can reconstruct the MPEG video stream at the same level of accuracy, as a decoder that is connected to the output of the encoder ( i.e. NO CHANNEL ERRORS).What ATSC signal conditions, other than multi-path errors, would cause some receivers to give an intermittent "Loss of Signal" indication (might be loss of sync) where inserting 21 dB of attenuation in the antenna connection corrects the problem? One channel in my area is such a case. It is not the strongest or weakest channel nor is there any indication of multi-path errors on analog channels (not adjacent) either side of the problem child . In fact one of the analogs is transmitted from the same tower as the DT channel.