Bert - I don't think your specific case provides very much insight regarding the effectiveness of ATSC broadcasting on VHF-HI channels. As I understand it, you have two antennas, an Antennas Direct DB4 and a Radio Shack double bowtie over screen. Antennas Direct claims the DB4 has almost 14 dB gain for UHF channels. They make no claim as to gain at high VHF. Channel Master, which makes both 2-bay and 4-bay bowtie-over-screen antennas, says they are UHF only and lists the VHF-HI gain as "N/A". For viewers who need to receive both UHF and high VHF channels they offer a Digital Advantage antenna, essentially a UHF corner antenna with gain that has a VHF dipole grafted on the back. The high VHF gain is only 2 dB at best and it's non-directional (as you would expect). The addition of the VHF-HI dipole increases the antenna width to 47 inches, compared to their UHF bowtie-over-screen antennas that are only 25 inches wide. So what you have are antennas with elements that are too short for the high VHF band, that probably have negative gain at VHF-HI frequencies; which therefore don't work well (or at all) for receiving high VHF stations. Why does the failure of these antennas to receive channels 7 and 9 for you indicate that the stations' power levels are too low? I'm actually sort of surprised that you could receive WUSA at all with your setup. Jim Albro ----- Original Message ----- From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx> To: <opendtv@xxxxxxxxxxxxx> Sent: Sunday, June 14, 2009 6:09 PM Subject: [opendtv] Re: Transition report > Just as I have been fretting. The draconian power cut, when moving to > digital VHF, was simply too great. I have two updates, one of them from across the pond. Given that my one problematic channel, ABC7, which moved back to VHF, was pixellating continuously, the problem seemed to be a slight deficit in signal margin. The one really nice thing about using indoor antennas, if that's even an option, is that you can mess with them easily. So, in the downstairs system which uses the AntennasDirect antenna farm, I figured that the reflectors incorporated with the quad dipole stacks were simply too close, and too small, to be of much help for VHF. Simple test: just prop up two cookie sheets, side by side, some distance behind the antenna, to act as a VHF reflector. And now ABC7 comes in. Almost perfectly solid. (But of course, without spousal approval.) I didn't try upstairs, but I expect the same result. The Radio Shack double bowtie does not have a VHF reflector. (In truth, even its UHF reflector is too close to be valid, I think.) Still, the simple fact is that when ABC7 was UHF, they had built in enough signal margin to make it quite robust EVEN for indoor recpetion. When they went down to VHF, they expected some sort of propagation miracle from the lower frequency, and the miracle didn't materialize. Surpise. So they are forcing people to install a more complicated antenna system than they could get by with when the signal was UHF. That's plain silly. As timing would have it, Rome (the real one) is going through the same thing now. But not all of stations at the same time. Anyway, it turns out that there too, they expect miracles. Whereas the analog stations were duplicated on top of two hills, one to the South and one to the North, the digital multilexes are split, half from one hill, half from the other. The main RAI channels are unfortunately only available from the hill way to the South, or so I gather from their web site. So I figured no way would my mom and sister be able to use their existing antennas, in their respective apartments. And in fact, they couldn't. My mom was already was using an outdoor antenna, it was pointing to the close-by hill. My sister used rabbit ears. So what did they do? They called an "antennista." In my mom's apartment, he reaimed the antenna, presumably to the hill to the South. And in my sister's, he repaired the outdoor antenna that had already been installed, but was not being used. So that's the way these things are really done, as opposed to the hype about paper clips. The same problems cropped up here and there. Bert ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line. ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.