Here's a follow-up on my post a few weeks ago about reception problems post-repack (see last page)...
On Saturday, I took down my old setup and put up a new one.
The old setup consisted of a Winegard HD6065 FM yagi on the bottom, with a (now dead) NTE U-105 rotator above it turning an Antennas Direct Clearstream 4 for UHF. It worked good at first, but I've had declining reception for years, which I assume is due to tree growth. WMUR became unwatchable. And after the repack I started experiencing frequent artifacts and dropouts on most of the Boston UHF stations, and lost WGBH HD (and WGBX HD) entirely.
The new setup I installed consists of a Channel Master CM-4228HD on the bottom, AD Clearstream 5 on the top, in fixed positions on a new 10' mast with just under 4' in between them. Their outputs are connected to an AD combiner mounted between them on the mast, followed by a AD Clearstream Juice amp.
WMUR is the weakest of all the channels we wanted to receive, because in that direction we're shadowed by the top of the hill we live on. Evey bit of height seemed to improve reception, so I put the CS5 at the top of the mast. Pointing the antenna directly at WMUR leaves WENH only 15 deg from the null in the side of the antenna pattern, but WENH is strong enough that I can still receive it without issue.
To my amazement, when I first connected the CM-4228HD and pointed it South, I was able to pull in WGBH 2.1 on RF5, albeit not well enough to be watchable. The CM-4228HD is a UHF antenna that claims to have some moderate gain in VHF High, so I was pleasantly surprised. It does have a large, electrically contiguous reflector, and I guess that's enough to create a positive front to back ratio even in VHF Low. When I added the amplifier, WGBH became watchable but with frequent artifacts and some momentary drop-outs. The signal quality measured by my HDHomeRun tuner was swinging back and forth, and I suspected multipath, so I experimented with pointing direction and was able to get a fairly stable signal with the antenna pointed Southwest. WGBH is now watchable with no dropouts and occasional minor artifacts.
A few notes on the products for those who might be interested in them:
- The AD Clearstream 5 is surprisingly compact. It could be used indoors pointing out a window. It was very easy to assemble, and doesn't create much of a wind load.
- The CS5 claims to have a small amount of gain in low UHF, but it wasn't enough to receive RF23 (located North) unless pointed precisely, which degrades WMUR.
- The CM-4228HD comes assembled and all you need to do is tighten wing nuts and attach the mast mounts. However, I did have to bend some of the bowtie elements into their proper position because some of them were a little off out of the box.
- For UHF, the 4228HD is a small improvement over my old Clearstream 4. Without the amplifier, I did see slight improvements in signal strength on some of the Boston UHF stations, and fewer artifacts. But I probably would have been OK on UHF if I had kept the CS4 and just added the amplifier. The real surprise with the CM-4228HD was on VHF.
- I chose the CS Juice preamp based on measurements posted by user Calaveras, and I'm happy with it. I saw big gains in signal strength and signal quality on RF5, which wouldn't be watchable without it. I also saw significant gains on RF9 and RF11. The Boston UHF stations were already coming in fairly strong without the amp, so I didn't see significant gains there, but the combination of 4228HD and Juice preamp has eliminated artifacts and dropouts on those stations.
- Last but not least, I used 1-1/4" EMT for the mast, which just fit into my existing tripod. It is larger in diameter, thicker, and stiffer than the 1-1/4" antenna mast pipe I was using before. However, both antennas are a little on the heavy side, with the 8 lb. CS5 mounted at the end of the 10 foot mast. My house is protected from strong, gusty winds because it's surrounded by tall oak trees. But if I were out in the open, I don't think the tripod roof mount would be secure enough.
Pictures to come.