Hi, Guys. I Must say, I have been viewing a lot of your projects recently, and it's been conjuring up many great ideas in my own mind regarding anttena construction!
To the guy who built the Mclapp with the ice cube trays, I offer my kudos, regardless what some have said.
I must admit, I did have a bit of a chuckle, myself, but I fully understand what you were doing with that idea. In DIY, and in the interest of devising what one might otherwise pay astronomical money for, or for that matter, not be able to obtain commercially, the use of whatever household materials available must be explored. That's what makes all of this so interesting. I thought it was kinda weird, but if it worked, who cares? No one is going to see it that closely way up on your roof, anyway. It's "survival of the slickest," at it's best.- The best part is the cost.
In reference to the guy who had better success using the 11-1/2" whiskers, I, too am interested in Mclapp's findings regarding this. By the way, with the exception of your beige/sand colored shingles, (mine are blue) your roof looks much like mine. I also have multiple antennas, much like yours. Placement nearly identical, too. My Radio Shack Yagi looks a little different than yours, but basically, otherwise, we have the same "motif" on our roofs.
My Radio Shack's "Best"
antenna, higher up, as yours, won't hold a candle to my Mclapp 9-1/2" x 9" about 10 feet lower!
Anyway, I did a little work today in straightening out my phase lines on my reflectorless DBGH, and as soon as we get some less crummy weather we've been having, I can't wait to hoist that sucker up there!
I do have a few concerns regarding it, though.
I noticed on most of the DBGH designs I've seen, that they run the cable line up the back of the mast, attaching a long balun in a way that the leads are back behind everything. My PVC construction incorporated the use of forward facing "stubs" which allowed me to keep the 8 guage phase lines from "flopping around," by attaching them securely to them, in order to maintain a faithful, parallel distance of 2" apart. For this reason, it seemed easiest and best to have the balun attached in front of the antenna and phase lines. Should this affect performance? If this is OK, how far in front of the phase lines should I keep the cable and balun?
While I'm on that subject, I noticed the discussion regarding "sloppy washer placement," and must admit, I'm guilty.
All of my 4-bay Mclapp antennas have this issue, and it's just something I guess I overlooked.
My best Mclapp, a 9-1/2" whisker X 9" spacing has a 2" spacing on the phase lines, which I used very large brass washers, overlapping significantly. When I measure the spacing, the phase lines are exactly 2" apart, but between the washers, they are about 1-1/2" apart. (All 5 pairs) Is the inconsistency in phase line gap seriously impeding it's abilities? In this situation, which phase line gap would it be following according to modeling? (Actual phase line gap, or the gap between the washers?) In other words, is my antenna acting like an antenna with 2" phase line spacing, 1-1/2" spacing, or neither?
I have some updates regarding the channels I've had trouble with. WBRE, (virtual 28), and WYOU (virtual 22) are coming in rock solid, and are easily the strongest stations.- Both VHF high channels (actual 11 and 13, respectively) For whatever reasons, though, however, channel 28 has occasional, brief periods when there is no signal at all, and wondering if this is the station having problems. (Otherwise, it's my strongest station, which makes no sense.
WVIA, virtual 44, PBS affiliate, a multicast channel has 4 channels: 41.1, 41.2, 41.3, & 41.4. Sometimes, only 41.1 works, and comes in also rock solid, but the others do not at all. When they do come in, they are all equally as strong.
Using the 9-1/2" x 9" Mclapp, I am effectively recieving, with few problems or dropouts, (in order of signal strength) 11, 13, 32, 31, and 41. The problem channels are 49 and 45, with 49 being by far, the least reliable. At times it's fair, and others- nothing. Just wondering what Mclapp version might be optimum for focus on channel 49.1 & 49.2 (actual)- virtual 16 WNEP, (ABC affiliate). There was some discussion regarding getting the VHF high channels with the larger Mclapp, as well as different sizes being more optimum on certain UHF channels, while being a comprimise on others. Using this logic, it seems sensible to build an antenna which strategically focuses more towards the weakest channels, in which mine are actual 49 and 45. (repectively)
By the way, because of my awkward location, between mountains, in a valley, and most stations to the SW, with a few others N/NE and N/NW, it seems to be best in my situation to go reflectorless, which is what I'm doing.
Many thanks for your contributions.