A temporary move to a midcentury modern Eichler home with a flat roof on a very small lot has presented yet another challenge for amateur antenna mounting: non-penetrating roof mounts.
The V/UHF antennas you see here are attached to those mounts, which are normally used for small satellite dishes, grid dishes and commercial verticals:
I'm not having much luck with HF in this location so far. See my previous "flagpole" antenna project if you want to see how well that can work in the right conditions. But I've got reason to be patient: at our permanent QTH across town we're installing a tower! Read on...
For now I'm concentrating on the higher frequencies and am having a ball with VHF/UHF contests, nets and satellites using just the simple omnidirectional antennas you see here. Below you can see how the non-penetrating roof mounts are weighed down with concrete blocks or pavers:
||Above, from left-to-right:
- a Diamond X-200A 2m/70cm vertical,
- a James Pole 23 cm
J-Pole and a set of
Olde Antenna Labs
23 cm stacked "wheels" hanging off an Icom AG-1200 preamp (see detail at left),
- an M2 EB-144 two meter eggbeater,
- A James Pole 220 MHz
J-pole and a set of stacked KU4AB 222 MHz loops,
I purchased these mounts from HomeTech Solutions in Cupertino, CA. For example, in the picture below is a Winegard DS-5046 base and DS-5146 1.66" post kit (they also make DS-5001 2.38" post kit):
Notice the three concete pavers holding it down. I later added a 5 foot mast to give the 2m/70cm vertical more height, even though mount did not affect the SWR. That additional 5 feet was all I needed to reach all repeaters in the area with full quieting.
The 2m/70cm "eggbeaters" wouldn't mind being so close to all that metal either if used just for satellite work (because the bases would probably just help direct their attention upward), but I also use them as horizontally polarized omnidirectional contest/net antennas so I needed put them up higher too. So, for my next trick...
...I put the 70 cm eggbeater and the 6 meter loop on a 10' mast, attaching it to the little mast already on the mount by using parts from two sets of U-bolts to mate the different size masts:
Moving the EB-432 up to the top of the 10' mast increased the horizontally polarized portion of my signal by at least 6 db at the horizon and beyond! And with AEA Halo-6 loop, I have enjoyed regular openings from California to Montana and other similar distances.
Notice that mast is carefully guyed with dacron ropes, so I've only replaced two of the pavers with full-size concrete blocks. They sit atop a structural beam that runs below the roof there.
For the 220 MHz J-pole and 222 stacked loops I put up the same mount-and-mast combination, for similar good results. I logged stations far-and-wide during a recent contest, including a big gun 160+ miles away on 144, 220 and 432. (OK, so he was pointing massive H-frame beam array at me from a tower on top of a mountain. But still, that was really cool.)
The 2 meter eggbeater is performing well atop an NO-103489 Roof Mount with 5' mast, which I think is waaaay overpriced compared to the other mounts:
This mount's included 5' mast is an odd size and the struts at the bottom are in the way, so it is very hard to attach an additional mast unless you're going to use a very light rotor for a very small beam or dipole. Luckily the EB-144 doesn't need as much height as the EB-432 to get out to the horizon.
One more to go: a 927 MHz J-pole I've just ordered from James Pole. Meanwhile, at our permanent QTH across town, we're installing a US Tower MA-40 rotatable telescoping tower for a small stack of beams. Stay tuned!
Antenna Tower Project: MA-40 Rotatable Crank-up
Antenna Farm 3: The Slanted Roof Solution
Flagpole Antenna Project • Antenna Farm 1
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