"dave" wrote in message
news
On Mon, 10 Oct 2011 10:59:57 -0700, Wayne wrote:

A few weeks back, I solicited info on a vertical antenna mounted on a
metal patio cover. Here's the story to date.

First, I put up an Outbacker by using a standard automotive rack mount
clamped on the conduit above the metal patio cover. The Outbacker was
installed simply because it was easy to do, and I have one. Results
were similar to what would be expected from an Outbacker mounted on a
car. There was an unacceptable amount of cordless phone interference on
20 meters. Performance was acceptable on 10-15 meters.

Next, I removed the Outbacker and installed a 8.5 foot whip antenna.
The antenna is resonant at 27.8 Mhz with about a 1.1 VSWR. At 28.5 Mhz
the VSWR measures 1.8, and at 24.9 Mhz measures 2.3. Measurements were
taken through about 30 feet of RG-58.

Performance of the whip is quite good on 10 and 12 meters. 12 meter
performance seems better than 10 meters, but it isn't clear that
propagation conditions influenced the outcome.

More experiments will be performed, but so far, so good. The unloaded
whip is a simple way for me to operate on 12 and 10.

Wayne
W5GIE

Vertical antennas work great if you get them a few feet in the air. I
need a second antenna for the higher HF bands, I may try a 102" whip
myself.
-
Didn't mention it, but the top of the patio cover is at about 9 feet. It is
about 16 feet by 25 feet.
The whip is a cb whip that I was going to cut to length on 10m. After
trying it on 10 and 12 through a tuner I decided to keep it as is.
-Wayne
W5GIE