Rick wrote:
. . .The moral of the
story, be careful about making assumptions regarding antenna performance
without having an A-B switch! . .

I'd like to add, use receiving signal strength for comparison. I have a
friend who occasionally entertains himself by asking for comparative
reports for two antennas. The differences are sometimes striking,
especially if the two antennas are described as being very different.
But in reality they're the same antenna.

There are at least two other good reasons for using received signals for
comparison. First, you can average out the effects of QSB, which can be
tens of dB, and can be different or even opposite for two different
antennas. And second, you can, with a step attenuator or an S-meter
calibrated with a step attenuator, accurately tell just how great the
difference is. If someone else truthfully reports a two S unit
difference, you don't have any way to know whether it's 4 dB or 12.

Roy Lewallen, W7EL

So my conclusion is that even though the vertical might have the low angle
pattern, the losses in the soil do not allow the advantages to be realized.
Phased arrays of similar antennas over lossy soil may show the nice pattern
and f/b but the absolute value of gain expected may not be realized.

My experience in MS (clay soil) comparing a dipole (nearly flat-top) at
about 90 feet to verticals is that the verticals nearly always win for dx.
(this is on 3.5 MHz).

However, I usually put down ~50 1/4-wave radials for the verticals.
I would definitely increase the number over 18.

My qth is also surrounded by a large number of large pines. In fact
the verticals I compare to are wires supported by the trees.
I have no idea how much they affect the signal, but verticals still
outperform dipoles for dx at my qth.

Do you have other metal objects or ground clutter (houses, etc) near to
the vertical? What was the feedpoint impedance of the vertical?

Tor
N4OGW

(Rick) wrote in
:

Following is a posting similar to what I made on QRZ.com in reply to a
guy who was asking what kind of antenna to use out west in the
mountains surrounded by tall pines. It summarizes my recent
experiences with a vertical on 80 m here in central New Jersey:

While 4NEC2 is no doubt more accurate than MMANA-GAL barefoot, what I
notice is that an arrray of verticals is usually better in its favored
direction than any dipole below about a half wave.

Now to a more anecdotal discussion. Many years ago, I had an inverted
vee like yours and a pair of Electrospace verticals phased with 16
radials each over Nova Scotia spruce forest type soil. The verticals
clearly outplayed the inverted vee for extreme distances such as the
middle east and VK or ZL. But the UK was more middle distance and mostly
over water. One night Dale (now VE7GL) was testing, for a G2 ham, a
sloper beam array with two steep sloper dipoles mounted either side if a
delta reflector. With the back sloper also tuned as a reflector, these
antennas lay down a very good low-angle pattern. Dale was around 20db
over S9 on the vertical array and around S9 on the vee--according to the
radio I was then using. Lou Varney (G5RV) broke in (using a G5RV) and
mentioned that I was half an S-unit better with him on the vee. I
noticed the same thing at my end. On the vee, Lou was almost equal to
Dale. But on the vertical array, he went down about 3db while Dale came
up about 20db. There was also a noticeable multi-phase quality to both
signals on the vee that disappeared on Dale's signal on the vertical
array.

Now, what I think was happening here was that my vee was picking up a lot
of fairly high angle, multi-hop energy from both stations, while the
verticals were favoring the large low-angle component of Dale's signal.

The moral of the story is that the antennas at both ends need to be
optimum for one another.

Also, verticals do have significant ground losses in all but the most
ideal locations. Raising the vertical(s) several feet above ground and
supplying a resonant wire counterpoise will go a long way to reduce those
losses. Furthermore, even a small active vertical or array can be a very
effective receiving antenna, eliminating a whole lot of near distance QRM
and QRN from your S/N ratio.

Of course back in that day, nothing beat W2HCW's yagi! :-)


--
Dave Oldridge+
VA7CZ
ICQ 1800667