On 160m, many think they can elevate a vertical 20
ft or so, and use maybe 4-8-10 radials to get good
performance.
It just doesn't work that way.

Read Christman... Read Moxon... In general I agree with you but the
devil is in the details...

denny - k8do

Denny wrote:
On 160m, many think they can elevate a vertical 20
ft or so, and use maybe 4-8-10 radials to get good
performance.
It just doesn't work that way.

Read Christman... Read Moxon... In general I agree with you but the
devil is in the details...

I had a 1/4WL 40m vertical with 8 elevated 1/4WL
radials sloping from 20 ft to 5 feet above ground.
At no time or distance did the vertical ever beat
the one-wavelength dipole in the general directions
of the dipole's maximum gain. I assumed it was because
the radials were not high enough and not horizontal.
--
73, Cecil http://www.w5dxp.com

wrote
The only problem is I see no direct comparisons to a normal set
of buried radials. Only that they were able to meet the "minimums"
required by the FCC. I would be curious to see how well the 6 radial
setup would compare to a non crippled set of 120 radials.
It's interesting, and I'd already seen it, but I'm not really convinced
thats it's equal to 120 radials in the ground.
_______________

The FCC minimums depend on the class of AM station.

1) 362 mV/m/kW at 1 km for Class As (equivalent to 225 mV/m/kW
at 1 mile for Class Is),

2) 282 mV/m/kW at 1 km for Class Bs (equivalent to 175 mV/m/kW
at 1 mile for Class IIs and Class IIIs), and

3) 241 mV/m/kW at 1 km for Class Cs (equivalent to 150 mV/m/kW
at 1 mile for Class IVs).

The groundwave field of a perfect 1/4-wave monopole over a perfect ground
plane is about 313 mV/m at 1 km for 1 kW of applied power.

RF

"Cecil Moore" wrote in message
et...
Denny wrote:
On 160m, many think they can elevate a vertical 20
ft or so, and use maybe 4-8-10 radials to get good
performance.
It just doesn't work that way.

Read Christman... Read Moxon... In general I agree with you but the
devil is in the details...

I had a 1/4WL 40m vertical with 8 elevated 1/4WL
radials sloping from 20 ft to 5 feet above ground.
At no time or distance did the vertical ever beat
the one-wavelength dipole in the general directions
of the dipole's maximum gain. I assumed it was because
the radials were not high enough and not horizontal.
--
73, Cecil http://www.w5dxp.com

This is almost (I had 4 radials) identical to what I once tried on 40. Also
had an inverted V at about 45 feet at the same time. In making A/B
comparisons with people 300 and 1000 miles away, those with verticals
thought my vertical was better; those with dipoles thought the inverted V
was better. Go figure. I no longer have the vertical.

Tam/WB2TT

(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