Topband: RX 4 square

[Tom McAlee]

> Is anyone willing to share their experience with me concerning DX
Engineering RX 4 square? ... Please send any comments directly to me.

As someone else pointed out, this may be of interest to others so I'll send
it to the group.  Your mileage may vary, but here is what I found...

I installed one of the DX Engineering RX 4 squares last summer, along with 4
of their reversible Beverage systems.  I also had a 4-direction K9AY loop
up.

I built the 4 square using their 80/160 compromise size (98' per side).  It
is approximately 600' from the TX antennas and 400' from the nearest
Beverage, fed with RG11 back to the shack.  I went through ridiculous
extremes to build the antenna precisely, measuring the phasing lines with a
TDR and having a land surveyor mark out the locations for the verticals.  As
one well-known contester pointed out to me, I "precisely built my compromise
antenna".

The beverages are all 580' long with separate RG11 feedlines back to the
shack for each of the 8 directions.  The closest point from any of the
beverages to any TX antenna is about 700'.

I live in a relatively quiet/rural area.  The property the RX antennas are
on borders 1.8 million acres of national forest from west through north to
east.  The Virginia Tech campus is about 4 miles to my south, so there is
some activity in that direction.  But, it is a relatively quiet place.
Drive 10 minutes outside of Blacksburg and you're in the middle of nowhere.

So, that's the setup.  The results probably won't surprise too many people.
The Beverage antennas are almost always better.  There have been rare times,
usually earlier in the evening, before it's fully dark, where the 4 square
has heard an EU station better than my NE Beverage.  But, it's rare and has
yet to be that much of a difference.  In other words, it has never exhibited
better signal-to-noise such that it made the difference between a QSO and no
QSO.  The beverages, on the other hand, have heard things on many occasions
that I probably could not have pulled out on the 4 square.

However, the 4 square often exhibits much better high-angle rejection than a
Beverage.  The path between me and EU covers W1, W2, and W3.  There are a
lot of big stations there and I'm often pointing right at them.  There have
been times when I was working a DX station on 160, then along comes an
obnoxious, loud, clicky, QRMing signal that wipes out the DX on the
Beverage.  I flip to the 4 square and, while perhaps the s/n is slightly
worse than the Beverage, the local QRM drops 40dB and I can copy the DX
station again.  In that respect, it has made the difference between QSO and
no QSO.

Most of my A/B tests have been between the Beverage antennas and the 4
square.  The K9AY loop just doesn't stand up to either (sorry K9AY fans).
For its 25x25' footprint, the K9AY loops were impressive and allowed me to
work DX that would not have been possible listening on the TX antennas.
But, it just didn't compare once the RX 4 square and Beverage antennas were
added.

Keep in mind that although I am suggesting the beverages are overall better
than the 4 square except on rare occasions, the fact that they are even
somewhat close is impressive when you consider the 4 square's size.  My
Beverage wires take up 8 acres.  The 4 square takes up 0.2 acres.

If I were to do it again, I would still install them both.  It's nice to
have that second choice even if I don't choose it often.  Also, since my
Beverage wires are out in the woods where there can be significant damage
due to falling braches and trees after a bad wind storm, it is nice to have
a backup in case a needed DX comes on before I get to fixing the damage.

73,
Tom, NI1N