[ETS/PARC List] Why Six Meters??

[Pete Fierro]

I brought this up from the group files section for our new members. Enjoy.
So why 6 FM?

6 meters explained

Well for one thing, the 6m band is under utilized and it happens to be a
band that I love and would never want to loose. For another, there is an
abundance of used commercial equipment around at bargain prices, some even
free for the asking.

Also, for those that are more familiar with a 2m and 440 repeater systems,
you already know that 2 meters provides better coverage than 440. Well a 6
meter repeater, for same antenna height, gain and EIRP will yield better
coverage than a 2 meter repeater.
In addition, the lower frequency range of 6 meters will allow much deeper
coverage into fringe areas. This is of special interest when one is mobile.

As was mentioned above, using 6 meters is somewhat different that 2 meters.
First of all it is at approximately one third the frequency of 2 meters.
This means that the wavelength will be 3 times as long. Most importantly,
this means that a short rubber duck will work worse on 6 meters than a
similarly-sized rubber duck will work on 2 meters.
This also means that, from inside a car or vehicle, 6 meters won't work as
well as 2 meters (which, if you have been on the receiving end of someone
running mobile with an in-car antenna, you know doesn't work very well,
either!).
So basically we are talking outside antenna on the vehicle. Don't get me
wrong, a portable, a.k.a. HT on 6m is great, but you need a large 12 inch
or long rubber duckie, Which is not a good length in a vehicle. The upshot
of this is that 6 meters isn't really a handy-talkie/rubber duck sort of
band.

Where 6 meters really shines is its range.

So once you have gone through the trouble of putting up/using a half-decent
6 meter antenna (a quarter-wave ground plane, J-pole, Hy-Gain V-6R,
Dominator or other suitable antennas  you'll notice that 6 meters can carry
quite a bit farther than 2 meters can for the same power level and height
and gain antenna.

There are several reasons for this fact.
The most obvious reason is that there is a decrease in what is called
"apparent path loss" at the lower frequency of 6 meters, as compared with 2
meters. Given two stations - on a 6 meters and one on 2 meters - identical
stations in terms of receive sensitivity and transmit power and that they
are both using quarter-wave ground plane antennas, the 6 meter station will
have a signal that is nearly 10db (that's 10 times) stronger than the 2
meter station!
If you compare 6 meters to 70cm, the difference is approximately 20db
(that's 100 times!)

Another major reason for 6 meters carrying farther is that it propagates
differently.
In many cases it can seem to get over mountains better (using various
propagation modes such as knife-edge and diffraction.) Finally, it is much
less affected by absorption of foliage than 2 meters and especially as on
70cm.
These improvements come at a price, however as 6 meter antennas are quite a
bit larger than their 2 meter counterparts. Also, 6 meter operation is also
more likely to cause TVI (Television Interference) than either 2 meters or
70 cm (especially to channel 2.)
Since the DTV transition, many stations vacated the Lower Tv VHF spectrum
for UHF so in reality there will now be less interference from the 6 meter
band. However if you live in the Philadelphia area beware of a new digital
TV channel 2 which came to the area when Channel 3 moved to UHF. This
transmitter can trash your receiver if you are in close proximity.
6 meters is also more likely to be affected by power line noise than 2
meters on receive. As you should know, power line noise that is getting
into your receiver locally is not transmitted to the other end. This is
where a good commercial radio with a noise blanker would come in handy.

Another factor that you may (or may not) consider to be a disadvantage is
that 6 meters has band openings. When 6 meters is open, it is much like 10
meters in that low power can allow you to work all over.

Openings on 6 meters recently are less frequent that those on 10 meters and
there are fewer people on the band. You will be amazed at the distance some
stations may be from the repeater during the April-September Sporatic-E
seasons.

Yet another reason for choosing 6 meters was that since the band is under
used and has almost no LIDS on it and those that want to use such a system
will come to 6m.... just as they said in "Field of Dreams"..... build it
and they will come.