When everyone is licensed they should get a free copy of "Yagi Antenna
Design", by the late Jim Lawson. It would eliminated a lot of mistakes and
growing pains..
For instance....
Per Mr. Lawson:
A yagi antenna at 50 feet on 20 meters, would give you two take off
lobes..one at 18 degree's the other at 63 degrees.
Now move the antenna up to one wavelength over ground and now you still have
two lobes, one at 15 degrees and one at 48 degrees.
Now go up to two wavelengths above ground and now you have 4 lobes, one at 7
degrees. one at 20 degrees, one at 37 degrees and the last at 60 degrees.
So, good show on the antenna, but you'll wonder why your neighbor is
opening the band with his 2 wl antenna and you're wondering who he is
talking to, with your 3/4 wl antenna...
What did the wise old "Elmer" say ...Son, put 1/3 of your money into a
tower, a third into the antennas, and a thirds into the radio and
peripheral's
Bill ... KC4PE
http://www.kc4pe.com/amateurshack.htm.
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of David
Gilbert
Sent: Tuesday, October 16, 2012 1:43 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] TowerTalk If you had a choice
And yet, incredibly, the Mosley specs for the Pro 57B say it has 8.5 db
gain over a dipole (dBd) on 20m/17m/15m/12m with only three elements per
band. By comparison, Optibeam claims 8.5 dBd for their 5 element 20m
monobander on a boom twice as long as the Pro 57B.
http://www.mosley-electronics.com/spec%20files/amateur/pro57b.htm
No way on earth that three elements would be capable of 8.5 dBd, but
apparently such unfounded claims sell antennas anyway. I don't dispute
that the Pro 57B is durable, but that's like bringing a 1950's era
Schwinn cruiser to a modern bicycle criterium race.
Dave AB7E
On 10/16/2012 7:08 AM, K7LXC@aol.com wrote:
>> If you had a choice between antennas which would you choose a Mosley
> Pro 57B 3 inch boom or Cubev 4 element 5 band quad. Both would be mounted
at
> 50ft. I do not have modeling software to compare. Thoughts?????
>
> According to our landmark on-the-air tribander test, the Mosley PRO
> antennas underperformed the competition. In one case, it even had
negative gain
> on one band. I'd suggest any antenna over a Mosley.
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|