I am trying to calculate how much power I am allowed to run to operate
on 60 meters. Here are the two antennas:

1) 80 meter dipole 129 feet long. The antenna is fed with cable TV
coax with only the following markings: E83032 F6SSVV (UL) CATV
There is no balun on the line. Just the 75 feet of coax from the back
of my tuner to the antenna. The tuner is fed with RG-8X-95 coax 3
feet long.

2) Antenna Specialists 75 meter mobile whip antenna. The windings
will be removed until it matches on the center 60 meter frequency.
The antenna will be mounted on a mag-mount on the top of a Ford
Aspire.

I tried modeling the dipole using ARRL-EZNEC. I modified one of their
dipoles so I get the extra segments. Here is what I have done so far:

Wires: 1) 0, -64.5,50,-,0,64.5,50,-,14,55
Sources: 1 @ 50%
Loads 0,
Xmission line 0
Ground type: Free Space
Wire Loss: Copper
Units: Feet
Plot Type: Azimuth
Elevation angle: 15
Step size: 1 deg
Ref level: 2.15 (dipole as per ARRL Handbook)
Alt SWR Z0: 75

Here are the results as I read them:
SWR Plot: 5.33 - 5.4 step .005
50 ohms, SWR is 59.8 - 62.6
75 ohms: SWR is 40-41.9

When I view the far field plot, it says at the bottom of the main
window, Average gain - .983, = -.07 db Model Contains Loss

With the mininec ground, I get an average gain of .764 = -1.17 db

I haven't accounted for the coax. I tried adding it but the program
froze up and I had to start over.

From what I hear, rumor among hams is that mobil antennas can run over
100 watts and still not violate the erp allowed on the band.

I plan to replace that antenna with a 135 foot wire fed with 300 ohm
TV twin lead into my tuner direct.

Can anyone tell me the highest legal power output I can use to operate
on 60 meters with these antennas?

Thank you,
Buck
N4PGW



--
73 for now
Buck
N4PGW

On Wed, 22 Jun 2005 08:41:47 -0700, Roy Lewallen
wrote:

Please update your program by going to http://eznec.com/eznec_arrl.htm,
where you'll find a link to download the update. If you encounter the
problem after updating, please email me.


I keep getting an error: This program is only for use with EZW 3.0



--
73 for now
Buck
N4PGW

Buck wrote:
On Wed, 22 Jun 2005 08:41:47 -0700, Roy Lewallen
wrote:


Please update your program by going to http://eznec.com/eznec_arrl.htm,
where you'll find a link to download the update. If you encounter the
problem after updating, please email me.



I keep getting an error: This program is only for use with EZW 3.0

That's very strange, and something I don't understand. Please email me
so we can resolve this via email.

Roy Lewallen, W7EL

On Wed, 22 Jun 2005 09:39:15 -0400, Buck wrote:

I am trying to calculate how much power I am allowed to run to operate
on 60 meters. Here are the two antennas:

1) 80 meter dipole 129 feet long. The antenna is fed with cable TV
coax with only the following markings: E83032 F6SSVV (UL) CATV
There is no balun on the line. Just the 75 feet of coax from the back
of my tuner to the antenna. The tuner is fed with RG-8X-95 coax 3
feet long.

2) Antenna Specialists 75 meter mobile whip antenna. The windings
will be removed until it matches on the center 60 meter frequency.
The antenna will be mounted on a mag-mount on the top of a Ford
Aspire.

FWIW:

1) I doubt this antenna system shows any gain on 60m, most dipoles of
this construction wont when operated off resonance. With only 3 db of
loss you can safely run 100 watts, Just tune up and go.

2) Antenna Efficiency is so low on HF mobile antennas 100w will not exceed
the 50w EIRP limits.

--
Korbin Dallas
The name was changed to protect the guilty.

That's very strange, and something I don't understand. Please email me
so we can resolve this via email.

Roy Lewallen, W7EL

Thank you.

--
73 for now
Buck
N4PGW