Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
PSA
Member Login

Site Notices
Posted: 10/26/2010 4:43:44 PM EDT
This is on a mobile unit.  I hooked up my swr meter to my FT2900 and the Hustler antenna I have mounted on the truck.  It measures 2.5 in the middle of the band (2M).  I ran the antenna up as far as I could.  It measures 2.5.  I ran it down as far as I could.  The same again.  At first, I thought the meter was a POS, but I hooked it up to my Diamond base antenna, and it measured 1.1.  Just like the book said it would.  

Any ideas on what I can do to get it lower?  It's basically a S.S. whip.
Link Posted: 10/26/2010 4:49:17 PM EDT
Where and how is the antenna mounted to the truck?     any more specifics on the antenna??

Link Posted: 10/26/2010 5:07:22 PM EDT
It's a Hustler SF-2 antenna.  5/8 wave.

I have it mounted in a stake hole mount, near the cab on the drivers side.

I made sure it was well grounded.  I used 10 ga. wire for the ground.

I used RG8x ultra for the coax.

What else can I tell you?

Oh, I made my measurements using 10W.
Link Posted: 10/26/2010 5:15:02 PM EDT
measure it will your door closed,

move it to another location to verify..  the antenna may be messed up..  shorted, corroded..
Link Posted: 10/26/2010 5:18:46 PM EDT
Originally Posted By 338winmag:
It's a Hustler SF-2 antenna.  5/8 wave.


Is that the one with the screw on stinger at the top?   If it is, I think I has to be trimmed based on the specifics of the install....

Link Posted: 10/26/2010 6:30:27 PM EDT
[Last Edit: 10/26/2010 11:28:15 PM EDT by Gamma762]
Antenna not adjusted correctly.
Incorrect or defective antenna.
Incorrect or defective mount.
Shorted coax at the connector or mount.
Broken coax at any point.
Antenna installed in a location that alters the tuning/resonance of the antenna.

Do you have any other parts/antennas you can use for comparison/testing?  Are you testing with a power meter or an analyzer?

FWIW, would recommend moving the mount back toward the rear to get away from the interaction with the cab.  If you're using bare copper wire for your "ground" connection, get rid of that ASAP as you'll get corrosion from the bare copper.  Depending on how the mount is made you probably have plenty of capacitive coupling to the vehicle, if not a small piece of aluminum or stainless wire will be plenty.

Originally Posted By Mndless:
Originally Posted By 338winmag:
It's a Hustler SF-2 antenna.  5/8 wave.

Is that the one with the screw on stinger at the top?   If it is, I think I has to be trimmed based on the specifics of the install....

I don't own one but from the info I can find it looks like it is a tunable antenna, yes.  If you got the antenna new there is probably a cutting chart that came with it, see if your whip length is in the neighborhood of what the chart says.
Link Posted: 10/27/2010 5:09:53 AM EDT
I checked the internet and found a formula for figuring out the length of the antenna.  I ended up with 48".  So, tonight I'll break out the tape measure and see if I can get some better readings on it.  According to the factory, I should be getting 1.2:1.
Link Posted: 10/27/2010 8:25:32 AM EDT
Originally Posted By 338winmag:
I checked the internet and found a formula for figuring out the length of the antenna.  I ended up with 48".  So, tonight I'll break out the tape measure and see if I can get some better readings on it.  According to the factory, I should be getting 1.2:1.

Make sure that formula is for that particular model of antenna.  Differences in the matching coils between different manufacturers means that there is no length or formula that works with all 5/8 wave antennas.  Tuning will also vary slightly depending on the installation of the antenna.  Remember, you can always cut off more whip but can't put any back on.
Link Posted: 10/27/2010 2:22:02 PM EDT
Originally Posted By themcfarland:
measure it will your door closed,



I have seen an open door do this. I cleaned up some installs for a local pd that the tech tuned the antennas with the doors open and had a totally different reading with them closed. And this was the tech that used a wire tap to power a mobile radio and the tech and pd could not figure why in the summer they kept blowing fuses....
Top Top