Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: I inherited this magmount. How do I know what band it is for?  (Read 1127 times)
KD5ZKI
Member

Posts: 15




Ignore
« on: January 24, 2012, 06:07:00 AM »

This antenna came off of my grandfather's truck. I got it after he passed away. Had a 2m/70cm radio in his truck. I'm just not sure that the antenna is dual band. How can I tell? I don't have a tuner. Could I use just any SWR meter? I think I have one of those SWR/Power meters. I can hit our local repeater, but I'm scared to talk on it too long, because I don't want to damage anything.
Logged
KI4SDY
Member

Posts: 1452




Ignore
« Reply #1 on: January 24, 2012, 06:35:33 AM »

What does the antenna look like? Try to identify it with some of the ham catalogs that we all get in the mail after licensing. Have someone at your local ham club check it with a UHF/VHF meter, prior to use. You are smart not to transmit on it before you have it checked out.  Grin

However, if he had a dual band radio, I am betting that it is a dual band antenna.  Wink

You would probably get better response if you posted this in the "Mobile Ham" section.  Smiley
« Last Edit: January 24, 2012, 06:37:36 AM by KI4SDY » Logged
WB4LCN
Member

Posts: 134


WWW

Ignore
« Reply #2 on: January 24, 2012, 07:58:01 AM »

If a friend has an antenna analyzer, see what band it's resonant on with that.

dave Wink
Logged

First, make it work, then make it pretty.
Yaesu Rigs: Kenwood TS-480HX, FT-8900R, FTM-350AR (Bluetooth motorcycle mobile), VX-8DR, SB-102 boat anchor (built one as a kid)

Moderate Spock: "Live for a reasonable amount of time and scrape by."
WB6BYU
Member

Posts: 13353




Ignore
« Reply #3 on: January 24, 2012, 08:55:40 AM »

I got a whole bundle of stray antennas at a hamfest.  I just put them on the car
and checked the SWR - if it is reasonably low (around 2 : 1 or better) that is good
enough.  Do this check at the lowest possible power and it won't hurt the rig.

Then compare it with another antenna to see that it actually radiates.  Find a
signal such as a distant repeater where the signal strength is less than full scale
on the meter.  Then try the other antenna - you should be able to see if it is
better or worse.  Obviously if it is a lot worse it isn't a good choice for that band.
Sometimes you find an antenna with a low SWR that is a real dog.

The process is quick and simple, and you learn more about your antennas in the
process.
Logged
KE6WNH
Member

Posts: 128




Ignore
« Reply #4 on: January 24, 2012, 06:00:07 PM »

Did the antenna come with a loading coil in the base? That can determine the resonant frequency as much as the whip can.
Logged
K3WEC
Member

Posts: 260




Ignore
« Reply #5 on: January 25, 2012, 03:50:37 PM »

Transmitting for the time it takes to read SWR isn't going to hurt the radio. 
Logged
K1CJS
Member

Posts: 6046




Ignore
« Reply #6 on: January 27, 2012, 05:43:52 AM »

If it's a simple 19 inch whip antenna, chances are that its good for both 2 meters and 70 cm.  If it has a loading coil at the base, chances are that it's either resonant on either one band or the other, but not both.  I agree that an antenna analyzer is the only way to tell for sure.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!