Warning: Creating default object from empty value in /homepages/11/d132647312/htdocs/Amfone/mkportal/include/SMF/smf_out.php on line 47
Portable AM'ing antenna




 
The AM Forum
October 23, 2018, 02:04:50 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: Portable AM'ing antenna  (Read 516 times)
0 Members and 1 Guest are viewing this topic.
ka1tdq
Member

Online Online

Posts: 1073


Massachusetts Democrat


« on: June 06, 2018, 11:15:53 PM »

The picture speaks for itself.  It's a 40 meter dipole that installs and disassembles easily.  The support mast is a 3/4" x 10' fiberglass rod which slides into a piece of 3/4" copper tubing.  The wire comes off the center insulator via wing nuts.  The center insulator sits atop the mast by a 3/4" copper cap that's bolted to the center insulator.  

I'm getting 1.5:1 VSWR at 7.293 MHz.  I've tried my Alinco rice box on top of South Mountain (broadcast tower heaven) and it didn't suffer any interference whatsoever.  I want to try this setup this weekend on AM.  An Alinco sounds horrible on AM, but if the setup works ok then I could build something decent for the car.  The caveat being that I need to be very discreet so as not to draw attention to myself.

Jon  


* IMG_0930.jpg (2319.78 KB, 4032x3024 - viewed 128 times.)
Logged

KD6VXI
Contributing
Member
*
Offline Offline

Posts: 1877


Making AM GREAT Again!


« Reply #1 on: June 07, 2018, 12:41:05 AM »

The caveat being that I need to be very discreet so as not to draw attention to myself.

Jon  


Why in the world would you need to do that?

I always thought hamming in public was a good opportunity to 'spread the word' about our hobby.
If you still have a bad taste in your mouth about Vegas, I'm sorry....

I can't imagine living being in fear of my hobby.


--Shane
KD6VXI
Logged
W6TOM
Contributing
Member
*
Offline Offline

Posts: 405


« Reply #2 on: June 07, 2018, 07:31:26 AM »

  Looks good!! I've thought of something similar but in the bed of my pickup using one of those fiberglass painting sticks, what type of fiber glass rod did you use?? My only concern would be the ends of the antenna being contacted by some one. Certainly a lot more efficient than my Outbacker.

  I made a trip in March 2017 to Death Valley, operated with the Outbacker on 80 and 40, was able to check into several nets on 80 and actually worked South Africa on 40 one night. I ran a 65 foot piece off wire back from the antenna base to improve the counter pose.


* Radio Setup Pamamint Valley.JPG (302.64 KB, 1024x768 - viewed 65 times.)
Logged
ka1tdq
Member

Online Online

Posts: 1073


Massachusetts Democrat


« Reply #3 on: June 07, 2018, 08:24:40 AM »

Actually I was joking about being discreet with that monstrosity hanging off the car.

The fiberglass rod came from Grainger for $40. 

I have the mobile bug now.  For 20 meters I have just a short MFJ whip and was able to talk to both stations on the USS Iowa in Los Angeles.  I was just driving down the road too... no mountaintops. 

Efficiency drops in the mud for 40 and 80 meters with those whips, so I decided to dry an inverted V.  It's great that you could check in the way you did with the Outbacker.  It speaks volumes for how good those antennas are. 

Jon
Logged

KD6VXI
Contributing
Member
*
Offline Offline

Posts: 1877


Making AM GREAT Again!


« Reply #4 on: June 07, 2018, 09:54:42 AM »

OK, I took you seriously, Jon.  Like, Vegas maybe....  The aliens....  A probe.....  Anyway, you get my idea LOL!

I did mobile for awhile, it was a ball.  Have. A mosfet powered amp I built does about 800 watts pep.   I worked navassa and a couple other dxpeditions with that setup.  That setup was cool, barely taxed the electric system, etc.

I've also done legal limit mobile.  That's hard. Takes damn near a separate electric system to run the amp.

Glad to hear the aliens didn't get to ya!  LOL

--Shane
KD6VXI
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.046 seconds with 18 queries.