Author Topic: Electrically Shortening/Adjusting a VHf antenna?  (Read 4504 times)

0 Members and 1 Guest are viewing this topic.

GreekMan

  • Prepper
  • Full Member
  • *
  • Posts: 202
  • Karma: 14
  • Gender: Male
    • GreekPreparedness
Electrically Shortening/Adjusting a VHf antenna?
« on: May 23, 2018, 02:10:24 AM »
hi all!

is there a way to "shorten" a VHF dipole or groundplane, but not physically?

Like placing a ferrite bead on the root of the elements?

Tempstar

  • Full Member
  • ***
  • Posts: 372
  • Karma: 23
  • Gender: Male
  • Extra, VE, SC Agency MARS, AUXCOMM, ARES/RACES
Re: Electrically Shortening/Adjusting a VHf antenna?
« Reply #1 on: May 23, 2018, 04:22:03 AM »
Yes, capacitors in the Pf range. I have used a 15pf trimmer cap soldered across the connection at the antenna.
"Preparedness is a lot more than just buying stuff"

GreekMan

  • Prepper
  • Full Member
  • *
  • Posts: 202
  • Karma: 14
  • Gender: Male
    • GreekPreparedness
Re: Electrically Shortening/Adjusting a VHf antenna?
« Reply #2 on: May 23, 2018, 04:42:59 AM »
indeed. I should have thought of it myself.

I guess efficiency will suffer a bit

BTW, at what voltage rating?

Tempstar

  • Full Member
  • ***
  • Posts: 372
  • Karma: 23
  • Gender: Male
  • Extra, VE, SC Agency MARS, AUXCOMM, ARES/RACES
Re: Electrically Shortening/Adjusting a VHf antenna?
« Reply #3 on: May 23, 2018, 06:59:21 PM »
I used 100 volt
"Preparedness is a lot more than just buying stuff"