Basic VHF/UHF mobile antenna tuning - The quarter wave whip

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  • Опубликовано: 29 сен 2024

Комментарии • 51

  • @DarrenWinsett
    @DarrenWinsett 3 года назад +3

    I am brand new to all of this and my brain is oozing out of my ears lol I've spent hours staring at this screen learning as much as humanly possible.

    • @survivalcomms
      @survivalcomms  3 года назад +2

      This is the base of antenna theory. Once it clicks everything else will will fall in line. Thanks for watching !

  • @donarnold8268
    @donarnold8268 5 лет назад +1

    Thank you!

  • @ugsisr
    @ugsisr Месяц назад +1

    I have this exact Antenna ...It's a winner for 2 meters Thank You Well done

  • @sangalanga9593
    @sangalanga9593 3 года назад +1

    Hello, I have a mag mount Antenna. It tuned to a certain frequency by factory, I need to replace the whip and my question is which part of the mount is tuned? The whip or the mount?

    • @survivalcomms
      @survivalcomms  3 года назад

      The length of the whip. On an increase in frequency the whip is shortened. In a decrease in frequency the length is increased. Thanks for watching !

  • @jay-rus4437
    @jay-rus4437 4 года назад +2

    Love it. Decided this weekend to go after my amateur license. I dont even own a radio yet, but I started studying yesterday and am taking the license exam this thursday. Ive been going through practice tests since yesterday and am passing every time now at about 80-85%. The last 6 tests I have done have all been passing. Will do another several tests tomorrow, and again wednesday. No study day of the exam. I dont like to cram day of. Am looking at what mobile radio and antenna to get for my first. Im in civil engineering by trade, so I enjoy doing the math like you have shared here. You also used some of the foundation of RF that is on the test anyway 😁

    • @survivalcomms
      @survivalcomms  4 года назад

      You will do great and thank you ! I tell folks if you get over an 80 on 10 practice exams in a row passing is certain. There is no trickery in wording like "always do except" etc. Get a mobile with dual receive ,dual VFO's, dual knobs. Its like two radios in one. You will really enjoy the flexibility. Thanks for watching and good luck on the test !

    • @jay-rus4437
      @jay-rus4437 4 года назад

      SurvivalComms .....any advice or recommendation on a mobile?
      Maybe Icom IC 2730a?

    • @survivalcomms
      @survivalcomms  4 года назад

      @@jay-rus4437 Kenwood TM-V71a

    • @jay-rus4437
      @jay-rus4437 4 года назад

      SurvivalComms ....passed exam saturday. Missed one, so all was good. Installed an ic-2730a in the truck with a roof mounted NMO mount antenna. Just spending time now listening, programming, and learning about the radio. Havent seen any real support locally from clubs. Ive reached out to a couple now, but they havent felt very welcoming really. Could be the covid issues, so maybe they arent up and running so to speak. There is one local guy that I have emailed several times, and he has been reasonably helpful in sharing some info, although he also seems very opinionated and seems to like himself a lot 😂😂😂

    • @AndrewMurphy8383
      @AndrewMurphy8383 4 года назад

      @@survivalcomms can you link were u get these antennas please

  • @OH8STN
    @OH8STN 7 лет назад +1

    Always enjoy and appreciate the antenna lessons

    • @survivalcomms
      @survivalcomms  7 лет назад +1

      Antennas are the most interesting part of radio IMHO. Thanks for watching !

  • @DoRiteFabrication
    @DoRiteFabrication 7 лет назад +1

    I'm tuned now....

    • @survivalcomms
      @survivalcomms  7 лет назад

      You are resonant across the RF spectrum :)

  • @GreekPreparedness
    @GreekPreparedness 7 лет назад +1

    This is on more video, building skills for the non-HAM. nice!

  • @user-sq8xt9gk7u
    @user-sq8xt9gk7u 2 года назад

    Is it possible to cut an antenna for DUAL BAND, say, VHF and UHF amateur bands?

  • @jesusjamescano1939
    @jesusjamescano1939 3 года назад

    Im confuse with the tuning chart on line. I want to tune my larsen mobile antenna with magnetic base. I hook it to an icom base radio IC 2000. Id like to have the 144.23 frequency.I dont know exact lenght to be cut on my antenna.Pls any suggest very much welcome...

    • @survivalcomms
      @survivalcomms  3 года назад

      19.5" cut to 19.75" inches and trim to resonance for a quarter wave

  • @mholman9711
    @mholman9711 4 года назад +1

    Thank you 🙏

    • @survivalcomms
      @survivalcomms  4 года назад

      You are welcome ! Thanks for watching !

  • @SuAmigoElilegal
    @SuAmigoElilegal 3 года назад

    Question. I have a dual antenna whip nagoya. It has 3.5vhf and 5.5 of gain uhf. If i tune the uhf frequencie tona desire, will the gain dimish or be affected and the vhf .

    • @survivalcomms
      @survivalcomms  3 года назад +1

      Yes there is a balance due to harmonic relationship between UHF and VHF when you adjust to resonance. The amount of gain of the design will not change however unless the antenna is considerably taken outside of its design frequency. Thanks for watching !

  • @reynaldotabot
    @reynaldotabot 3 года назад

    im trying to tune my antenna(larsen) but when i put my mobile base into high power the swr went to almost 2.5 and power is more than 100 .what should i do

    • @survivalcomms
      @survivalcomms  3 года назад +1

      Make sure the RF connector is good and that the NMO connection is good. Who made the base and what type of feedline does it have ? Thanks for watching

    • @reynaldotabot
      @reynaldotabot 3 года назад

      Rf connector is good , yaesu

    • @survivalcomms
      @survivalcomms  3 года назад

      @@reynaldotabot I meant the antenna base - is it a mag mount, what manufacturer made the base ? Have you tried another antenna ?

  • @AndrewMurphy8383
    @AndrewMurphy8383 4 года назад

    just get you a vhf swr meter would save u all the math

    • @survivalcomms
      @survivalcomms  4 года назад

      I did use a meter. This is a learning channel - without context there is no knowledge.

    • @AndrewMurphy8383
      @AndrewMurphy8383 4 года назад

      @@survivalcomms i understand but not all are good at using said equpment and use was equlvent to a bird meter and not every body have just syaing use swr meter to skip the math

  • @deadbang241
    @deadbang241 4 года назад

    You don’t mention power !! My swr is low ( 1.2 ) at 25 watts and 3.5 at fifty watts. What do you do with that ??

    • @survivalcomms
      @survivalcomms  4 года назад

      What antenna, mount, and frequency are you using ?

    • @deadbang241
      @deadbang241 4 года назад

      Description
      38 inch with NMO 3/4 inch connector 17 Feet RG58 Cable PL259 Connector and L bracket mounted on a headache rack grounded in 4 places , running a Yeasu FTM 100 DR on the 147 and 440 frequencies

    • @survivalcomms
      @survivalcomms  4 года назад

      @@deadbang241 have you tried a 1/4 wave antenna at either VHF or UHF ?

    • @deadbang241
      @deadbang241 4 года назад

      No, this is a brand new set-up

    • @survivalcomms
      @survivalcomms  4 года назад

      @@deadbang241 Could well be a poor antenna , mount , cable, or RF connector. I would start with isolating the antenna base to the RF connector by putting a 1/4 wave antenna or dummy load on the NMO base Who manufactured the antenna ?

  • @jiujitsuforall8627
    @jiujitsuforall8627 4 года назад

    I'm a newbie at this stuff and I just bought a Nagoya UT-72 19" 144/430Mhz antenna to use with my BF UV-5RM handheld in my truck. There aren't any instructions on HOW to tune this antenna that I could find. Would I tune this the same way you've described or is there a brand-specific method?? Thanks.

    • @survivalcomms
      @survivalcomms  4 года назад

      You would do it the same way. Just start with VHF. Test midrange 146, then test low 144.500, and then high 147.500. then confirm on UHF thanks for watching !