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Foundations of Amateur Radio - Episode 117

Discussion in 'Amateur Radio News' started by VK6FLAB, Aug 31, 2017.

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  1. KM4DYX

    KM4DYX XML Subscriber QRZ Page

    Thanks for that, Greg. I got a little bit of education, here and there, over the past 50 years or so. Learned a little about radio along the way.

    You are right, the analyzer is just a tool. And Ham radio is pretty much just a hobby.

    And, while book learning is great, practical experience in the real world building antennas is how the real learning takes place.

    Have a great day.

    73,
    Al
     
    KK5R likes this.
  2. OH2FFY

    OH2FFY Subscriber QRZ Page

    My last comment wasn't about you :) , this is all in relation to beginner Hams.
    Would a new Ham benefit from an antenna analyzer - probably not.


    And a backward approach to education is why most Hams have poor performing stations.

    Yeah , , actually - NO.
    I don't agree with that.

    Unless we suck off the brains of someone else that knows , it is unlikely that a Ham will be able to understand antennas and use an analyzer correctly , and achieve good results.
    When people say practical learning is best , this practical is usually accompanied by mentoring from others , or technical information gained through other sources.
    So it never is really JUST practical , there is a foundation of theory involved.

    Apprentices go to school for some time before being let loose in the practical world.

    Just bumbling along randomly trying stuff is not learning ,, no matter how fancy our tools are.


    gregW:) OH2FFY
     
  3. KM4DYX

    KM4DYX XML Subscriber QRZ Page

    Well, Greg, I guess we'll just have to agree to disagree. I think an antenna analyzer is a must have tool for any Ham.

    73,
    Al
     
    KK5R likes this.
  4. OH2FFY

    OH2FFY Subscriber QRZ Page


    And without education it will be as much use as a iPad for a baby.

    baby-ipad.jpg



    gregW:) OH2FFY
     
  5. VK4SDD

    VK4SDD Platinum Subscriber Platinum Subscriber QRZ Page


    I could not agree more with the above post. How many times have we heard " the swr is 1.1:1 I must have a perfect antenna" . My 50 ohm dummy load is also 1.1:1 not such a good antenna!!! :)
     
    VK2WP, VK6NO and OH2FFY like this.
  6. AF4RK

    AF4RK Premium Subscriber QRZ Page

    I read an article on Electronic Design News website (edn.com) for professional engineers that used Quantum mechanics and the theory of relativity to prove that the 1/2 wave dipole is the Gold Standard of antennas! I'm not an engineer but I enjoy learning the "real" stuff, and not the watered-down ham radio version. Thanks for your comment, perhaps there is intelligent life on earth.
    AF4RK
     
  7. KD5LRQ

    KD5LRQ Ham Member QRZ Page

    Pretty new to this DX thing. Went and bought a G5RV, hung it from the corner of my 2-story house about 18' off the ground in an inverted V. Proceeded to QSO Canada and Chile and many others the first week on 20M and 40M.
     
  8. DU3LA

    DU3LA Ham Member QRZ Page

    I now have a home brew 40mtr dipole at 65 feet, on my tower in the Philippines and hear far more stations then the old 1/4 wave noise catcher! The RBN spots have also been a lot stronger on CW/RTTY. During contest it is usually one call contacts on 40mtrs using 100watts!
    The only trick about dipoles is to get them high enough, you are looking at about 130 feet on 80mtrs and top band is out of the question for most hams.
    Back to the verticals on 80/160, with rec antennas.
     
    Last edited: Sep 12, 2017
  9. WA2GSL

    WA2GSL XML Subscriber QRZ Page

    e rimp
    Huh? Ground mounted verticals with sufficient radials, IMO 16 bare minimum, 32 better, 48 better, 64 even better but not that much over 48, have proven to be one of the best antennas for small spaces and one of the best DX antennas besides a directional antenna. Verticals need to be as clear as possible. My Windom and dipoles are noisey and can be very noisey. My vertical, ground, mounted 100 feet from my house is almost as quiet as my delata loop. It loads on 6 meters 1.9:1 and has made contacts 2500 miles away on 100 watts. I routinely get through pile ups on 100 watts all over the world on HF with it. I long ago stopped listening to all the antenna modelers and "guru's". Recently a fellow ham was looking to go portable in the woods where his camp is. I threw together a fan 20/40 dipole quickly. We put it 5-7 feet off the ground, (because we only had a step stool) yes 5-7 feet and fed it with RG6 with F-connectors and PL259-F adapters (there's a couple db loss in theory anyway) because neither of us had any PL259's left at the time and I intend to never buy another one (more on that later). AHHHHHHHH! Horror of horrors! This can't possibly work! Model it! The tuner in the IC7300 liked it and 2 hours and 11 countries later on 20 meters we deemed it a success. It now sits about 30 feet up and works just fine so we haven't even bothered to feed it with 50 ohm cable yet. IMO one of the biggest mistakes new hams make is using old technology to connect to antennas. The loss from poorly soldered PL-259's can be astounding. My most recent experience was a drop in power of 50-75% and a increase in SWR from 1.5 to over 10:1 or more. This was caused by what appeared to be a properly soldered PL-259 that had been in service for over a year at less than 300 watts on the indoor side of the antenna and without any previous issues. I have gone 100% crimp connectors. The connectors I use are crimp braid, solder center. The perfect match IMO since crimped center conductors unless done perfectly can actually break behind the crimp point or have a less than optimum connection. With crimp/solder connnectors you get 100% braid contact and a just as good as PL259 center conductor connections. The chance of heat damage to the dielectric is eliminated and the process is quick and easy. The connectors don't cost any more than the ancient PL259 and all I do on the outdoor ends is use liquid tape to seal the crimp furell. Crimping pliers cost maybe $34.00 with one die set and you'll never have to buy them twice and dies for all cables that we use are available for under $20.00. I personally use RG8X cable since IMO the bigger cables at lower power are not worth the extra expense unless you plan on going big power in the near future. Using at least LMR240 or RG8X cable and staying away from cheaper RG58 cables you find at bargain sales and using crimp/solder connectors will keep the noise as low as it can be in your area and the connectios solid to get the most power out to the antenna. All that said one should take great care in building their antennas. Measure twice, cut once, leave room to go around the insulators and maintain proper length on wire antennas. Feed it properly. No connection is "good enuf". Electrically "solid" connections are the only acceptable connections. Protect the connection!! Use Liquid Electrical Tape on the connections including the coax connectors that may be outside. It isn't hard to get off if necessary. Once you've had water infiltration, if you don't do this now you will, so just do it to start with. Don't worry about Elmer and crimp connectors. Some people can't accept change. And most important HAVE FUN!
     
    Last edited: Sep 14, 2017
  10. VK6APZ

    VK6APZ Premium Subscriber QRZ Page

    I have been using the ancient PL259 connectors for 40 years now and never had a bad connection.
    The reason hams are having problems with them now is because they are rubbish, unlike the good old silver plated ones.

    VK6APZ Pete.
     
    VK6ATS likes this.

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