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small or "mini" beams?

Discussion in 'Home Brew' started by rangelia, Sep 3, 2018.

  1. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    Even the manufacturer does not even state gain figures for that TAK-tenna. All they say is that it presents 10-12 dB of directivity which does not mean 10-12 dB gain. Any antenna that small is going to perform worse than a regular dipole yet due to it's construction will still show directivity. The same thing applies to the ferrite loop-stick antenna used in AM radios. They show great directivity yet have negative gain figures down in the double digits.
    Does the TAK -tenna work? Sure it does but so did my 4 foot helical antenna on 160m. It worked but very poorly. Are there better antennas? Most definitely YES but as always, a poor antenna is much better than no antenna at all.


     
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  2. 2RT307

    2RT307 Sr. Member

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    The other school of thought is, the higher up the antenna, the smaller it looks from the ground. Put a 5 element Yagi up at 60 feet, and it's tiny! :ROFLMAO:

    73,
    Brett
     
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  3. Riverman

    Riverman Old Member

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    Doggone it. You're late to the game, Captain. I'd already put my umbrella away and now I'm soaking wet thanks to you! :eek:

    Actually, you didn't really rain on this parade; you simply reminded us what we already knew and don't like to hear: The morbid truth. :D
     
  4. BJ radionut

    BJ radionut Supporting Member and 6m addict

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    Did somebody call me?

    I love the one video..40-50 db reduction in signal strength between the 88 ft endfed:whistle: and the tank'er..."But see how well it receives" ......Yep it does. That's an old trick used by the big time DX'ers on 80m and 160m ops...They use one antenna, a full size vertical. or very highly elevated dipole or inverted "L" to transmit on, then a very small loop, directional beverage or maybe a Long-wire mounted damn near right on the ground to receive on.
    To help in noise reduction.
    I did not see where they did a transmit test between even those 2 antennas(EF vs Tank'er)...Why? The signal strength on transmit would have had similar results.
    I never say these antennas won't make contacts, Hamsticks prove that even the poorest antenna will make some contacts, but when that occurs, don't get to proud of yourself. Be best to tip your hat to the op on the other end for having a good receive set-up...(y)
    Not to mention the fortitude to pull your sig out of the noise:love::LOL:
    It is all about conditions...One of my favorite sayings on 75 mtr's is:
    "Everyone is loud somewhere"...reality is it may not be the direction your trying to talk!:rolleyes:
    All humor intended!
    All the Best
    Gary
     
  5. Robb

    Robb Yup

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    Better get to the horiz and vert choices. Since this will make a huge difference in what you want to do. Horiz polarization is for real DX contact work; noise is dimished greatly. That is why I suggested a Yagi/horiz.

    If vertical; then DX is not going to be as good or as strong. More noise too, since most noise is man made and is vertically polarized.
     
  6. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    I'm hoping the wife will fall for that. :whistle: I have decided to forego my antenna installation AGAIN this year partly due to a change in plans and partly due to climbing issues. I have had some really bad luck getting things on the tower the past couple years following two separate injuries in different years that prevented me from climbing. I have decided to sell my Explorere-14 with 40m kit as well as my A3WS and but the Hygain TH11DX which will replace both antennas. I will do this NEXT summer. I haven't told the wife just how BIG the TH11DX actually is :sneaky: only that it will be bigger than the Ex-14 but it will take the place of two separate antennas and will be at 62 feet. :)
     
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  7. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    Indeed. Many times I would switch to my tribander to RX on 80m because my inverted L was way too noisy on RX but worked quite well for TX. As for the Hamstick comment......yeah I had a mobile installation one time on my car and was working 75m mobile one night on a long drive home. I worked several station in Virginia, Ohio, Florida and then England. I knew I had a pi&% poor antenna but it was fun to actually make it across the pond on 75m with it and a blistering 100 watts. LOL
     
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  8. Low_Boy

    Low_Boy Sr. Member

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    I also noticed nothing was mentioned about gain. HMMM
     
  9. BJ radionut

    BJ radionut Supporting Member and 6m addict

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    I wasn't going to jump in on your quest for comments on your new choice CK. I had not had any actual experience with the TH11DX, I had the change to operate during a contest quite a few years ago to use a TH7DXX at around 60 ft...Good conditions then yes, but what a excellent performer...it was pretty amazing! I wish you luck and I know it will do well. I'll catch you off board to let you know some personal observations and thoughts on HyGain with my resent build on the 6m VB66DX antenna.
    Where did the summer go!
    Special NOTE to All here:
    I'll let all know here what times, I will be operating, but have been invited to operate during the CQ WW SSB contest in Oct. 2018 from the W8PR contest station.
    I am really looking forward to that!
    All the Best
    Gary


    Check out the setup W8PR on QRZ.com
     
  10. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    I have a friend that has a TH7DX and he loves it. My issue is trying to have as many bands as possible on the tower without having to move the rotator down the tower further. Right now it will be about 5-6 feet below the top but with a very long mast and high wind load it should be 8 feet down. A TH11DX will allow me to eliminate one antenna and mount the highest wind drag antenna directly at the top which will be fine with 6m and 2m yagis above it. Back when I had two good knees and a few less pounds on me I could run up and down the tower or spend all day hanging on it doing work but times have changed and so have circumstances. I used to work hard to save a few $$ and now I have a few more $$ and use it so I don't have to work quite so hard. ;)

    As for Hygain.......I plan to make a few modifications to most antennas in the name of improvement. All my Hygain or Cushcraft antennas have had tubing inserts added at the element to boom mounting points and usually the hose clamps have been upgraded as well.I have also upgraded the 1/4 inch hardware on the EX-14 to 5/16 stainless just because. I just look at it as a small job now to prevent big problems later. You can never go wrong with increasing the strength at the element mounting points or the boom to mast point.
     
  11. StrangeBrew

    StrangeBrew Sr. Member

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    I know you already moved on from the TakTenna but googling "petlowany coil" will bring a little more info for home brewing one.

    Also do a little research on hex beams for another slightly smaller option.
     
  12. Blackcat630

    Blackcat630 Sr. Member

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    Wow.. I checked W8PR out. Hell of a set up. Dude.. enjoy yourself.
     
  13. rangelia

    rangelia Member

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    So if I decide to go the MOXON route, can it be done with 1/2" EMT? Not the "spreaders" but the elements themselves . I would like to do it in copper but Im on a tight budget. So as of now, Im either going to do a vertical dipole (in 3/4 and 1/2" copper for the elements, or a MOXON in 1/2" EMT . Givin my monetary limitations ATM Im not expecting performance out of either. When the time comes, I will build a proper monstrosity.
     
  14. Robb

    Robb Yup

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    Sure, emt, copper, aluminum. The only problem with different metals is the velocity factor. There is no advantage to copper. What ultimately makes the difference is what holds up best in the environment with high winds. Copper loses; aluminum wins. Dunno about emt; but it shouldn't be too bad unless winds and ice are extreme.

    So if you were to hold out a 20 ft piece of either metals horizontally; which ones would sag the most over that given length? Add wind and ice and it is easy to see that aluminum wins.

    People have also made moxons using pvc and wire. I'd use emt too, just because it is the cheapest and cheap is cool if it works out - IMO. That is, if you adjust the length of the material used with the velocity factor, so long as the moxon calculator has that variable in that program.
     
    #44 Robb, Sep 6, 2018
    Last edited: Sep 6, 2018
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  15. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

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    If you use EMT be sure to paint it. The zinc coating is too thin to put outdoors and will be all rusty within a year. The thing about copper is the 90 degree elbows that will solder on and make a strong and RF conductive element. EMT on the other hand has poor connecting fittings that won't stay tight without other support. Any poor connection will introduce capacitance causing the antenna to need constant maintenance unless you plan to weld the EMT together. Or better yet use a conduit bender for the corners. If you are looking for the cheapest route then I would use 12 awg copper wire and PVC pipe. The wire can be tight enough to slightly bow the PVC upwards. The PVC being in the shape of an X to hold the corners of the wire Moxon.
    Chris
     
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