advice wanted HF antenna for treeless backyard

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by AF5UP, Mar 20, 2016.

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  1. AF5UP

    AF5UP Ham Member QRZ Page

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    Greetings,

    I am a new ham interested in HF. As I hope you can see in the picture I have a house and a shed
    I should like to have the shack in the shed. There is a light pole on the front of the shed about 15 ft high & I can erect a 10 ft pole on my chimney that will be perhaps 35 feet high. As shown in the picture there is a distance of about 67 ft from one to the other plus a bit more for elevation. I have played around with a hamitup & a random wire & think I can hear some 40m & 20m, so that would probably be the best to focus on.

    The overall layout seems to says "end fed" to me, but as an ignorant newbie, I should be very grateful for any advice
     

    Attached Files:

  2. AJ5J

    AJ5J Ham Member QRZ Page

    You're on the right track and off to a good start. I would suggest either a dipole (fed in the center with balanced line if doable) or an end fed would work for you, especially with the shed being your shack. Check out MyAntennas.com for some well-built EFHWs unless you want to DIY (they require a transformer circuit that is not an everyday garden-variety one).

    Welcome to hamdom and GL with your endeavors. I'm sure many others will chime in shortly, too.

    73, Jeff

    PS: These antennas (and all others) will work best if you can elevate them a bit more---35-45 feet would be great if you can manage such a height---galvanized toprail at Home Depot might work out for you if so.
     
    Last edited: Mar 20, 2016
    WB5YUZ likes this.
  3. WB5YUZ

    WB5YUZ Ham Member QRZ Page

    I'd like second Jeff's advice, especially if you are interested in DX.

    Thirty feet is a respectable height for 20m. It will work ok for 40m. A mast made of 16' 2x4 will get you to 32 or 34 feet pretty easily.

    Dipoles are easily constructed and optimized. This is because the center-fed 1/2 wave dipole presents an impedance which is close to the 50 ohm output of most modern equipment, greatly simplifying things.

    Getting the most out of an end-fed antenna requires quite a bit more understanding about how antennas work, and when you are done, it will have the same radiation pattern as the dipole. Many new hams prefer the end-fed because of its perceived simplicity, but in fact the necessary matching network adds a layer of complexity (and, unless it is done right, objectionable loss).
     
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Since it appears the house is higher than the shed and also has a much larger roof, I'd install a good multiband HF vertical at the peak of the roof using a strong tripod or quadpod -- quadpods are better, stronger and easier to work with -- and run coax over to the shed, probably following whatever path the AC power line takes to get there...couldn't really see that in the pic, maybe it's underground.

    Not only 'would I' do that, but I did do it, here and at several other homes I've owned. There are some very good verticals on the market; the lower cost ones can work very well if you install a good radial system under them. Some are self-contained and do not require the user to add radials, but those models are more expensive.
     
    WB5YUZ likes this.
  5. KD6RF

    KD6RF XML Subscriber QRZ Page

    If you like the "end fed" idea, then you may want to try the good ol' inverted-L.

    It uses a decent set of radials to get good efficiency on the low bands, and produces nice vertically polarized radiation with a low take off angle for good DX work on the low bands.

    On the higher bands, the horizontal section of the L produces nice DX-worthy low take off angle radiation. It's a dB or 3 down from a proper dipole, but still has about 5 or 6 dBi gain on those upper bands.

    A 45 footer, split up in roughly 23 ft tall, 22 ft across, works great fro DX on 80 M through 10 M (6 M as a lobey compromise). If you can go a bit higher, then a 45 x 45 ft inv-L works great from 160M and up to 10 M or 6 M.

    Naturally, it requires a good tuner at the base, or a good BMU (Base Matching Unit) with the tuner located in the shack. The up-side of a tuner is that you aren't stuck in one segment of a band - you get all band, every band operation.

    I use both lengths - I have a 90 ft (45 x 45) and a few 45 ft (23 x 22) inverted-L's scattered around the property.
     
  6. K8JD

    K8JD Ham Member QRZ Page

    What Antenna?
    I would consider the trap vertical antenna made for at least 40-10M. Without trees for supporting dipoles or endfed wires and a desire to work DX, the vertical is the obvious answer. The lower angle radiation from a vertical, compared to a dipole, is ideal for DX. You can have the antenna roof mounted with elevated radials and then only a few for each band, you are interested in, will be enough.
    I have seen some of the older trap vertical designs from Hy-gain or Cushcraft, Newtronics selling for around $ 200.
     
  7. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I fully agree, and 'the house' is a better place for it than the shed.

    The 14AVQ and 5BTV are proven performers that aren't expensive, and the radials can be any kind of wire as long as insulators are used at the ends of the radials. I've used 'speaker wire' for this, and although UV makes the insulation fall off over time, it still works fine.
     
  8. AJ5J

    AJ5J Ham Member QRZ Page

    I was at Lowe's the other day---500' of #14 THHN was about $28 for the solid, $31 for the stranded (or maybe I have that backwards)---anyway either or any other kind of wire would be fine. Insulated is safer as there will be high voltages at the radial ends. Black insulation is much less visible on most roofs if that is of any concern, too.
     

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