Stealth Inverted L mounted on house exterior wall?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by K3CDY, Sep 14, 2020.

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  1. K3CDY

    K3CDY Ham Member QRZ Page

    Like many others, I live in an HOA neighborhood and am researching the best solution for a stealthy HF antenna. I'm fine staying on the higher bands and want something that I can put up and leave up. I'm OK with a remote antenna tuner, and if I can DX, that would be a nice bonus.

    I'm looking at an Inverted L, mounted to the side of my house. The maximum top length is 66', and vertical length is 20' (picture attached).

    * Given attachment to the house, is this a waste of time with the potential interference?
    * Given the maximum dimension limitations, what would be the "ideal" length of each leg to maximize performance?
    * Is a gutter antenna perhaps something to try first (or maybe use as a RX-only antenna)?

    Thanks and 73!

    Gutter Antenna Dimensions.jpg
     
  2. AK5B

    AK5B Ham Member QRZ Page


    What about the vertical part being a taller flagpole? After your neighborhood is used to seeing it (away from your house at least several feet---attach that horizontal wire at the top and going out to something in your back yard. If you use 26-gauge DavisRF Polystealth no one will notice.

    Here's a very thorough and insightful study of inverted Ls by Cebik I ran across yesterday since I am also considering one for my new QTH:

    http://on5au.be/Cebik-2/StraighteningOutTheInverted-l.pdf

    Hope this helps you out. In the meantime, plants lots of trees on your property! :D

    73,

    Jeff
     

    Attached Files:

    Last edited: Sep 14, 2020
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  3. K3CDY

    K3CDY Ham Member QRZ Page

    Interesting idea Jeff. Unfortunately, my back yard is only about 12' deep and my budget is very limited, so I think the flagpole is out.

    The referenced article is excellent! After reading, I'm thinking of a base-fed design, with a total length of around 82' (the max I can run) using the "short vertical leg" approach. I'd place a remote tuner at the feed point, and start measuring & trimming to see what works where. The wildcards for me will be the sloped earth foundation of my house, RF coupling to the metal gutters, and proximity of the wall to the wire.
     
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  4. W1VT

    W1VT Ham Member QRZ Page

    Just try stuff out until you find something that works. A computer optimized antenna is useless if you can't build it.
    Noise is unpredicatable. I had no idea I could easily work DX on an 80M wire vertical hanging from a maple tree with no special receive antennas.
    I had my 80M DXCC in three months! This was in 2012 when were still a lot of DX stations that only QSLed via paper cards.

    I used a short Beverage to work JA8ISU on 80M CW, but I'm not sure that RX antennas are all that helpful these days in working Asia on 80M. He has an unusually good location.
    These days a lot of stations have noise issues and the only time I'm going to work them is when the band peaks and they are loud on the wire vertical.

    Zak W1VT
     
    Last edited: Sep 14, 2020
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  5. K3CDY

    K3CDY Ham Member QRZ Page

    Nice! I certainly expect trial and (a lot of) error, but it's exciting in a geeky way.
     
  6. AK5B

    AK5B Ham Member QRZ Page

    Glad you enjoyed Cebik's article as much as I did. I'm hoping for an 85 or 90-foot 50/50 version if I can get away with it. Flagpoles are not expensive if you build out of telescoping 0.058" wall Alu tubing, either. The great thing is you'd be hiding your antenna in plain site (provided additional wire is 26 gauge "invisible" wire once aloft). If your small backyard isn't enough space, then bend the wire around the corner however you can...


    73,

    Jeff
     
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  7. K3CDY

    K3CDY Ham Member QRZ Page

    Indeed. Definitely something to consider as my finances improve (which are inversely proportional to the COVID outbreak).

    73,

    Bill
     
  8. W1VT

    W1VT Ham Member QRZ Page

    Starting simple will allow you to learn noise and other issues involved in putting your station together.
    If you are lucky you will be able to get enough listening experience to learn about propagation where you live.

    Zak W1VT
     
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  9. K3CDY

    K3CDY Ham Member QRZ Page

    Thanks Zak!

    I'm starting out slowly, especially with all this extra time on my hands. Ironically, it was COVID that prompted me to finally take the plunge into ham radio. I'm on my way to getting my general license, and really looking forward to exploring HF.
     
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  10. KK4OBI

    KK4OBI Ham Member QRZ Page

    Bill,

    Our stories are very similar particularly the part about playing bass and trombone and running a dance band. Anyhow, looking at your house photo my thoughts converged on running an antenna up the back, over the gutter and up to the peak. From there the first choice would be straight on ver the peak and down towards the other gutter. Alternatively turn and run along the ridge line... depends on the antenna length.

    You will find some sort of stand-off to hold the wire away from the roof and metal gutter makes a substantial difference in tuning and getting out. If you have shingles take a look at Amerimax "Hidden Hook" MO722B.

    For the antenna consider an End-Fed type for 40-20-14-10 meters. Put the transformer end near the ground at the back of the house. Ground it there. Run coax to your operating position with a choke mounted around 10 feet from the transformer and before the coax enters the house.

    With luck the antenna should usable without a tuner. Otherwise a radio with a built-in tuner will should suffice. If you try adjusting the antenna length, be cautious. Any change on one band changes all bands. Fold the end back rather than cutting.
     
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