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Setup

We just finished an addition on our house, and I have (on the diagonal) ~65 feet of space to work with. The pitch of the roof raises ~5-6 feet from the gutters to the apex of the roof. Roof access is relatively easy, feed line is already run and I have plenty to reach most anywhere I need to go (except the extreme edges and corners, which with a Windom is irrelevant).

What I had

Before the addition, I had a 40-6m Windom up and mounted via ad-hoc "satellite dish mounts", made of PVC, around 2 feet long, and drilled into the fascia of the house. On average, the wire was ~6 inches off the shingles. I was < 2.0 VSWR on all bands the Windom covered.

What I'm looking to accomplish

I'd like to get back at least what I had, if not improve the performance. My biggest issue is the additional raise I'm going to have to deal with.

Question(s)

  1. Has anyone mounted a Windom (or similar wire antenna) on their house in a similar manner to what I'm describing above.

  2. If "Yes" to #1, what did you use to "defeat" the pitch of the roof to get the entire Windom off the shingles?

  3. If "No", any suggestion for what to use to accomplish this? Is longer PVC (perhaps thicker) sufficient?

  4. (General Windom question) Is the wire of the Windom (if attached in a taut manner, using rope attached to insulators at the end of the wires sufficient to support the balun with feed line attached? Or should I consider a "balun mounting" solution and drill into my nice, new roof to help support it. I'm hoping the former will work.

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    $\begingroup$ Is your Windom fed with one or two wires? $\endgroup$
    – Mike Waters
    Aug 20, 2017 at 19:38
  • $\begingroup$ Good question - one. RG-8X, ~60 feet. $\endgroup$
    – CDub
    Aug 20, 2017 at 19:42
  • $\begingroup$ Ok. I should have said conductors instead of "wires". $\endgroup$
    – Mike Waters
    Aug 20, 2017 at 19:44
  • $\begingroup$ I think the answer is still “one” ... sorry, my electrical knowledge has escaped me. $\endgroup$
    – CDub
    Aug 20, 2017 at 19:47
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    $\begingroup$ My fault. A better question would have been fed with 1 wire or coax? (which has two conductors). The reason I asked is that the original Windom was fed with a single wire 14% off-center. What you have is known as an OCF (off-center fed) dipole. That's not important here now. $\endgroup$
    – Mike Waters
    Aug 20, 2017 at 19:55

2 Answers 2

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From your information it seems obvious that raising the antenna is a necessity in order to restore, or improve on, the former situation.

It would be helpful to know the weight of the balun and feedline, but 65 feet (only a few inches off the roof, and therefore not much feedline weight) does not sound too long if the weight of the balun is not ridiculous. I think the most difficult part is making sure the PVC pipes are sufficiently rigid, or at least strong enough to not break when tensioned enough to keep the antenna off the roof. You said the PVC was 2 feet long, but you didn't say the diameter.

I suspect it would be easier to get the antenna higher off the roof if a center support is used. Maybe it could be as simple as 2 small pieces of plywood (maybe 2 feet by 2 feet each?) joined at a 90 degree angle (with a 2x2 at the joint for strength and to make joining easier) placed with the joint up and at a 90 degree angle to the ridge. Matching "v" notches cut in each side of the bottom will make it fit the ridge and give it stability.

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The antenna column in The Spectrum Monitor magazine recently described a loop antenna on a roof shaped very similar to yours. The author just laid the loop directly on the asphalt shingles and fed it with window line. He says it performs very well. Of course this is very subjective and I realize a loop is not the same antenna as your Windom but this experience might serve as one data point that suggests you can avoid the hassle of raising the wire at all.

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  • $\begingroup$ I have mine laying on the roof right now and base VSWR is ~ 6:1 across all bands... The TS-2000 barely is able to tune some of the Extra frequencies. :( $\endgroup$
    – CDub
    Aug 24, 2017 at 2:53

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