Weather-proofing your antennas


#1

Alright, let’s see some pictures and ideas on simple and effective ways to weather-proof your antennas.


#2

Mounting the thing in the attic, if it works, can help. But these things work best when in free air with a good view.

A benefit of the frequency – the bottoms of 2 liter soda bottles for ground planes. Cover the thing and leave the bottom open, or cut strips to tape to the feedline.

Co-linears, use clear shrink tubing with the top folded over – even if you then put it in pvc. The heat shrink keeps all those joints from moving around as much.

important – seal the connector and feedline at the base of the antenna! You don’t want water infiltrating the connectors or the feedline! (I used 9913, which is well known for imitating a garden hose, then switched to LMR cables).

Hams use self-vulcanizing tape, like Weatherseal, then wrapped with Scotch 88 electrical tape. The self-vulcanizing stuff keeps out moisture and is a form-fitting seal. But it isn’t very UV resistant, so cover that with Scotch 88 electrical tape so it will last many seasons. I mention Scotch 88 as it holds up; a lot of the hardware store cheepie tapes do not.

Know what a drip loop in a feedline is? You should.

A guarantee: antennas and feedlines very rarely fail in good weather. Trust me on this.

bob k6rtm


#3

I put the top of a water bottle over a cantenna to keep water from pooling in the cup at the top (actually, the bottom of the drink can).


#4

and this also protects the feedline connection to the antenna…


#5

I have no plans to mount in the attic. Although I have a 2 storey house, I also have a mast for my weather station where I plan to attach an antenna. Elevation is slightly higher than my position from about NE to SE, so increased elevation would help. My current mast is set so that the top is 40’ above ground level. Mast is made from a swimming pool skimmer handle that can extend to 16’. Rooftop is at 28’, so it’s only partly extended. I’ll probably mount on PVC to elevate above the mast, to avoid radio interference from the mast’s aluminum.

The two liter bottle idea is a good one. I get slightly better performance with a metal lamp shade resting over the spokes of the typical ground plane, but I may try without first.

I figure I should probably get a powered USB extender and mount the Raspberry Pi in a separate housing under the roof peak but not in the attic. It is on the north side of the house and would be significantly cooler than in the attic.

Currently, I have it mounted as high as it will go in the NW corner of my 2nd storey bedroom, essentially clipped to the ceiling.


#6

I’ve got 3 masts on the roof of our house; the discone at one end, and this one in the middle:

It’s got the Davis weather station, with the pointy thing in the middle being the GPS antenna I use for timing and frequency reference. The nice thing about this setup is that the anemometer is directly to the North – where we don’t have any GPS satellites going, so it doesn’t obstruct the “view.”

In the background you can see the multi-band HF vertical that’s mounted atop the garage.

bob


#7

I’ve got a wireless Davis station. Unfortunately, even with the wireless version you can’t separate the rain collector from the solar and UV collectors. That seems absurd to me. The proper location for the rain collector is ground level. The best place for the solar sensors is as high as possible. Interestingly, the anemometer has a separate sending unit so can be separated. That’s what’s on the mast I referenced before. Do you feed to wunderground? If so, what’s your station ID? Mine’s KTXAUSTI48.