2009-01-13
Antenna and Weather Station Work
A recent wind storm broke the support rope for my end-fed 40 metre dipole (also used as a random wire at times). While putting it back up I took the opportunity to do some other antenna work and put up the weather station my parents gave me in July last year!
For many years I've had a commercial discone antenna I picked up at the Wyong field day in a DSE clearance sale. IIRC it cost me about $40 which is *much* less than it normally retailed for. I've had it assembled on the balcony for several years, continuously getting in the way and spending most of its time upside-down collecting water in the mounting tube. Putting it up was long overdue. No idea what I will actually use it for, perhaps the airband - scanning was never really a big hobby for me.
Not exactly the ideal place for it, right next to my HF base-loaded vertical, but for now this is way better than sitting upside down. I chickened out on using the right-angle bargeboard mount in the manner it was intended after some back of the envelope calculations suggested the couple it would produce with an estimated wind loading from our infamous "southerly busters" was approaching the estimated mechanical limits of the bargeboard! Instead the bargeboard mount was used as a simple mast to attach the antenna to the balcony railing. At some point in the future I'll clean up this install and probably use a small bargeboard mount in that corner for other antennas.
I'm now out of coax lines to the balcony again, I only had sufficient coax to install three in the last coax run, it is now time to go and purchase some more and fill the remaining BNC feed-thru. I'll need another pair of wallplates to install more after this, and I doubt I can get away with too many more antennas on the balcony anyway. Eventually the HF vertical will have an remote tuning mechanism to cover HF and release one coax run currently used for 30 metres instead of just swapping the same run between 80 and 30 metres.
The 2 metre "flower-pot" vertical has been lashed to the railing in a very temporary manner for almost exactly a year now, it was also well due for relocation to a more permanent spot. I placed it on a large bargeboard mount with an offset. This raised it several metres improving reception of most repeaters. Unfortunately its RG-213 coax run is still partially water logged and must be replaced eventually.
The bargeboard mount also now hosts the weather station anemometer and wind vane assembly. While not an ideal position for such a device, this is the best I can do given the limited mounting options.
The weather station's tipping bucket rain gauge was mounted to the balcony railing, again not ideal but fairly unshadowed. The temperature/pressure/humidity and RF backhaul link module was mounted under the eaves in the exposed corner of the balcony to keep it out of direct sunlight but still offer good airflow (and distance it from the air conditioning condenser/compresser unit).
The 30 metre loaded inverted-V dipole remains in place, but unconnected. It should really be removed and replaced by something more efficient and actually useful, perhaps a 20 metre antenna for PSK31, but I hope eventually to run all HF through the vertical with remote tuning leaving more space for experimental antennas.
The work cost me a fairly high UV radiation dose to the upper forearms, enough to cause erythema but (so far at least) no pain or desquamation. I was wearing a hat and sunglasses, but no topical protectant. I suspect the majority of the dose was absorbed on the walk to and from the hardware store to collect the coach screws used to install the bargeboard mounting bracket, not during the actual work on the balcony. I got a *far* larger dose on the DX-pedition with Peter last year. The exposure is very minor compared to what I see many people on the beach take on a daily basis - salmon pink and pealing but still going out for more - they will no doubt regret those burns in time.
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