Posted: 3/20/2014 5:10:22 PM EDT
|
I whipped out the credit card last week and ordered a new antenna (Arrow GP-146/440) along with coax to run it into the house. I had grand plans to remove the Dish antenna we don't use and clamp the antenna to its mast. Turns out Dish masts are 1-5/8" OD, and Arrow antennas have a max clamp size of 1-1/2". DERP.
Stopped at Home Despot this morning and picked up a few needfuls to finish the install: - a 1-1/4" flexible coupler (1-1/4x1 would have been preferable, but none were to be found at HD) - a 1x36" black iron nipple - a bag of zip ties This afternoon I climbed my ass back up on the roof, and checked fit. The coupler is a darn-near perfect fit for the Dish mast, requiring only a few turns on the pipe clamp to be solid. I wrapped a dozen turns of duct tape around the base of the iron pipe and slipped that into the mast, then tightened down the coupler as much as possible. There is a little play but it's in no danger of coming out. With that done, I slipped the antenna clamp over the top and cranked it down... then looked at orientation and realized I'd put KC directly in the shadow of the iron pipe. It might not matter, but then again, it might - so I loosened the clamp up and spun the antenna around 90 degrees to put the 70cm stub facing roughly north, hopefully giving me good coverage of the metro area repeaters. (Yes, I can slide the antenna up a few inches to the very end of the mast, and may need to - but I'll test this first.) I tossed the coil of coax over the side and started zip-tying things together... and together ... and together ... I put in a pair of drip loops at the bottom, tucked it through the top corner of the garage door, and made it in to the basement... then ran out of time and had to get ready for work. But the antenna? That's up. I should be done on the roof for the foreseeable future. I did consider a longer piece of pipe, but this was heavy enough and got the ground radials well clear of the roof. When I'm no longer renting, I'll look at a true mast. 
Stay tuned in the next few days for a micro EmComm box construction... |
|
Quoted:
Lightning ground? Looks good and I like the idea of re-using the existing dish mount. No lighting ground yet. There's a little ground wire on the dish mast, but I'd not trust that to take a strike. I suspect it was to ground whatever static the wind might have generated on the Dish. And I'm still learning ... is a lightning ground really necessary on this sort of antenna? If so, what gauge wire? Suggestions for a good lightning ground, given that I rent and can't drive a rod? 
|
| i have the same antenna up in about the same config. there are trees and houses nearby that are taller. i can get into repeaters pretty far away with ease and use all the local repeaters on low power no problem. not a bad antenna for the money and will become my field portable when a high gain takes it place eventually. |