One more antenna

This year I put up another antenna in the attic, an end-fed 10/20/40-meter Horizon tri-band from down under (Bushcomm).

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It’s just over 50 feet in length and just fits the attic running east-west down the centerline of the house. The 50-foot coax feedline acts as a counterpoise, then runs through an isolator in the attic and down a wall into the shack.

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The antenna’s bandwidth is a little tight at 40m, but good at the frequencies I need for Winlink HF packet (SWR under 1:1.4 around 7.1 MHz), and reasonably flat at 20m (under 1:2) and 10m (under 1:1.5):

Today I made contacts on 40 and 20 meters to two different Winlink stations.

So now I have a total of four working antennas under one roof, including two X50s for VHF / UHF and one 70cm yagi for digital ATV. They all come down through one wall to my office on the main floor.

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On top is a two-radio go box with an Icom 880H and a Yaesu 857D; below it is the portable D-ATV repeater which can also be used as a TV transceiver (note the video camera set up on top for input).

BARCFest 2016

I demonstrated the digital quad box for BARCFest attendees and attracted lots of interest. I had two TV backpack transmitters of my own placed in corners of the building, plus a signal from Jim KH6HTV showing home video, plus a video input from a stationary drone camera belonging to Allen KØARK (the receiver is the white device on the far left of the table; it is connected directly into the HDMI switch).

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On the right I have a laptop receiving the video stream over an Ethernet network, using a Monarch HD streaming appliance (the silver part in the middle of the quad box).

The embedded HDMI switch makes it easy to substitute video sources into the quad processor as well as choose which images are shown on monitors or fed into the streaming device.

My birthday present

I managed to convince my homeowner’s association to allow me put an antenna on the roof, so I assembled it today (which just happens to be my birthday). I also have one on the third-floor balcony. Maybe I can call it a work of modern art!

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Since the rooftop is flat, and I don’t want the future expense of a damaged roof, I used a Rohn FRM166 non-penetrating mount.

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With the concrete blocks as ballast, the mount (like the X-50 antenna) should be good for winds up to 130 mph — faster than what’s been recorded in or around Boulder.

The antenna is about 30 feet up on a townhouse which sits at about 5630 feet above sea level. Unfortunately, given the hills behind my house, my HAAT turned out to be negative. The antenna does have a great view north, east, and south, though.