Category Archives: Antennas

Celestron NexStar hamlib driver for Satellite Tracking

From Eric Grumling WE7U

This is a demonstration of the Celestron NexStar hamlib driver. A few years ago I put in a feature request to the Hamlib project asking if they would develop a rotctl driver for a telescope mount. This week I found out that it had been put out for testing and Stephane, F8CFE had been trying to reach me to have me try it. I’m happy to report that it seems to be working quite well. Unfortunately the weather has not been cooperative so I had to test indoors. I made this video to get the word out so maybe others can test out this easy, inexpensive way to add some automation to their shack.

Build the hamlib driver using the source code here: http://sourceforge.net/p/hamlib/featu… (scroll down about 1/2 way down the page for links and instructions). Will work with any telescope mount that supports NexStar protocol.

HB9CV Antenna and Calculator

From Jeff, (VE3COJ)

P1030522-Web

P1030524-Web

 

HB9CV Antenna & calculator… Jeff’s demo for presentation Thursday, September 10, 2015, at the BARC general meeting. For more details on this antenna, please see the following links.

http://www.changpuak.ch/electronics/HB9CV.php

http://barc.ca/wordpress/wp-content/uploads/bsk-pdf-manager/108_A-DIRECTIONAL-ANTENNA.PDF

 

Antenna Restrictions and Making Antennas Fit

Where there is a will, there is a way.

Nancy lives in a community for people aged 55 and older. The home-owner’s association banned her from putting up any kind of antenna. John Amodeo, producer of the hit TV show “Last Man Standing” (starring Tim Allen, himself a ham radio operator) and I traveled to Florida to see what we could do to make a 39 ft long antenna, fit in a 23 ft long attic!

Amateur Radio lightweight Satellite Tracker

From (name and callsign unknown)

This is the start of my learning process to construct a lightweight cost effective antenna PTZ rotor setup. Currently my learning consists of a mini Arduino board, some large RC servos and Ham Radio Deluxe.

Other related info,

The perfect controller to this project is the K3NG Arduino based Controller. http://blog.radioartisan.com/yaesu-rotator-computer-serial-interface/
Here, the full list of the features: https://github.com/k3ng/k3ng_rotator_controller/wiki/110-Features  73 de Pu4vlt

Quadrifilar Helical Antennas

From Chuck (VE3IUO)

I got this from my friend Bob Cutter, KI0G Colorado / SPI, Texas. He is mounting his on his boat trailer.

With the declining HF conditions and the launch of some new satellites I decided to build a UHF/VHF omnidirectional system.

IMG_8416

 

The photos are the UHF unit and the 2M will fit under it.

IMG_8420

It is #6 copper and I found these splice blocks that make connection of the coax and loops fairly easy. Here is the construction article I used:

http://uuki.kapsi.fi/qha.html

RF Ground Explained

Here is a video explaining RF ground,  by Michael Martens (KB9VBR).

Today we talk about the RF ground, what it is and when it’s necessary. The purpose of the RF ground is to act as a reflector. It doesn’t radiate RF energy, but instead interacts with the antenna’s radiating elements by mirroring and reflecting that energy, creating a predictable RF radiation pattern. So the RF ground is important, right. Then why doesn’t every antenna require one? Well they do, but just not in a way that might seem obvious. Continue watching for more. . .