DIY Ham Equipment
Are you interested in building your own Amateur Radio equipment?  Whether you are a beginning builder,
a homebrew veteran or anywhere in between, the LARC Technology Committee has a building project for you. The Committee members (Mike, KBØQH; Tyler, KDØBSA; and Bill, W1LXE) have selected three Club building projects, described below.  And Joe, KØNEB, has agreed to provide expert guidance on the construction of each project for those who would like to improve their construction skills. The exact dates for the construction projects will be determined once we find out the level of interest in each project.

Project 1: Hendricks Deluxe Tenna Dipper Kit

This project will give you a test instrument capable of determining the 50-ohm resonant frequency of an HF antenna.
The small size and battery operation make this unit ideal for use in the field as well as in your shack. Although this unit won’t provide all of the information generated by full-size antenna analyzers, it will give you the resonant frequency of your antenna on a four-digit display, and it will indicate a 50-ohm match when its SWR LED indicator goes out.  The Tenna Dipper covers 3 to 30 MHz and, when used with an antenna tuner (ATU), will allow quick and virtually QRM-free matching of transceiver and antenna impedance. The approximate cost of this Dipper kit is $75.00.

Project 2: End-Fed 6-40 Meter Multi-band HF Antenna Matchbox.

This project will give you an inexpensive, multiband, end-fed HF antenna matchbox that is quick and easy to set up and use.  The end-fed feature adds convenience, but it does present another issue.  The problem with an end-fed halfwave antenna is that the antenna presents a high impedance, creating a significant mismatch with the usual transceiver impedance of 50 ohms. This mismatch is significantly greater than typical tuners can accommodate without a matching transformer.  So this project creates a trifilar wound 9:1 UNUN (unbalance to unbalance)
toroid matching transformer that will match the high input impedance of an end-fed antenna into the range where
most antenna tuners can produce good performance. The matchbox handles 100 watts of power. This project requires an antenna tuner to achieve satisfactory SWR. You could either build the matchbox alone or add antenna wire and insulators to have a complete antenna package. The approximate cost of this matchbox kit is $25.00-$30.00.

Project 3: A Neat Dual-Band Antenna.

This project will give you an easy-to-build and inexpensive VHF / UHF antenna for field or base station use. Described
in the August 2006 QST (Page 50), and demonstrated by Mike, KBØDNP, at a recent LARC meeting, this antenna
can be built using inexpensive materials from a hardware store or even materials you may already own.  The primary components are 3/4 inch aluminum tubing and some PVC pipe. The approximate cost of this antenna kit with
all required parts is $25.00-$30.00.

If you are interested in one or more of these projects, please sign up at the May 9 Club meeting or let one of the Committee members know in person or by e-mail: Mike mewalshter@gmail. com>, Tyler <kdobsa@yahoo.com>or Bill <w1lxe@arrl.net>. We plan to finalize the numbers after the May Club meeting.