Skip to main content

Simple Antennas for the Amateur Radio Operator--a continuing series.

KH6JRM's Amateur Radio Blog

Post #171


Thanks to some good weather today, I was able to get out of the house and work on my modest antenna farm in the backyard.  In my last post, I described a hastily built 20-meter delta loop fed by RG-6 coax.  The loop is working fine and I plan to keep it up for awhile.  Later, I will connect the loop to my station with 450-ohm ladder line, so I can use the antenna for 15 and 10 meters.

After that small antenna project, I was once again on the lookout for other simple antennas that even I could build.  It's true...I'm not the sharpest tool in the shed when it comes to building things, but I do better with each new project.  My fingers have solder burns to prove it!   Anyway, I wanted to improve my emergency indoor antenna without creating problems with RF emissions or TVI.  As I was searching antennas through the internet, I came across an article by Zachary Flemming entitled "How to make an indoor random antenna."  At the time of the article (06 January 2010), Flemming was a PhD candidate at the University of California, Santa Cruz and had apparently devised an antenna that gave him many contacts over the years from his small apartment.

Basically, Flemming ran 50-feet of Radio Shack wire around the ceilings of his apartment and fed the antenna into a RBA 1:1 balun attached to a LDG Z-100 automatic tuner.  He didn't say if a counterpoise was used.  Without a counterpoise, that antenna would "bite" a bit when you used a microphone.  Anyway, assuming he had a decent ground and a working counterpoise, the arrangement proved to be quiet effective in pulling in contacts. 

Here is his list of materials:

50 feet of wire, pushpins to hold up the wire along the ceiling, automatic antenna tuner (LDG Z-100 or equivalent), RBA 1:1 balun, short pieces of RG-8 or RG-58 to connect the transceiver to the antenna and tuner, and a low pass filter to reduce TVI.

Flemming advises those who wish to duplicate his success to run low power (below 100 watts), use digital modes (including cw), and reduce RF exposure and electronic interferrance (TVI) with low pass filters.

As an experiment, I made a similar antenna using 50-feet of wire with one end of some RG-6 coax connected to the wire and the other end of the coax connected to a counterpoise of 50-feet, which snaked along the floor panels and rugs in the qth.  I had an old 1:1 balun in the junk box which I interspaced between the coax and the Drake MN-4 tuner.  I had no RF feedback or "bite" when I used the microphone.  I also had my station ground connected to an 8-foot ground rod outside of the bedroom window.  The indoor antenna worked pretty well, as I received 569 to 579 reports on bands between 40 and 15 meters.  My trusty Yaesu FT-7 with its 10 watt output provide the RF source. 

Perhaps you can use Flemming's original idea for your apartment.  The antenna works given its limitations.  The important thing is getting on the air safely.

Until next time,

Aloha es 73 de KH6JRM--BK29jx15


Popular posts from this blog

G5RV Multi Band HF Dipole Antenna. Post #1555.

If you can't see the video, please insert this title URL into your browser search box: This well-produced and richly illustrated tutorial on the classic G5RV HF Dipole Antenna was presented to the Brandon Amateur Radio Society in Brandon, Florida in 2017 by Bernie Huth (W4BGH).  Bernie does an excellent job of  explaining the pros and cons of this popular HF antenna from the late Louis Varney (G5RV).  Although Varney envisioned his design primarily as a 3/2 wavelength antenna for the 20 meter Amateur Radio band, radio amateurs have used the antenna for multiband use.  The G5RV is an excellent choice for the 20 meter band.  Performance on other HF Amateur Radio bands is good enough to qualify as stand alone HF antenna if you can only erect one HF antenna. For the latest Amateur/Ham Radio news and information, please visit these websites: (a wee

Amateur Radio Bicycle Mobile Setup. Post #1554.

If you can't see the video, please insert this title URL into your browser search box: Here's a way to use Amatuer/Ham Radio while you work on shedding a few pounds in useful exercise.  Why not equip your bicycle for 2 meter/70 cm mobile operation? In this short, well-made video, "taverned" shows us how he used a mag mount antenna, a simple C clamp, and a basic ground system to convert his mountain bike into a mobile station.  The project is straight forward, simple, and gives you emergency communications while you peddle down the road. For the latest Amateur/Ham Radio news and information, please visit these websites: (a weekly podcast which is updated each Friday afternoon). (Amateur Radio News & Information).

An 80-Meter Vertical Helix

Like many amateur radio operators, I live on a small lot surrounded by neighbors, utility lines, and civic-minded citizens concerned about the "attractiveness" of my community.  Whether by design or outright fear, I've adopted the "stealth" approach to ham radio antennas.  It's the old "out of sight, out of mind" idea applied to amateur radio antennas. The amateur radio press is full of articles describing the struggle of amateur radio operators to pursue their hobby under the burdensome regulations of CC & Rs, HOAs, and other civic minded citizens who object to antenna farms.  So far, my modest verticals, loops, and inverted vees have blended well with the vegetation and trees bordering my small backyard.  Vertical antennas have always been a problem because of the limited space for a radial system.  There are times, however, where a shortened vertical for the lower HF bands (such as 80/75 meters) is necessary where horizontal space is lack