Showing posts from September, 2014

Simple Ham Radio Antennas: M0VST's 50 meter longwire antenna set up. Post #307.

This short video by M0VST covers most of the basics involved in making an effective longwire antenna, covering the amateur radio bands between 160 to 10 meters. I've built several of these "longwire" antennas and have found that an ATU (antenna tuner) and a good counterpoise system really help to produce a quality signal. Unlike M0VST's "longwire antenna", my version was cut to a length of 67-ft/20.42 meters, enough to cover amateur radio bands between 80 and 10 meters. My counterpoise system was a compromise arrangement consisting of four, quarter wave radial wires for each band of use (80, 40, 20, 15, and 10 meters). I also attached a "quarter wave radial bundle" to the ground lug of my trusty DrakeMN-4 ATU. I used approximately 60 ft/18.29 meters of 450 ohm ladder line as the antenna feed line. The ladder line was attached to a W9INN 4:1 balun. A 6-ft/1.82 meters length of RG-8X with UHF connectors ran from the balun to the window patch…

Simple Ham Radio Antennas: A $4.00 Ham Radio Satellite Antenna. Post #305..

I admit it. I tend to procrastinate too much these days, always delaying a simple project because something else gets in the way. But not today. I've been looking for a simple, inexpensive hand-held 2 meter/70 cm yagi satellite antenna for working the SO-50 and other FM radio satellites. With the number of microsats, Cubesats, and edu-sats in orbit these days, there is no excuse for not building your own antenna for these "birds". Most modern handhelds can be used to contact these satellites with a decent antenna. So, following some of the advice given by Dave Tadlock in this video, I decided to collect the necessary materials for this ultra simple antenna. Fortunately, I had most of the materials at the QTH and was lucky enough to have a neighborhood True Value store not far from my home. The antenna works quite well when I can time the passes correctly. At times, my arm gets a bit tired, but that issue can be solved with a camera tripod or some other device. I…

Simple Ham Radio Antennas: The Extended Double Zepp Antenna. Post #304

This historical amateur radio antenna is becoming a bit more popular these days because it delivers modest gain over a horizontal dipole (about 3 dB) and is simple to build. This video by Stan Gibilisco covers all of the basics of this antenna and its construction. While it is perhaps best to use two supporting masts for the antenna, it can work reasonably well configured as an inverted vee. According to Stan, the EDZ antenna is basically "a collinear array of two 5/8 waves in phase." So, each antenna element will be a bit longer than the dipole most of us are accustomed to building. Also, the usual dipole formula, 468/f(MHz), doesn't apply here. After consulting several texts and antenna books, I chose to use the formula 585/f(MHz) for my EDZ Antenna. My last EDZ was cut for 20 meters and it worked very well. This time around, my property is a bit larger and I thought a 40 meter EDZ configured as an inverted vee would fit within my property without being seen by …

Simple Ham Radio Antennas: A Portable 2 meter/70 cm Ham Radio Antenna. Post #303

KF7ETX has built an easily assembled portable VHF/UHF antenna system that can be set up most anywhere, from your home to an emergency station in the country. All it requires a painter's pole support mast, three paracordguy ropes, a dual-band2 meter/70 meter antenna, and some low-loss coaxial cable. I have a similar arrangement at my QTH, where I use a homebrewed 5/8 wavelength 2 meter antenna supported by a 33-ft/10.06 MFJ telescoping fiberglass mast. The mast is secured by clamps on the side of my garage. I feed the antenna with 50-ft/15.24 meters of RG-213 coaxial cable. The mast can also be broken down for portable use. The antenna works very well from my rural location. The antenna used in this video by KF7ETX can be made from locally available materials from the nearest hardware or home improvement outlet. This is a simple, effective antenna that will give you hours of fun at your favorite park, beach, or mountain top. Have fun. Aloha es 73 de KH6JRM.

Simple Ham Radio Antennas: Stealth Amateur Radio Antenna System (7 MHz to 1.3 GHz) AKA HDTV antenna. Post #302.

Here's a curious design for a stealth antenna from Jim Whitaker. The antenna appears to be a type of Off Center Fed Dipole (OFCD) capable of working on 40, 20, 15, 10, 6 meters. The antenna functions as a discone for 6 meters, 2 meters, and 70 cm. I've built a few OFCD antennas, but they didn't look like Jim's. You may want to test Jim's idea if your antenna space is limited or discouraged by HOAs and CC&Rs.For the latest Amateur Radio News and Events, please check the blog sidebars. These news feeds are updated daily. Aloha es 73 de Russ (KH6JRM).

Maximize 2 Meter HT or Dual Band Radio Performance With This Easy Tip. Post #301.

Are you dissatisfied with the performance of your HT? Perhaps the cause of your concern is the "rubber duckie" antenna supplied with your radio. Larry Shaunce (WD0AKX) shows how adding a simple counterpoise wire to the base of your HT's antenna can supply the missing half of a dipole antenna. This simple addition can add just enough "push" to hit that distant repeater without resorting to higher power or an amplifier. I tried Larry's idea on my old Kenwood Th-21A FM transceiver. I kept the old "rubber duckie" antenna and added a 19-inch/48.26 cm length of #22 AWG hookup wire as a counterpoise. With this cheap, easily made modification, I was able to hit all of the 2 meter repeaters in the Hilo, Hawaii area with full quieting. This antenna is sometimes called a "Tiger Tail". You can find variations of this antenna on several web sites. Larry's explanation is excellent and down-to-earth. Great video. For the latest Amateur…

Ham Radio Tutorial - HF Radio Wave Propogation. Post #300.

Tyler, N7TFP, exlplains how radio waves travel around the world via "skip" or skywave propagation. An informative and useful video. This video would be good to show to people studying for their first amateur radio license. Good job! For the latest Amateur Radio News and Events, please check out the blog sidebars. These news feeds are updated daily. You can follow our blog community with a free email subscription or by tapping into the blog RSS feed. Thanks for joining us today! Until next time, Aloha es 73 de Russ (KH6JRM).

Simple Ham Radio Antennas: a basic 20 meter portable antenna. Post #299.

Shortly after the passage of Tropical Storm Iselle (07-08 August 2014) through Hawaii Island, I rebuilt part of my damaged antenna farm with a simple, cheap, and portable 20 meter vertical antenna that could be used at home or in a portable or emergency situation. I adapted the design presented by W0ZF by making it suitable for a permanent operation at the QTH. I used a 33-ft/10.06 meter MFJ telescoping fiberglass mast secured to the edge of my garage. The center pin of my RG-8X feedline was attached to the vertical element, while the coax braid was attached to the garage's 30-ft/9.14 meters by 16-ft/4.87 meters metal roof using a stainless steel nut/bolt and a battery clip. The roof connection was coated with a caulking compound and varnish to protect the attachment point from the weather. The antenna works very well on 20 meters. My old Drake MN-4 antenna transmatch (tuner) can make this antenna work on 15, 17, 12, and 10 meters with a low SWR. The video is well-done an…

ARRL National Centennial Convention 2014 - FEMA Administrator Craig Fuga...

This is post #298. Fugate spoke before some 800 guests at the Friday evening ARRL Centennial Convention banquet in Hartford, Connecticut. Earlier that day, he and ARRL President Kay Craigie (N3KN), signed a memorandum of Agreement (MOA) aimed at enhancing cooperation between the ARRL and FEMA in the area of disaster communication. In his remarks at the banquet, Fugate said that before he even became FEMA administrator, it became clear to him that Amateur Radio could support ad hoc and innovative communication without relying on conventional telecommunications systems. In his remarks, Fugate noted that "The more sophisticated our systems become, the more fragile they become...the relevancy of ham radio only grows...Amateur Radio is taking that hobby and turning it into saving lives." Earlier, Fugate upgraded to the General Class Amateur Radio License. After Fugate's talk, President Craigie presented him with the ARRL Medal of Honor. Aloha de Russ (KH6JRM).

Directional Antennas (Yagi Antennas). Post #297

Excellent, concise, and well-produced video about yagi antennas from Diana Eng (KC2UHB). The use of a flashlight to explain how beams work is quite effective. This video could be used in an introductory Amateur Radio course. Nice job! Aloha de Russ (KH6JRM).

Coat Hanger HDTV Antenna! Post #296

I was looking for a quick and easy HDTV antenna for my new home in the Orchidland Estates area of the Puna District when I came across this video from Ross Voorhees. Rather than spend $40-$60 for a commercial version, I decided to use Ross's idea and build my HDTV antenna. Although my xyl and I don't watch much television these days, we do enjoy a few PBS specials and the evening news. Ross's antenna design is cheap and easy to build. There are more sophisticated designs available, but, for now, Ross's antenna does the job. This is a great construction project. I found most of the components around the garage or in my "radio room." Most neighborhood hardware stores can supply you with what you need. Good luck and have fun! For the latest Amateur Radio news and events, please check out the news feeds in the blog sidebars. These feeds are updated daily. You can follow our blog community with a free email subscription or by tapping into the blog …

Yaesu FT-450D Walkthrough. Post #295.

The Yaesu FT-450D is a popular HF transceiver that has proven its success since its introduction in 2011. I've used this rig on ARRL Field Days and in portable operations with my ham friends. The rig is simple to use and performs well, even in high interference conditions. This would make an ideal introductory rig for a new licensee or a dependable transceiver for the more experienced ham. Nice rig. Aloha de Russ (KH6JRM).

Simple Ham Radio Antennas. The Delta Loop. Post #294.

Simple Ham Radio Antennas. The Open-Wire Dipole (Doublet). Post #293

I'm still in the process of restoring my "antenna farm" after the passing of Tropical Storm Iselle on 07-08 August 2014.  I lost a few trees on my Orchidland Estates property, most of which were supporting several HF wire antennas.  I salvaged most of the wire and the 450 ohm feedline from the storm.  While I cleaned up the mess, I erected a simple multiband vertical antenna using a tall Norfolk Pine Tree as an antenna support.

Next on the list is the restoration of my approximately 134-ft/40.85 meters  center-fed horizontal dipole.  The antenna is fed with 450 ohm ladder line which goes into a W9INN 4:1 balun and then via a short length of RG-8X coax into a MFJ 941E Versa Tuner II.  This feed arrangement allows multiband coverage from 3.500 MHz through 29.000 MHz.

Although the antenna requires two tall supports (trees or masts), construction of the antenna is simple and the dipole doesn't require a ground radial system.

Using the general formula, 468/f(MHz)=L(feet) and…

Simple Ham Radio Antennas: Antenna Basics, part II. Post #292

Source:  Field, Van (W2OQI). "HF Antennas 101." "QST", September 2004.

Comment: Russ Roberts (KH6JRM).


This article is a follow-up to my last post, where I quoted James R. Duffey (KK6MC/5) from his article entitled "Antennas--Some Rules of Thumb for Beginners."  These two articles will give new licensees as well as us "old timers" a gentle reminder of some basic truths concerning antenna design and theory. Thanks to Dean Manley (KH6B) for running off a copy of this helpful article.  Like the previous essay from James R. Duffy, I will place this in my antenna reference library.  

Article excerpts:

Here are 10 tips and truisms that every ham should know:

1.  An antenna does not have to be resonant to work. The only reason to make an antenna resonant is to eliminate the need for a impedance-matching device such as an "antenna tuner."  Actually, a non-resonant wire dipole antenna fed with open-wire line and an antenna tuner is a great m…