Monday, September 29, 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 Drake MN-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 panel. Another 6 ft/1.82 meters piece of RG-8X with UHF connectors ran to the Drake MN-4. Shorter lengths of coax interconnected the Ten-Tec Argosy II, low-pass filter, and dummy load to the Drake MN-4 ATU. The "longwire" antenna was tied to a 100 ft/30.48 meters length of nylon cord with a fishing sinker attached and shot over a tree branch approximately 50 ft/15.24 meters above ground. Once I tied off the antenna to a nearby tree stump and adjusted the antenna for tension, I was ready to operate. With the use of 450 ohm ladder line, a 4:1 balun, and a good ATU, I was able to work many mainland U.S. and Pacific stations using less than 50 watts output. The Drake MN-4 kept SWR below 1.5 to 1 on all amateur bands between 80 and 10 meters. This is an excellent antenna for portable or home use. Just be sure to use a counterpoise system and a good antenna ATU with this antenna. For the latest Amateur Radio News and Events, please check out the blog sidebar. These news feeds are updated daily. You can also get more Amateur Radio news and upcoming events by visiting my amateur radio news site--http://kh6jrm.com. Thanks for being with us today!Aloha es 73 de Russ (KH6JRM).

Sunday, September 28, 2014

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 found the project fun and educational. David's video provides some helpful tips and guidance. Aloha es 73 de Russ.

Thursday, September 25, 2014

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 the neighbors (out of sight, out of mind). Using the new formula and cutting each element for my chosen frequency of 7.088 MHz (the frequency of the Hawaii Afternoon net), I cut two pieces of #12 AWG house wire to a length of 82.53 ft/25.16 meters each. These wires would comprise each half of the inverted vee. A ground radial system is not required with this antenna. Rather than use 50 ohm coaxial cable for the feed line, I opted to use 75 ft/22.86 meters of 450 ohm ladder line as the feed line. Using a balanced feed line in conjunction with a W9INN 4:1 balun and my Drake MN-4 antenna transmatch (tuner), I could get multiband use between 40 and 10 meters with just one antenna. I built this antenna on the ground. I had a spare 33 ft/10.06 meters MFJ telescoping fiberglass mast which would support the feed line and the two antenna elements. I used a "ladder lock" device to attach the antenna elements to each leg of the ladder line. All connections were soldered and covered with several layers of vinyl electrical tape. Once the mast was raised on a wooden support stake and the drooping elements tied off at prepositioned 10 ft/3.04 meters pvc pipes, I ran the 450 ohm ladder line to the 4:1 balun attached to the garage wall. A 6 ft/1.82 meters length of RG-8X coax went from the balun to the window patch panel and from there, another 6 ft/1.82 meters of RG-8X coax went to the Drake MN-4. Shorter pieces of coax joined the Argosy II transceiver, dummy load, and low-pass filter to the Drake MN-4 antenna transmatch. Performance on 40, 20, 15, and 10 meters was good when propagation was "in". Using Stan's overall guidance, I found design and construction of this basic  antenna  simple and inexpensive. Most of the materials I had in the shack. What I didn't have, I bought at Home Depot and Ace Hardware. The antenna is a bit large, but the performance of this antenna more than compensates for its size. ----------------------------------------------------------- For the latest Amateur Radio News and events, please check out the blog sidebars. These news feeds are updated daily. Until next time, Aloha es 73 de Russ (KH6JRM).

Monday, September 22, 2014

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 paracord guy ropes, a dual-band 2 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.

Sunday, September 21, 2014

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).

Thursday, September 18, 2014

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 Radio News and Events, please check out the blog sidebars. These news feeds are updated daily. Until next time, Aloha de Russ (KH6JRM).

Wednesday, September 17, 2014

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).

Monday, September 15, 2014

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 and explains the basic steps thoroughly. For the latest amateur radio news and events, check out the blog sidebars. These news feeds are update 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 de Russ (KH6JRM).

Saturday, September 13, 2014

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).

Friday, September 12, 2014

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).

Thursday, September 11, 2014

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 RSS feed. Until next time, Russ Roberts (KH6JRM).

Wednesday, September 10, 2014

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).

Thursday, September 4, 2014

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 a chosen frequency of 3.500 MHz, each leg of the dipole measures out to be 66.8-ft/20.38 meters.  You may want to cut the antenna a bit longer to allow for trimming and SWR adjustments.

Materials available:

Sixty-six-feet/20.12 meters of 450 ohm ladder line.

Three egg-shaped ceramic insulators.  One insulator would serve as the center connection point between the ladder line and the two dipole segments.  The remaining two insulators would be attached to the free end of each antenna segment.

Two dipole segments, each measuring 66.8-ft/20.38 meters. I used some #14 AWG wire I stored in the garage for the antenna elements.


Two, 100-ft/30.48 meters of nylon rope and two fishing sinkers (2 oz.)  The rope would be attached to the end insulator of each element and would be launched over tree limbs by a slingshot.

One, homemade slingshot.

One W9INN 4:1 balun.  The 450 ohm ladder line would be attached to the balun.

Two, 6-ft/1.82 meters lengths of RG-8X with UHF connectors.  One piece of coax would lead from the 4:1 balun to the window patch panel; the other would go from the patch panel to the "antenna tuner."

One MFJ 941 E Versa Tuner II.

One Ten-Tec Argosy II, J-38 CW key, and microphone.

One Heathkit Dummy Load.

One B&W low pass filter.

Assorted tools.

One "counterpoise bundle", consisting of one 1/4 wavelength wire (leftover #22 AWG) for each band of operation (80, 40, 30, 20, 15, and 10 meters).

Assembly:

The Open-Wire Dipole (Doublet) was built on the ground.  

The 450 ohm feedline was threaded through the center insulator and soldered to each leg of the dipole.  Each connection was wrapped with several layers of vinyl electrical tape.

Nylon rope (100-ft/30.48 meters) was attached to each end insulator and tied off to a fishing sinker.

I launched each antenna segment (with the rope and sinker attached) over a high tree limb with a slingshot.  The chosen branches were 40-ft/12.19 meters above ground level.  The trees were approximately 135-ft/41.5 meters apart, so the antenna fit was a bit tight.

Each segment was loosely tied off to a tree stump, while adjustments were made to give the dipole a uniform horizontal appearance.  Once I was satisfied with the nearly horizontal position of the dipole, I tightened the launching ropes around smaller trees, leaving some slack in the antenna to compensate for the wind.

I ran the 450 ohm ladder line to the W9INN 4:1 balun attached to the garage wall (approximately 8-ft/2.43 meters above ground level.  The ladder line passed within 8 inches/20.32 cm of the metal garage roof. This distance didn't affect the feed line too much, since I had no trouble adjusting the MFJ 941 E Versa Tuner II for a low SWR.

A 6-ft (1.82 meters) length of RG-8X with UHF connectors went from the 4:1 balun to the window patch panel.  Another 6-ft (1.82 meters) piece of RG-8X went from the patch panel to the MFJ 941 E Versa Tuner II.  Short pieces of RG-8X connected the tuner to the Ten-Tec Argosy II, the Heathkit Dummy Load, and the B&W low pass filter.  As a last step, I connected the "counterpoise bundle" to the ground lug of the antenna tuner.

Initial Results:

I was able to get a 1:1 SWR on all 80, 40, 30, 20 ,15, and 10 meter amateur radio frequencies with the aid of the MFJ 941 E Versa Tuner II.  I also got a 1:1 SWR using the old Drake MN-4 antenna tuner (excepting 30 meters--the old MN-4 didn't cover 30 meters).

Using a maximum power of 25 watts, I was able to maintain good CW and SSB contacts on the U.S. mainland and throughout the Pacific Ocean.  The best daytime contacts were on 20 and 15 meters, while 40 and 80 meters did well around sunset through the early morning hours.  Ten meters was quite noisy and no contacts were made.

This was a fun and inexpensive antenna to make.  Fortunately, I was able to salvage most of the wire from the antennas lost during the hurricane.  Try to get your dipole as high as you can.  My height of approximately 40-ft/12.19 meters was a little on the short side for 80 and 40 meter DX, but I did get a few DX contacts on those bands.  Performance on 20 and 15 meters was pretty good.

This simple antenna is easy to build and will deliver plenty of contacts, both local and DX.  By using a balanced feed line, you can use this antenna on several amateur radio bands....more bang for the buck!

Resources:

http://youtu.be.com/watch?v=wMP45MVFpY (simple introduction to the theory of "open-wire dipoles" by Stan Gribilisco (W1CV).

http://www.sgcworld.com?Publications/Downloads/ClassicMultiband.pdf.

http://www.arrl.org/files/file/Technology/tis/info/pdf/0683033pdf.

http://www.w4neq.com/htm/doublet.htm.

http://g3ynh.info/atu/sgc230.html.

Be sure to check out the blog sidebars for the latest in amateur radio news and activities.  These news feeds are updated daily.

I'm also running a selection of amateur radio related youtube videos on the sidebar. Some of these videos are quite fascinating.

You can follow our blog community with a free email subscription or by tapping into the blog RSS feed.

Until next time,

73 de Russ (KH6JRM).

Tuesday, September 2, 2014

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

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

Comment: Russ Roberts (KH6JRM).

Summary:

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 multiband antenna.

2.  Two wires are needed to power a lamp.  The same is true of your antenna. The best antenna configuration calls for feeding energy from the transmitter to a balanced antenna, such as a dipole. If you can do this with a balanced, parallel-wire feed line, so much the better.

3.  Antenna "gain" is derived by shaping and aiming RF where you want it to go. For example, the so-called "beam antenna" gets its name from the fact that it concentrates RF energy in a particular direction, like a flashlight.

4.  The function of an antenna tuner is to effect a match between the output of a transmitter and the input of an antenna system.  Antenna tuners are variable-impedance transformers that allow you to transform the antenna system impedance (which can be almost anything) to the 50 ohm input of the transmitter.

5. A wire antenna doesn't always have to be center fed.  For example, you can feed a long wire at the end with a two-wire feed line.  Connect one conductor of the feed line, but not the other.  This type of antenna used to be called an end-fed Zepp.  To work well, however, the ground side of the antenna tuner needs to be connected to a network or radial wires, or a counterpoise system.  Another "oldie but goodie" is an off-center fed dipole, called a Windom.  Cut a wire a half wavelength long, find the center, and connect a single wire 14% off center.  This also requires a counterpoise for good results.  The impedance is about 600 ohms, so you'll definitely need an antenna tuner.

6.  A dipole antenna does not have to be perfectly horizontal.  The antenna can be on an incline, or even vertical.  The shape of the antenna and its height above ground will affect its impedance at the feed point, so you may need to experiment to obtain a low SWR, if you are feeding the antenna with coaxial cable.

7.  Vertical antennas shorter than half wavelength need a ground system.  This usually takes the form of radial wires, either elevated or buried.  

8.  With vertical antennas, there is no such thing as too many radials.  The more radials you install, the more efficient your antenna becomes.  Yes, you can reach a point where the benefits of adding more radials levels off, but that number is somewhere around 100!

9.  Having a 1:1 SWR does not mean you have a good antenna.  A 1:1 reading says nothing about how well your antenna is working.  For example, a vertical antenna with a poor ground system can be tuned to the point where you'll measure a 1:1 SWR at your station, but the antenna is so inefficient, most of the RF is being wasted as heat!

10.  Always use the best feed line you can afford.  Resist the urge to be penny wise and pound foolish.  This is particularly true of coax.  Better (less lossy) coax will cost more, but this is the cable that is carrying your precious RF signal to and from your antenna.  A good investment now will pay off in better antenna system performance.
-------------------------------30---------------------------

So, there you have ten additional tips to make your antenna more efficient.  Combined with James Duffy's "Rules of Thumb for Beginners", you will have the necessary facts to build and use an efficient, cost effective wire antenna that will give you hours of enjoyment.  Building wire antennas with materials found around your shack or from the nearest hardware  store or home improvement outlet is one of the most enjoyable parts of amateur radio.  Have fun.

Resources:

Ford, Steve (WB8IMY). "The Classic Multiband Dipole Antenna."  "QST", March 2004.

Duffy, James R. (KK6MC/5).  "Antennas:  Some Rules of Thumb for Beginners." http://www.norcalqrp.com/features/bgnsant.html. Dated 31 January 2004.

Field, Van (W2OQL).  "HF Antennas 101".  "QST", September 2004.

Be sure to check the blog sidebar for the latest news from the world of Amateur Radio.  These newsfeeds are updated daily.

You can follow our blog community with a free email subscription or by tapping into the blog RSS feed.

Until next time,

Russ Roberts (KH6JRM).
Laupahoehoe, Hawaii (BK29jx15).