Wednesday, October 29, 2014

Simple Ham Radio Antennas: How to make a cheap and easy 4:1 balun. Post #317.


Most of my HF antennas are fed with 450 ohm ladder line going into a 4:1 balun and then continuing on to my Drake MN-4 antenna transmatch with  a short length of RG-8 coaxial cable. Although I have an excellent 4:1 balun in the shack (a W9INN 4:1 balun), I felt the need to have a spare just in case my primary balun fails to work. This article by the Wiltshire Man fills that need. I spent a leisurely hour or so in the shack assembling this simple device. I'm not a mechanical genius, so I just took my time watching the video and putting the unit together. Once I finished this project, I tested it with my 80 meter inverted vee. I was running slightly below 50 watts output from my Ten-Tec Argosy II transceiver and experienced no overheating in the balun, which was connected between the 450 ohm ladder line and the Drake transmatch. The balun worked without any problems on 80, 40, 20, 15, and 10 meters. Following the test, I removed the homebrewed balun and put it in my "go kit" for portable operations. I'll use this balun as a backup to my W9INN 4:1 balun. This was an enjoyable project. 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).

Saturday, October 25, 2014

Simple Ham Radio Antennas: Dipole and Inverted V Basics. Post #316.


Sometimes, simple is best. In the case of amateur radio antennas, an easily constructed dipole or inverted v antenna will get you on the air quickly at minimal cost. Dave Turlock's video is a basic, well-explained tutorial on how dipoles and inverted v antennas work. Dave covers construction techniques, mounting of the antenna, and tuning of this simple, yet effective antenna. For monoband use, use a good grade of 50 ohm coaxial cable for your feedline. If you wish multi-band capability, use 300 ohm TV twin lead or 450 ohm ladder line for the feedline. This type of feeder must be used with a balanced antenna tuner or fed into a 4:1 balun and then connected to your antenna transmatch ("tuner") with a short piece of 50 ohm coaxial cable. Either way, your new dipole should be mounted as high as you can without endangering your safety. My last inverted v was designed for 40 through 10 meters by cutting the radiating segments to my lowest preferred frequency (7.088 MHz), feeding it with 450 0hm ladder line, and then connecting the feedline to a W9INN 4:1 balun, which, in turn, was connected to my Drake MN-4 antenna transmatch with 12 feet/ 3.65 meters of RG-8X with UHF connectors. I was fortunate to find a Norfolk Pine Tree branch about 40 feet/12.19 meters above ground level to support the inverted v. I used a slingshot from Wal-Mart to launch the antenna into the branches. So far, this simple inverted v has done well for both local and DX contacts. Besides, there's something nice about making your own wire antenna with locally available resources. For the latest in Amateur Radio news and events, please refer to the blog sidebars. These news feeds are updated daily. Thanks for joining us today! Aloha es 73 de Russ (KH6JRM).

Wednesday, October 22, 2014

Simple Ham Radio Antennas: Delta Loop Antenna 40 through 10 meters. Post #315


I found this fascinating article by SV1CDY while I was searching for some multi-band loop antennas. I've used full-wave loops in the past and found them to be easy to build, portable, and cheap. I duplicated SV1CDY's design without resorting to the 56.7 uH coil, since I had enough space in my backyard for a full wavelength loop cut for 40 meters (7.088 MHz). Like SV1CDY, I used some #18 AWG speaker wire for the feedline and connected that line to a W9INN 4:1 balun and then, using a short piece of RG-8X coaxial cable with UHF connectors, I attached that assembly to my Drake MN-4 antenna transmatch. For my version of SV1CDY's short loop, I used #12 AWG house wiring for the loop, three ceramic insulators to support the loop, a 33-foot/10.06 meters MFJ telescoping fiberglass mast, some prepositioned wooden stakes and nylon rope to tie off the bottom of the delta loop, and a 6-foot/1.82 meters wooden stake to keep the feedline off the ground until it reached the 4:1 balun attached to my garage wall. Using the general formula 1005/f (MHz)=L (ft) and a design frequency of 7.088 MHz, I cut three equal pieces of wire measuring 47.26 feet (47 feet, 3.12 inches)/14.40 meters. The delta loop was fed at the lower left hand corner with two-conductor #18 AWG speaker wire from Radio Shack. With the Drake MN-4 in the system, I was able to get a SWR of 1:1 on 40, 20, 15, and 10 meters using my trusty Ten-Tech Argosy II transceiver. I had plenty of contacts on 20 and 15 meters during the day, with some excellent Pacific and mainland U.S. contacts on 40 meters after sunset. This is a great antenna for both home and portable use. And yes, you get to listen to an outstanding jazz track by McCoy Tyner ("Just In Time") while you build this simple, effective antenna. For more details, visit http://sv1cdy.blogspot.gr/2011/10/short-delta-loop-antenna-for-40-to-6.html. For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated daily. Aloha es 73 de Russ (KH6JRM).

Friday, October 17, 2014

Simple Ham Radio Antennas: A portable HF vertical antenna for 20 meters. Post #314.


.If you need an emergency or portable antenna for 20 meters, then this video by Dave (W0ZF) will get you on the air quickly and inexpensively. The only materials I had to buy were some nylon rope and a telescoping fiberglass fishing pole from the Hilo "Sports Authority" outlet. The pole cost me $30.00. I followed Dave's instructions and soon had a light weight portable antenna that performed well in a local beach park I used for testing. The vertical element should be a quarter wavelength for the 20 meter frequency of your choice. I chose 14.200 MHz and cut my vertical element and my radial wires to a length of 16.47 feet (16 feet, 5.6 inches)/5.02 meters. My coaxial feedline was 50 feet/15.24 meters of RG-8X coaxial cable with UHF connectors. I used a spare Budwig Hi-Que center coax connector to attach the antenna elements, with the + side connected to the vertical element and the - side connected to the ground radial system. My antenna wire and radials were some left over Radio Shack #18 AWG speaker wire. My radial system consisted of 12 quarter wave wires cut for 14.200 MHz. Performance of the antenna was quite good using a battery powered Ten-Tec Argosy II transceiver. I brought along my Drake MN-4 transmatch to take care of any SWR issues I ran into. Without the Drake MN-4 in the antenna system, my SWR measured 1.6 to 1 at my chosen frequency. The transmatch brought that down to 1:1 across the entire 20 meter band. I was pleasantly surprised how well this quickly made vertical antenna worked, considering the low power I was using (10 watts). So, if you need a cheap, efficient vertical antenna for 20 meters, try Dave's design. It works. For the latest Amateur Radio news and events, please check out the news feeds in the blog sidebars. These feeds are updated daily. Until next time, Aloha es 73 de Russ (KH6JRM).

Monday, October 13, 2014

Simple Ham Radio Antennas: The 10 minute dipole. Post #313


This is what I call a "quick and dirty" dipole antenna suitable for field expedient use or for portable operation. This video by Ten-Tec's Scott Robbins (W4PA) has received a bit of criticism, but its basic premise is excellent: "Cut, solder, and tie off." Since I'm a bit slow in the soldering department (far sightedness doesn't help much in close work...I had to use my bifocals on this project), I just took my time and built Scott's basic model in about a half-hour. I cut the antenna for the mid-point of the 40 meter band (7.150 MHz) and used some extra RG-8X coax as the feedline. Fortunately, I had two well-placed Norfolk Pine Trees on my property and was able to get the dipole about 40 ft/12.19 meters above ground. I made a choke balun out of the last few feet of the coax nearest the antenna elements to keep stay rf off the coax shield. Without my trusty Drake MN-4 transmatch in the line, I got an initial SWR of 1.6:1. The "tuner" brought that down to 1:1 without much trouble. This antenna is not meant for permanent installation and it's a bit of a compromise, but, this easily assembled antenna will get you on the air with a decent signal. In an emergency, that may be all that's necessary to get a message to the outside world. Overall, this video does a pretty good job of making a basic, no frills dipole antenna. For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated daily.Aloha es 73 de Russ (KH6JRM).

Thursday, October 9, 2014

Simple Ham Radio Antennas: Building a multi-band HF Dipole Antenna. Post #312.


Do you want an efficient multi-band HF antenna that occupies a small space and requires the minimum of construction and maintenance? Then, this video from Larry, the "Radio Ham Guy" is for you. Most of the materials will be found in your ham shack, garage storage room, or at the nearest home improvement or hardware store. This version of the popular "fan dipole" requires only one 50 ohm coaxial cable feed line, a center coax connector, a few end insulators, a tall support and a few tie off points above ground to work. Using the familiar dipole formula (468/f(MHz)=L(ft), you cut separate dipoles for each band of use, connect them to a common center connector, and "fan out" the various elements to nearby support masts, trees, or any other tall object. With careful trimming (beginning with the lowest frequency band of your choice), you can probably get a low SWR for each amateur radio band you chose. I always use an antenna transmatch (i.e. "tuner") as part of the antenna system, just to get the best match possible. It is possible to use the 40 meter dipole on 15 meters if you cut the 40 meter segments to the lower portion of the band. This will make the antenna work as a third harmonic in the phone portion of the 15 meter band. When in doubt, just make a separate 15 meter dipole, attach it to the common center connector, and "fan out" the dipole elements like the other dipoles. This antenna doesn't require a ground plane and will give you years of good service. To reduce the chance of stray rf getting into your shack, you can insert a 1:1 balun just below the dipole center connector. Or, you can "roll your own" rf choke out of a few feet of your feed line. Larry's video is clear, concise, and well-presented. Antenna building is one of the few pursuits amateur radio operators can do that doesn't require a lot of cash or time. Wire antennas can work just as well as commercial products. 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 e-mail subscription or by tapping into the blog RSS feed.Aloha es 73 de Russ (KH6JRM).

Tuesday, October 7, 2014

Simple Ham Radio Antennas: A Ham Radio 10 meter ground plane antenna. Post #311.


Another great video tutorial from antenna guru Dave Tadlock. This time, Dave designs, builds, and uses a simple ground plane antenna for 10 meters. Although Dave says his design can be ground mounted, a true ground plane antenna is always elevated to decouple the radials from the actual ground to eliminate ground losses. Dave's instructions are clear, precise, and often humorous. I've built several ground plane antennas following Dave's lead. The hardest of the lot was for 40 meters. In order to get the radial system off the ground, I had to use a slingshot and a length of weighted nylon rope to shoot the vertical element to a branch about 40 ft/12.19 meters above ground. With the bottom of the vertical element at 7 ft/2.13 meters above ground, it was easy to attach four, sloping quarter wave radials to the coax connector and tie them off at pre-positioned stakes. It's a lot easier to build a 10 meter ground plane. If you chose a frequency of 28.400 MHz (in the Tecnician Class SSB segment of the band), the vertical element and its corresponding system of 4 sloping radials (about 45-degrees) would each measure 8.23 ft/2.51 meters. By placing this arrangement on a 20 ft/6.28 meter pvc mast, you would get the base of the antenna almost 3/8 wavelength above ground. This antenna provides excellent DX possibilities when propagation is favorable. Even on "bad" propagation days, this antenna will provide many local and regional contacts. Building antennas is fun and educational. Dave does a good job of explaining how this type of antenna works. 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. Until next time, Aloha es 73 de Russ (KH6JRM).

Saturday, October 4, 2014

Getting started on Ham Radio 2M FM, Part 3. Post #310.


This is part 3 of Randy's (K7AGE) tutorial on using a 2 meter handheld transceiver (ICOM IC-V80 Sport HT). In this segment, Randy explains how frequency, offset, and tone are programmed into your HT so that you can enjoy the many features of local FM repeaters. Randy also describes how to program memory channels into the popular ICOM IC-V80 Sport HT and how to recall them. The video is well-done, clear, and easy to follow. For the latest Amateur Radio News and Events, please check out the blog sidebars. These news feeds are updated daily. Thanks for joining us today! You can follow our blog community with a free email subscription or by tapping into the blog RSS feed. Until next time, Aloha es 73 de Russ (KH6JRM).

Friday, October 3, 2014

Getting started on Ham Radio 2M FM, Part 2. Post #309.


Here's part 2 of Randy's (K7AGE) series on getting started on Ham Radio 2 meter FM. In this easy to follow video, Randy shows you how to program the popular ICOM IC-V80 Sport HT, how to get on the air quickly, and to how to use the basics of FM operating to your best advantage. Randy's videos can be used as basic a basic 2 meter tutorial for newly-licensed hams or to refresh the memories of some of us old timers who don't use 2 meters as often as we should. Overall, Randy has done a good job of covering the essential operating protocols for the 2 meter Amateur Radio band. 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. Until next time,Aloha de Russ (KH6JRM).

Wednesday, October 1, 2014

Getting started on Ham Radio 2M FM, Part 1. Post #308


Are you a newly licensed amateur radio operator and want to get on 2 meter FM with a minimum of hassle and problems? Then, this well-produced video by K7AGE is for you! Even though I've been an amateur radio operator since 1977, I always learn something new about the hobby by consulting hams who've been in the hobby for many years. K7AGE is an excellent "elmer" (mentor) and takes you step by step into the world of 2 meter FM using the popular Icom IC-V80 Sport VHF hand held transceiver. This is part 1 of a three-part study of 2 meter FM. For the latest Amateur Radio News and Events, please check out the blog sidebars. These news feeds are updated daily. Aloha es 73 de Russ (KH6JRM).