Skip to main content

The Amazing Doublet Dipole G5RV--Best Stealth Backyard Antenna

If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=rvBuzQT8zsc.  This is post 2258 in a continuing series of simple ham radio antennas.

Thanks to "Ham Radio CQ" for this exceptionally well-done presentation on a backyard stealth antenna that would be ideal for those home-bound during the annual ARRL Field Day.

Here are some operational and equipment tips from the author.  This list is extensive and should give you enough information to get started on this multi-band HF antenna:




SUBSCRIBED

"https://HamRadioCQ.com for more of MY VIDEOS!!! As an Amazon Associate I earn from qualifying purchases. 👍 G5RV Antenna: https://amzn.to/2FuCmrR 👍 Icom-7300: https://amzn.to/2srAkRD 👍 Jacktite Fiberglass Mast: https://amzn.to/2GZEMhk 👍 TekPower: 13.8V Power https://amzn.to/2SQeF0T 👍 Yaesu 891 https://amzn.to/2RLdPVY 👍 MFJ manual tuner https://amzn.to/2WarftS My favorite ham gear: 👍 Sling Shot 4 tree antenna: https://amzn.to/2SRCDZT 👍 Arborist Throw Box: https://amzn.to/2SSwJr8 👍 Throw Bag2: https://amzn.to/2BVfNt1 👍 Tree Antenna Weight: https://amzn.to/2Fvj6dS 👍 Crazy Antz Backpack: https://amzn.to/2GR7Jz2 👍 Youkits HB1B QRP Rig: https://amzn.to/2D818wn 👍 Portable Speaker: https://amzn.to/2VNK2v4 👍 CW Notes, Space Pen: https://amzn.to/2BQoEvX Solder Station 👍 Work Bench found Here: https://amzn.to/2s5a8Md 👍 Weller Solder Iron: https://amzn.to/2WRmvKn 👍 Printed Circuit Board Holder #1: https://amzn.to/2GfPXVg 👍 Printed Circuit Board Holder #2: https://amzn.to/2TC3Akz My Favorite Camping Gear 👍 Foldup Camp Table: https://amzn.to/2SyziSu 👍 Mr. Buddy Propane Heater: https://amzn.to/2FJk6Lv 👍 Columbia Mens Mosquito Shirt: https://amzn.to/2BQufCC 👍 Hults Bruk Hatchet Axe: https://amzn.to/2AzhZqn Dipole Doublet ~ Best Stealth Small Backyard Antenna for Ham Radio he doublet antenna is a form of dipole that uses a balanced feeder, often open wire feeder and an antenna tuning unit. As open wire feeder is able to operate with levels of standing waves and effectively becomes part of the antenna, it is able to operate over a wide band of frequencies. As a result, the doublet antenna forms a very convenient multiband antenna and it is often used at HF where a number of different HF bands need to be covered, and it is relatively popular with radio amateurs where it enables several bands to be used with a single antenna. Doublet antenna basics The doublet antenna is essentially a balanced system and each half of the top plus each wire in the feed line must be equal in length. The antenna top is not cut to resonate at any particular frequency (unlike the half-wave dipole), and any length may be chosen to suit an individual location. Basic doublet antenna concept Basic concept of a doublet antenna The key to the doublet antenna is the form of feeder used. Open wire or balanced feeders are able to operate as part of the actual antenna itself, not just feeding the power from an unbalanced source. The balanced feeder or open wire feeder is able to operate with standing waves along its length. Note on Balanced Feeder: Balanced feeder can come in one of a variety of forms: open wire, ladder line, or simple ‘ribbon feeder’. It provides the capability for very low loss, provided it does not pass near other objects that might cause imbalanced. Balanced feeder is often used on the HF bands. Read more about Balanced Feeder. Standing waves are a feature of radiating wires, but in the case of the open wire feeder, it consists of two equal length close spaced wires. As these carry equal and opposite currents their radiation cancels. However the feeder still remains part of the overall antenna itself. For a doublet, the top section is typically a minimum of λ / 4 for each section (length L1), i.e. a total length across the top of λ /2. However it is found that the top section, i.e. 2 x L1 can be reduced to about 3 λ / 8 without any major reduction in performance - it has about 98% of the efficiency of a half wave dipole, so the difference will not be noticed. The doublet antenna can operate over a wide range of frequencies and as a result the radiation pattern will change according to its electrical length with respect to the number of wavelengths, or part of that it represents. As the electrical length increases, i.e. as the frequency increases the antenna increases in the number of wavelengths it represents although the physical length remains the same. As the electrical length increases, so the phasing of the fields around the radiating element mean that the radiation changes from a figure of eight pattern for a half wave top radiating element to a pattern that has lobes that increasingly move towards the axis of the doublet antenna."
-----
Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM).


Comments

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: https://www.youtube.com/watch?v=aeNHIQ_j4Dk 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: http://www.HawaiiARRL.info. http://www.arrl.org. http://www.arrl.org/arrl-audio-news (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: https://www.youtube.com/watch?v=2zWb-KnkGdY. 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: http://www.HawaiiARRL.info. http://www.arrl.org. http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon). https://hamradiohawaii.wordpress.com. https://bigislandarrlnews.com. https://amateurradionewsinformation.com (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