At the August 2013 meeting of the Conejo Valley Amateur Radio Club, a panel discussion was held on portable antennas.

Transcription

1 Introduction to Portable Antennas At the August 2013 meeting of the Conejo Valley Amateur Radio Club, a panel discussion was held on portable antennas. A poll was taken at the beginning of the discussion indicating that 40-50% of those present (about 40 people) lived in planned unit developments with CCR's that, at best, forced them to be stealth operators or, at worst, become portable operators. This is not an uncommon situation as more and more people live in housing covered by CCR's. Our discussion was limited to HF operation. While there is certainly a big audience for portable VHF and higher frequency operation, that would be a topic for another discussion. We engaged a relatively new comer to HF operation and he provided a very interesting list of questions, some of which stumped our panel. Each of our panel members presented and discussed their favorite portable antenna. The antennas ranged from home brewed dipoles weighing a few ounces to mast-mounted beams weighing pounds mounted on masts. Some could be easily erected by one person, others would need two. These antennas cost anywhere from a few dollars to $600. Some fit, along with a QRP CW transceiver in a shoe box. The largest would need a good sized car trunk. The presentation materials, including links to sources of information, are contained in this file. CVARC hopes you find them useful.

2 What makes an antenna portable? Boy, everybody will have an opinion on this question. Perhaps the way to think about what makes an antenna portable depends on the answer to some questions: What do you plan to use to transport it and how much space/ weight is available? How many people are available to help with the installation/tear down (alternatively is there equipment to do the heavy lifting?) What are the conditions where you plan to use the antenna. The less transportation space and weight available the fewer the number of antennas that are portable. No one is going to back pack an antenna that weighs more than a few pounds. Who could resist bringing an easy to assemble beam if they had car trunk space or a pickup truck to move it and provide a base to support the mast? If you are the only one who is going to erect or tear down the antenna, the size and weight of the antenna will be limited by your own physical abilities. However, if you have some supplemental handling and lifting equipment or maybe a tilt up antenna, larger antennas can be considered portable. If you are going to operate in an area with lots of tall trees or existing supports the best portable might be a dipole or other suspended wire antenna. If you are going to be out in the open you need to supply the supports, you can still use a wire antenna, of course, but why not consider a beam or higher performance mast supported antenna if you have to bring supports anyway. For Purposes of Discussion, we used the following definition: A portable antenna is one that can be erected by one or two people in less than 90 minutes and torn down in a similar amount of time, leaving a nice chunk of the day for operating. It would be intended to be used in a remote location and for purposes of this discussion would not be permanently attached to a vehicle or trailer. What do you think?

3 Questions to Chris Sasso: 1. What do you want to do with a portable antenna? I am just getting started with Hf radio, and I am not sure what my favorite bands are yet. In fact I think I am having a bit of trouble because I only seem to pick up local hams on 40 meters. I am currently using a 50 foot piece of wire, but hope to get a dipole with a 1:1 balun on the roof of my townhouse this week. I am at a stand-still because if all the bands seem to be dead, except 40M, and I am stuck on what length to make the dipole, that will multiband. I do have a tuner. I am open to suggestions for other types of antennas. I have an HOA, so I have to keep my antenna low-profile, low-cost in case of someone tampering or removing it, and I don t expect that a tower will be permitted. 2. How much do you expect to spend on it? I suppose I would be willing to spend $ or less. If someone really twisted my arm, perhaps more.

4 3. Where do you plan to use it? Generally (no pun intended) I would be using it at my townhouse. I do not know if the HOA is going to raise a stink about my dipole, so if they do, an easy up easy down, antenna, that I can erect at night, and takedown when I finish hamming for the evening. I have not yet considered back packing, camping or mobile Hf. YET 4. Do you expect to erect it yourself or with help? I would definitely need something I could set up by myself. I dream of a tiny toggle switch, that with a flick of my finger, a 50 foot tower would gracefully ascend from my rooftop like a magic bean stock, and like a bouquet of flowers, several antennas would unfold themselves. 5. Do you intend to back pack with it, carry it in a trunk, or the back of a truck? Sure! But I am not there yet.

5 6. Do you want single or multiple bands (which ones)? Multiband until I find a favorite band. What is yours? 7. Do you expect to use it on a mast? Not really, unless it can disappear during the day. I have a challenging situation with the HOA, but once I am comfortably on-the-air, and know more, I think my creativity may flow. I have not successfully QSLed yet

6 Chris' Questions for the Club: Some Initial Answers: 1. How do I get started getting on the air? 2. How important is ground rod? 3. How do I deal with neighbors that might pick up interference? 4. How do I know how much power to use, or how far my signal is going? ARRL has a terrific book on stealthy antennas that will likely answer most of your questions. Small Antennas for Small Spaces is the title. You might want to consider going truly portable with an inverted V dipole on a telescoping mast that is supported by a wheel of your car. If you build the dipole yourself, buy a telescoping mast and wheel support and some miscellaneous cord you might make your budget. If it is cut for 80 m your tuner will likely give you other bands. You will have to find an accommodating operating location, but it will get you outdoors. You could also build an off-center fed dipole. Eric Peterson and I used one for the field day digital station that tuned up nicely on multiple bands. The balun for this antenna might push your budget over $200, but it makes for a better inverted V.

7 More Questions for Club Discussion: As someone new to Hf, it is hard to know which 5 questions to ask, so many questions string together. I suppose the main questions I have are these. 1. How do I determine proper antenna polarization? And why? 2. Do the ground plain legs of an antenna radiate Rf? a. Question based on the signal strength pattern of a dipole. b. Also would play a factor on antenna s location; driven element priority, counterpoise could just hang limp. 3. Can I zigzag a dipole? a. What would happen to the signal strength pattern and resonance? 4. Explain harmonics, and how to achieve resonance on multiple bands. a. Shunts, traps, multiple radiators in series or parallel. 5. How does a directional antenna function? a. Beam antennas; the lengths & spacing of directors.

8 Buddipole

9 Buddipole Deluxe Package $ The Buddipole Deluxe Package includes everything you need for setting up an efficient portable antenna solution anywhere in the world in just a few minutes. The package includes the following custom components which all fit into the padded cordura nylon custom-carrying bag: Videos The Buddipole Antenna (9 bands, 2-40 meters) with 25 foot coax assembly (includes VersaTee) Tripod - extendable legs and locking base Portable Mast extends to 8 in height Rotating Arm Kit change configurations Antenna System Bag padded cordura nylon w/shoulder strap Extra Telescopic Whip 3 extra Coil Clips Length collapsed: 24 inches (60cm) Length extended (antenna): 16 feet (4.9m) Power Rating: QRP to 250 Watts Weight: 9.5 lbs (4,3 KG) Coil Diameter: 1.75 inches (4.5cm) Frequency Coverage: 7 to 54MHz continuous, plus 144 to 148MHz

10 Brad Ormsby W6VO What's good about it - gain, directionality, easy to put up, light weight, many bands in kit What's bad about it - expensive, adjustments for changing bands, best to have an antenna tuner Where you got it - Buddipole or Elecraft Would you recommend it to another starting ham? Yes Would you recommend it to any ham? Yes Where have you used it? Home, Park, Beach, Mountains How far did it go? US so far but is capable of DX How much did it cost? $199 Buddipole -$399 for the deluxe Buddipole How long to erect? About 15 minutes Does it need a mast? Yes How many people to erect it? One URL for more information. Whatever else you want to mention about it. Great for portable operation and experimenting with different antenna configurations in areas without trees or other structures for connecting long wires.

11 The Goold Ol' 40m Dipole How simple can you get?! RG-174 Junk box center insulator #24 cu coated steel The first antenna for many hams, but it never grows old! Packed Size Depending on wire size, can be as small as your fist. Erected Size 66' long, 10-20' high. Weight a few ounces. Advantages Easy to build Very lightweight for backpacking, etc. Bagged separately to keep from tangling the wires. Bagged separately to avoid tangles Disadvantages Single band (although 15m works on 3 rd harmonic) Parts List Wire 68' of #14 - #24 gauge copper (or copper coated steel) stranded recommended. Insulators 2 egg style or just some plastic rings Rope for ends and center Center insulator Coax (RG174 for short runs and low power, RG58 for over 30') + connector(s). How to build it 1. Cut wire to length two lengths each 33' long. The basic equation is: length = 468 / Freq The length is in feet, frequency in MHz. Note that we've added a bit for tuning. Add a bit more if insulated wire, shrink some if using as an inverted-v.

12 2. Attach one end of each wire to the center insulator leaving a bit of extra. Solder coax or connector to this extra length. 3. Attach other end to the insulators. 4. Attach ropes to the insulators, other end to tie-off points. 5. Attach coax to connector (unless you soldered it). 6. Raise the center to 20-30' elevation. 7. Pull ropes to gently tension the wires. 8. Use SWR bridge or antenna analyzer to optimize length reduce legs simultaneously. Recommended For... The perfect first antenna, virtually any ham can build this! As with any antenna, see the Handbook for hints. Where Used Home Backpacking Farthest Contacts South America, Japan, various U.S. Cost Homebuilt: Wire - $10 (Home Depot, or The WireMan) Rope - $5 (Harbor Freight) Coax - $15 (HRO) Insulators - $0 (Scrap box) Purchased (but they're so easy to build...): HRO or AES for about $60 How long to erect? How many people needed? 1 person in about 15 minutes (not including mast) Mast? Useful, otherwise, can use a rope over a tree-branch in the field. More Information at ARRL Antenna Book ARRL Wire Antennas All over the web, see for a calculator. Your's truly... WB6PYK <wb6pyk@arrl.net>

13 End Fed Dipole Antennas An end fed, vertical or sloping dipole using a coaxial cable for the lower half, the center conductor for the upper half, a choke in the middle and a matching box at the feed point. ENDFEDZ Specifications MODEL BAND 1.5: VSWR LENGTH POWER HANDLING EF-80 80M 130kHz@1:5 or less W EF-60 60M 225kHz@ W EF-40 40M 225kHz@ W EF-30 30M 1.5 : W EF-20H 20M 300kHz W EF-20 20M 300kHz W EF-17H 17M 350kHz W EF-17 17M 350kHz W EF-15H 15M 400kHz W EF-15 15M 400kHz W EF-12H 12M 500kHz W EF-12 12M 500kHz W EF-10H 10M 600kHz W EF-10 10M 600kHz W EF-6 6M 1.2MHz W Multi-Band QRP EF-10/20/40MKII 10M/20M/40M 500/300/100kHz@ W EFT-10/20/40 Trail Friendly 10M/20M/40M 500/300/100kHz@ W 40M: 140 khz@2:1 EF-40/30 40M/30M 54 25W 30M: 500 khz@1.5:1 Multi-Band 100W 40M: 150 khz@2:1 EF-40/20 40M/20M W 20M: 500 khz@1.5:1 General Component Information o o o o Pricing $ CUSTOM #18 STRANDED COPPER CLAD SILVER TEFLON SO-239 BLACK POLYETHYLENE STAINLESS STEEL

14 What's good about it - very light weight (back packable), many bands available (some multiband), Relatively low cost, stealthy What's bad about it - one band at a time, need to hang in tree, relatively delicate, long length, Narrow Bandwidth Would recommend it to any ham interested in back packing or stealth operation Where have you used it? Various back packing trips How much did it cost? $52-75 for each band, $125 for multi-band How long to erect? Depends on how good you are at getting it over a tree branch, but could be 5-10 minutes. Does it need a mast? Not necessarily How many people to erect it? one URL for more information.

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17 Folding Antenna ~$600 Depending on Options Kit 5-Band Folding Beam (20/17/15/12/10m) This kit contains everything required to build the antenna. The center post, inner conductor and the 1" fiberglass joiner are completely machined. The feedpoint and cord support is molded onto the center post. The spreaders have molded swivel joint halves and tips. To finish the antenna the following things need to be done: - center post: mount socket connector and inner feed conductor - assemble hub and put on inner spreader sections, join with center post - complete spreaders with remaining sections - mount wire clips onto spreaders - cut all wires and cords to length - build driver-spacer-reflector assemblies - make loops on support cords and hang onto antenna - mount wire elements to spreaders and connect to center post - final tuning Shipping Time ~ 6 weeks, Assembly time is approx. 6-8 hours. You need to do all this only once You will also need a portable mast and guy ropes, Coax Cable, and common mode choke

18 Length collapsed: 50 inches Diameter collapsed: 8 inches Diameter extended (antenna): 23 feet Power Rating: Full Legal Limit Weight: 13 lbs Bill Willcox KF6JQO KF6JQO@yahoo.com What's good about it - gain, directionality, broadband, all 6 bands available simultaneously, light weight, many bands in kit, corrosion resistant (plastic and Aluminum) What's bad about it - very expensive, best to have two people to erect and tear down Source and more information - Foldingantennas.com Probably would only recommend it to an experienced ham who wants multi-band, light-weight beam Where have you used it? Santa Rosa Valley How far did it go? Michigan and Japan How much did it cost? $585 for 6 bands, choke, spares and other goodies How long to erect? Eric and I think it might be done in 15 minutes, but the first time to assemble and tune took 16 hours Does it need a mast? Yes How many people to erect it? two URL for more information.

19 HAMSTICK DIPOLE

20 HAMSTICK DIPOLE ~$60-75 for a single band, additional bands $40-$50 (80/40/20/17/15/12/10m) This is a do it yourself project that might be better termed a poor man's buddy pole. It consists of two Hamsticks (no longer in production but available on Ebay and there are other manufacturers) and a dipole mount. It can be mounted horizontally or vertically and can be either mounted on a pole or hung in tree. Google Hamstick Dipole for a huge amount of additional information. You will also need a portable mast and guy ropes, or a convenient tree and rope, Coax Cable, and common mode choke

21 Length collapsed: 48 inches Diameter collapsed: 2-4 inches Length extended (antenna): 16 feet Power Rating: watts Weight: 5 lbs Bill Willcox KF6JQO KF6JQO@yahoo.com What's good about it - simple, relatively cheap, all bands except 160M available, light weight, well suited to NVIS What's bad about it - narrow band, time consuming to change bands, not very robust, limited range Source and more information - Google: hamstick antennas Would be great for a new ham With caveats and mindful of limitations would recommend it to any ham. Where have you used it? Simi Valley How far did it go? Western US How much did it cost? $120 for 4 bands, plus choke, mast and Coax How long to erect? 10 minutes Does it need a mast? Not Necessarily How many people to erect it? one

22 HF backpack system using an AS-1887A / PRC-74 Antenna

23 This website has more info about the antenna:

24 This is a grainy video showing construction in the first half. The last half shows a pedestrian walking around with the antenna in a back pack. HFPack puts it all together:

25 CONNECT TO COAX CONDUCTOR CONNECT TO COAX SHIELD CRAPPIE FISHING POLE JAY HARLAND AG6JF - 8 AUG 2013 OAK PLUG 20 FT CRAPPIE FISHING POLE 20 METER ANTENNA ~17 FT LONG (1/4 λ) REAL BIG NAIL ~45 ~60 40 METER ANTENNA ~34 FT LONG (1/4 λ) CONSTRUTION STRING. ADJUST TO KEEP TENTION ON ANTENNAS GROUND LINE METER PORTABLE INVERTED - "V" ANTENNA

26 The Off-Center-Fed Dipole (OCFD) A great, simple, portable multi-band antenna A great antenna for home or in the field, multi-band, simple to build, erect and tune. And it works! Balun Packed Size Easily fits in a shoebox. Even smaller with appropriate design and construction. Erected Size 135' long, minimum 20' high. Weight about 1 lb. Advantages Easy to build Multi-band (80, 40, 20, 17, 10, 6m) Can be relatively lightweight for backpacking, etc. Disadvantages Requires 4:1 Balun (but easily built or bought) No 15m band (with this configuration) Narrower bandwidth per-band than a dipole Parts List Wire 140' of #14 - #18 gauge copper (or copper coated steel) stranded recommended. Insulators 2 egg style Rope for ends and center 4:1 Current Balun see the CVARC web site for the Hugh Bosma Balun, or there are various available at HRO or on the Internet. Coax (RG58 for short runs, RG8X for over 50', especially at 6m). How to build it 1. Cut wire to length one 92' long, the other 46' long. (We've added a bit for tuning.)

27 2. Attach one end of each wire to the legs of the balun. Solder for good connection. 3. Attach other end to the insulators 4. Attach ropes to the insulators 5. Attach coax to balun. 6. Raise the balun to 30-40' elevation if at all possible, performance drops below about 20-25'. 7. Pull ropes to gently tension the wires. 8. Use SWR bridge or antenna analyzer to optimize length reduce legs simultaneously. Recommended For... Most any ham with basic electrical/electronic skills or just as a CVARC member to help! As with any antenna, see the Handbook for hints. The hardest part is probably step 8 but even that shouldn't take more than minutes. Where Used Field Day 2013 Home Farthest Contacts Guam, Argentina, New Zealand all with QRP (5 watts or less) Cost Homebuilt: Wire - $15 (Home Depot) Rope - $5 (Harbor Freight) Coax - $25 (HRO) Balun - $25 (GigaParts) Purchased (several places, including): How long to erect? How many people needed? 1 person in about 15 minutes (not including mast) Mast? Useful, otherwise, can use a rope over a tree-branch in the field. More Information at ARRL Antenna Book ARRL Wire Antennas All over the web, there's a Yahoo group <windom_antenna> also. Your's truly... WB6PYK <wb6pyk@arrl.net>

28 Outbacker Joey Antenna Description and Price Courtesy of Eham Reviews: 1 Average rating: 4.0/5 MSRP: $$299 Description: The Outbacker Joey antenna is designed to be used in conjunction with low power portable transceivers (20 Watts PEP Max). On most transceivers a right angle PL259 adapter to mount the antenna on the rear of the transceiver is recommended. It is not recommended that the antenna be used portable when connected to front mounted BNC type sockets. Physical damage to the front panel may occur. The Outbacker Joey antenna is not to be used as a mobile vehicle antenna. Stationary use only. Band Coverage 80m-75m-40m-30m-20m-17m-15m-12m-10m-6m-2m

29 What's good about it - Light weight, multi-bands, breaks down into bite sized pieces, easy band change What's bad about it - relatively expensive, low power, needs radials Source and more information - Probably would only recommend it to an experienced ham who wants multi-band, light-weight vertical, and does not mind radials How long to erect? Less than 5 minutes if pre-tuned Does it need a mast? No, but it will need to be attached to something else How many people to erect it? one This could be a good man-pack antenna.

30 TRI-BAND Super Antenna. You can see their booth at Dayton 2012 here: and their website here: YP3 SuperBeam TM Portable HF-VHF 3 Element Yagi in a Bag TM Price: $ YP3 SuperBeam with BG3 Carry Bag

31 SuperAntenna YP3 SuperBeam Complete Yagi in a Bag 3-element 1 Black padded carry bag 36 inches (92cm) length. Model BG3 Carry Bag. 1 Collapsible Boom, adjustable length aluminum, with boom to mast mount, insulated element mounts 1 Collapsible Driven Element, adjustable length, aluminum/brass fittings 1 Collapsible Director Element, adjustable length, aluminum/brass fittings 1 Collapsible Reflector Element, adjustable lenght, aluminum/brass fittings 12 SuperCoil resonators, threaded to fit elements 1 Driven element matching network, adjustable 1 Banana Jack to 50 ohm BNC coaxial connector adapter 1 BNC to 50 ohm SO-239 coaxial connector adapter 1 Instruction manual 1 Tape measure Weight in bag: 12 pounds Note: This is only a yagi antenna. The tower, mast support, tripod, and coaxial cable are not included.

32 SPIDER ANTENNA Only Truly Modern HF Antenna Made of Long Lasting Materials The Most Versatile Multi-Band HF Mobile Antenna (as many as seven bands, if desired) Ability to Operate Mobile Without Annoying QSB No Need for Antenna Tuner or Matching Network Improved Signal to Noise ratio Top Loading for Better Performance Simple and Easy to Tune Easy-to Read, Weather-Proof, Logging Scale Good Band Width and Ample Power Handling Typical SWR Curves for the Spider Antenna An Ideal Antenna for Restricted Areas No longer in production, perhaps available used on ebay. Has been used as a Dipole during field day, Multiband, with good results. Definitely need an antenna analyzer to dial it in. Somewhat narrow band.

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34 To Calculate Length of Antenna and Radials l = 1/4 WAVE LENGTH f = Freq in MHz ~ 17 FT 1/4 WAVE ANTENNA TAPER TO FIT INSIDE OF POLE l= 243 / f 20 FT CRAPPIE TELESCOPING FISHING POLE 3.00 l = 243 / l = ft or in ~ 48 IN OAK POLE PLUG DETAIL 12IN SPIKE HOME DEPOT ~17 FT 1/4 WAVE RADIALS SMALL BUNGEE CORD TENT STAKE JAY HARLAND AG6JF - 8 AUG METER PORTABLE VERTICAL ANTENNA