6 Meter Halo Antenna Design
This halo antenna by KB1DIGÂ is made with a true Gamma Section this time and is fashioned from aluminum.
Most of the parts are leftovers from old car projects. The best part is it’s omnidirectional!
The 3/8″ fuel-line I used came from Summit Racing Equipment: http://store.summitracing.com #SUM-G2538,
and a 25′ section costs only about $20.oo.
Frank NG1I and Steve N1TYH used aluminum fuel line from a NAPA auto parts supply store.
Welded the elements to the aluminum plate with some of that “Alumaloy” stuff advertised on television.
Alumaloy Sample auction 1/10 pound or 2 rods of alumaloy aluminum repair rods.
Go to eBay: http://www.ebay.com/Â Key words for search: (SAMPLE) Aluminum REPAIR Rods ALUMALOY
I drilled a small hole in one of the elements to allow condensation to evaporate.
Capped off the end of the gamma arm with a plug to keep the weather out. The plug was an automotive type used to block off a PCV line from a carburetor.
After mounting horizontally to a 10′ mast I added a support system made from 2 thin 3′ fiberglass rods and some wire-ties.
Also, remember to hot-glue the wire-ties to the fiberglass rod.
Both 54″ elements are bolted and welded to the mounting plate.
Use galvanized or some other type of corrosion resistant bolts.
The size of the bolts is not so important other then that they fit snugly into the ends of the 3/8″ fule-line and hold the elements in place while welding the elements to the mounting plate.
This “Alumalloy” product is great for this purpose and is more like soldering than welding.
After the 2 elements are welded, leave the 2 bolts in place for added support.
The so-239 connector is pop-riveted to the mounting plate. Face the pop-rivets out and away from the gamma section.
Cut back and expose about 1/4″ of the center conductor of the RG-8 section for soldering to so-239 connector.
Position the 1″ wide aluminum bracket on the Gamma arm, inward about 3 1/2″.
Expose about 3″ of the RG-8 coax center section.
This is just a starting point for matching this antenna.
I was lucky and didn’t need to make any further adjustment for lowering the SWR. The SWR on this design seen here, just the way it is, was 1.2 to 1 at 50.125Mhz.
This halo design is intended to be mounted parallel to the ground.
It should work well for base or mobile operation.
I presently use this antenna at my home QTH and it has proven itself to be quite successful for SSB work. It is presently up on the roof, mounted to a 10′ mast section in a 3′ tripod stand.
It can also be modified to work on the FM portion of the 6-meter band by shortening the length of the 2 main elements a little at a time. I have not done this. No change to the gamma arm will be required if this antenna is altered for 6-meter FM.
This article originally available at http://home.comcast.net/~buck0/6m_halo.htm
Notes on Cubic Quads
Cubic Quads
KQ6RH
(C) 1998, 1999, 2000
Ray Jurgens
(Up-Dated 2/25/2000)Â
 Cubic Quads
 The cubic quad is a very popular way to get reasonably high gain and excellent front to back ratios as well as low angles of radiation for without going to extreme heights. Here I present several designs that that achieve the great performance that hams have associated with this antenna for years. Data are presented for 2 and 6 meter quads and a combined 2 and 6 meter quad that is optimized. The 2 meter 3 element design gets a great 9.5 dBi gain coupled with a F/B ratio of 23 dB.
 Light weight portable cubic quads can be constructed rather easily from fiberglass tubes supported by central hubs. You should be familiar with the material presented in the Quad Loop and Pfeiffer Quad sections of the Antenna Magic page. Cubic quads for wavelengths shorter than 15 meters are easily constructed, however, you should be aware that the weight of these structures is larger by a factor of about 3 relative to most of the planar designs presented in the main menu. Because of this, a heavier mast must be used to support the structure in most cases. Also, be aware that the space needed to assemble and raise a full cubic quad is larger than for the planar designs, and this may be a significant limitation imposed in some locations. In my own case, the backyard associated with my town house is barely large enough to assemble a cubic quad with spreaders of 8′ in length. Wires and guy cords get tangled in the fruit trees, and spreaders hang over into neighbor’s yards. Anything larger 8′ with extended spreaders is essentially impossible to assemble without working above the level of the fence and fruit trees. For that reason, I shall present only two designs which are more or less typical of what can be done easily. The two designs presented are for HF and VHF and should be useful to a wide audience. The HF design is a two element quad for 10, 12, and 15 meters while the VHF design is a two element design for 6 meters with three elements for two meters. A specific advantage of the standard quad design is that multi-band operation is easily accommodated.
5/8 Collinear antenna
I was trying to increase the overall performance of the J-pole, in this design. The diagram provided is a more simplified version of the one I did. These are a few of the modifications I came up with. I added a cap on the top end of the PVC. Mounted a so-239 to a split piece of copper tubing, that took the place of the #14 copper wire. And, I also added a short aluminum mast that fit into the lower end of the PVC.  I mounted the antenna to a 10′ antenna mast and a small tripod on the roof. I tried to add some type of a ground plain but everything I did made the antenna perform poorly. After all my efforts the end result was an antenna that out performs the 1/2-wave colinear copper version, with only one exception. The working model is somewhat narrow banded and still requires more experimentation. Some of the elements must be a little long.
Article originally available at http://home.comcast.net/~buck0/5-8thx2j.htm
The ZS6BKW Multiband HF Antenna
This is the antenna for you guys who want to get on HF effectively, and haven’t too much space or cash to throw around. Actually, it’s a design from ZS6BKW (aka G0GSF), similar to the G5RV, but it actually resonates on five bands, (well 6, actually) and doesn’t rely on a tuner (ATU) to make it work. The design appeared in TT (RadCom) Jan & Feb 1993, but is also in Pat Hawker’s “Antenna Topics” (publ. RSGB 2002) It’s only 90 ft long (27.51 metres), with a 40 ft (12.2 m) downlead.
Horizontal or inverted V layout
So, it’s a cousin to the G5RV (which only resonates on 14 & 24 MHz), but better as it needs no ATU on 40, 20, 17, 12, 10 and 6 metres.
Simple HF Baluns for 50/75 Ohm Systems
The following diagrams and tables show some simple 1:1 and 4:1 baluns for use between 1.8 and 30 MHz using twin transmission lines made from enamelled copper wire (ecw). The bifilar windings have been adjusted (spacing) to produce transmission lines with Zo of 50 or 75 ohms as required for best matching. These designs should be suitable for 100-200 Watt operation.
RF transformers should always operate within safe limits of temperature and linearity. The following designs which use toroid cores can be checked for safe operating conditions with the programs included in Programs.
Materials required:
- Ferrite Core: Select either rod or toroid core as detailed below
- Core insulation: 1 layer of ptfe tape (plumbers thread sealing tape); plumbing and hardware suppliers
- Wire: 1.0 or 1.25mm enamelled copper wire (ecw) as specified; electronics shops
- Spacing material: Kinnears 540 TEX colourfil twine; product code K 069048; newsagents, craft suppliers
- Note: This spacing material is polypropylene; other material is probably suitable, but ensure it will not absorb moisture.
Winding Methods
Step-By-Step Construction of a 4:1 Current-Type Balun
Article by Charles Greene, W1CG
My 4:1 current-type balun is wound on a FT-114-43 core. The FT-140-43 is a little easier to
work with, and maybe the FT-140-77 would cover 160-10. This one is reasonably flat from 4.5
to 35 MHz but drops off a little at 3.5, 40-ohms with a 200 ohm resistor on the high side instead
of the 50-ohms I get on the higher bands.
The reason I used the R/S speaker wire is that last summer Wayne (N6KR) reported his
double Zepp with a R/S speaker wire feed line, and someone at ARRL lab measured the
impedance and came up with around 120 ohms. You are supposed to use something that has
an impedance of approximately 2X the input impedance, and this was close.
Now, to the construction instructions:
Refer to the schematic (or figure 2-1A on page 18 of Jerry Sevick’s book “Building and Using
Baluns and Ununs”).
HF Log Periodic Antenna
A plan for HF Log Periodic Antenna working 10-20 meters band by VA2PHI
Log Periodic Antenna for 10-20 meters bands
Element spacing for a Log Periodic Antenna for 10-20 meters bands
20m Log Periodic Antenna SWR
17m Log Periodic Antenna SWR
15m Log Periodic Antenna SWR
12m Log Periodic Antenna SWR
10m Log Periodic Antenna SWR
Pictures originally available at http://hb9tmw.free.fr/EuroNet/HTML/loghf.html
YOTA 2015 – trip to Florence
Here you are the YOTA 2015 Team while their daily trip to Firenze today.
YOTA 2015 – II5YOTA
YOTA 2015 Italy
Yesterday I’ve been in visit to Marina di Massa for the YOTA 2015, Youngster on the air an International Event by IARU R1.
A total of 76 young hams coming from 22 countries where present
Countries represented, includes Belgium (UBA), Great Britain (RSGB), Poland (PZK), Czech Republic (CRC), Tunisia (ARAT), Croatia (HRS), Spain (URE), Netherlands (VERON ), Sweden (SSA), Austria (OeVsV), Serbia (SRS), Estonia (ERAU), Slovakia (SARA), Hungary (MRASZ), Finland (SRAL), Montenegro (MARP), Bosnia-Herzegovina (ARABiH), Oman (Roars), Ireland (IRTS), Bulgaria (BFRA), South Africa (SARL) in addition to the hosting country Italy (ARI).
It has been a nice experience, and really make pleasure to see so many youngs still interested into ham radio.
Read more about YOTA 2015