- Use simplex wherever possible freeing the repeater for necessary uses.
- Monitor the repeater (listen) or determine if the repeater is in use, and if there are any peculiarities in its operation. After listening for a few seconds, identify, un key and listen to see if it was quiet for a reason, and to allow someone to let you know if there is a reason not to continue (low audio, low signal strength, etc). Then, if all OK, proceed.
- Donâ€™t break into a contact unless you have something to add. Interrupting is no more polite on the air than it is in person. Interruption without identification constitutes malicious (and illegal) interference.
- Use the minimum power to key up the repeater. To make contact, simply indicate that you are on frequency . For example “IW5EDI monitoring”. Do not kerchunk.
- Remember amateur radio transmissions are being monitored by many non-hams with scanners. Watch your language and your manners. Please don’t bring disrepute on the Amateur Radio Service.
- Repeaters are intended to facilitate mobile and portable operation. During rush hours, base stations should relinquish the repeater to commuting mobiles. Some repeater owners have strict rules requiring this.
- Keep transmissions short and thoughtful. Do not monopolize the repeater. Pause between transmissions to allow other amateurs to identify themselves if they wish to use the repeater. Pausing also allows the timer to reset, avoiding a “time-out”
- Identify legally. In Canada that means at the beginning and end of a contact and every thirty minutes of operation.
- Repeaters are installed and maintained at considerable expense and inconvenience. Regular users of a repeater should financially support the individual or club owner in their efforts to keep the repeater working properly.
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 auctionÂ 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.Â 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.Â 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.Â 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.Â I have not done this.Â 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
(C) 1998, 1999, 2000
Â Cubic Quads
Â 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.
Â 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.
I was trying to increase the overall performance of the J-pole, in this design.Â The diagram provided is a more simplified version of the one I did.Â These are a few of the modifications I came up with.Â I added a cap on the top end of the PVC.Â Mounted a so-239 to a split piece of copper tubing, that took the place of the #14 copper wire.Â And, I also added a short aluminum mast that fit into the lower end of the PVC.Â Â I mounted the antenna to a 10′ antenna mast and a small tripod on the roof.Â I tried to add some type of a ground plain but everything I did made the antenna perform poorly.Â After all my efforts the end result was an antenna that out performs the 1/2-wave colinear copper version, with only one exception.Â The working model is somewhat narrow banded and still requires more experimentation.Â Some of the elements must be a little long.
Article originally available at http://home.comcast.net/~buck0/5-8thx2j.htm