Welcome To The Benton County Radio Operators Monthly Get Together

SPECIAL NOTICE The August 2015 BCRO club meeting has been rescheduled from Tuesday, August 11 th to Wednesday, August 12 th, at the usual 7pm to 9pm. The September 2015 will be on the 2 nd Tuesday of the month at 7pm.

WELCOME TO MEL’S DOG AND PONY SHOW I’M MEL HAGEN AF5GF

CHARACTERISTICS OF RANDOM LENGTH AND LONG WIRE ANTENNAS

FOR ALL PRACTICAL PURPOSES THEY ARE BOTH THE SAME

To make the antenna work on multiple bands, you need to avoid multiple half wave lengths at any frequency.

Random wire antennas can be made to work well, but you MUST understand how they work. HALF of the antenna is the ground system! With a poor ground, such as a single ground rod, you will lose almost 50% of your power in earth losses. Reason: dirt is a very poor conductor of RF current. THAT is why you need radials or a counterpoise system. (A counterpoise is a ground system NOT connected to earth ground). Since the antenna literally comes into your shack, it is VERY important that you do have a good RF ground or there is a decent chance of RF in the shack at anything more than modest power levels. If you do have RF in the shack it simply means your ground system is inadequate or presenting a high impedance. Some wire lengths will be easier for the tuner to find a match on than others. However, generally, random wires are pretty easy to match. The length of your counterpoise will vary the impedance of your antenna.

THESE ARE THE BEST LENGTHS IN FEET TO USE

Previously I stated that you will be bringing the antenna wire all the way to your antenna tuner in your radio room (the shack), this is not necessarily the best way to connect the antenna to your transmitter. You want to avoid bringing R.F. potential into your radio room at all cost. IT CAN BE PAINFULL IF YOU COME INTO CONTACT WITH IT. More on this later.

The easy part of determining an acceptable antenna length has been worked out for you. I refer you to the following URL.

This chart will help you out for the next few pages GroupUSA Bands a b c d e f

OKAY! Now, let’s move on to the safe way to get your antenna connected to your antenna tuner. Here is your parts list: 1 each banana plug 2 conductor Landscape wire (for the antenna) [Lowe's Item #: | Model #: ] 12 inches of 2 inch diameter PVC pipe 2 each of 2 inch diameter PVC pipe caps 1 each SO-238 UHF connector, female-to-female 1 & 1/8 “ long. UHF PL-259 male coax connector RG-8X coax [as needed]

HERE ARE YOUR INSTRUCTIONS In the end of one of the PVC caps drill a hole just big enough for your coax cable WITHOUT the connector to fit thru SNUGGLY! Pull 5 to 6 feet of the coax thru the PVC cap (it will make sense in a few minutes). Split the landscape wire into 2 separate wires. Drill a hole in the remaining PVC cap to fit the landscape wire SNUGGLY! Pull 3 to 4 feet of landscape wire thru the PVC cap. 18 inches from the end of the wire you just put thru the PVC cap, make a knot in the wire. Now you cannot pull the wire out of the PVC cap. Strip the end of the wire to solder it into the Banana plug. Pull the wire out of the PVC plug to the knot.

Now, back to the coax With your coax thru the PVC cap, install a PL-259 UHF male connector on the coax. Do not, for any reason, use a twist on connector. Use a good quality connector. Now that the coax has a connector, screw it onto the SO-238 female-to-female adapter. If you used a 12 inch PVC pipe, push the pipe into the antenna wire PVC cap with about 6 inches of antenna wire dangling out the bottom of the pipe. Push the banana plug into the open end of the female- to-female adapter. Pull the coax snug to it’s PVC cap. Push the pipe into the coax PVC cap. DO NOT GLUE THE PVC CAP’S TO THE PIPE!

If the antenna wire and the coax are a snug fit do not worry about rain water getting into your PVC assembly (I refer to this as the interface) and corroding your connectors. The PVC caps will fit snug enough to keep them on without glue. You do this so that if you need to do maintenance in the interface you can get to the inside without cutting the 12 inch PVC pipe!

Now, to answer your question that you’re ready to ask. WHAT ABOUT THE SHIELD SIDE OF THE COAX? Inside your “shack” you will have all of your equipment connected to earth ground. By now you will probably have your antenna hanging from the sky, ready to use. Get enough additional landscape wire to run the full length of your antenna. Bury the landscape wire 3 to 4 inches in the ground under your antenna. MORE LANDSCAPE WIRE: run a length from your earth ground to the underground wire. This is necessary with coax instead of bringing your antenna into your “shack. You now have your counterpoise installed under your antenna! Antenna engineers will argue the point about grounding your counterpoise to the shack ground. It improved my reception by 3 to 4 “S Units”.

SPECIAL NOTE FROM ME TO YOU If your coax run is going to be longer than 100 feet I highly recommend using LMR-400 instead of RG-8X. When you are all done with everything and you have used a recommend length of antenna, your tuner should be able to give you an SWR of 2:1 or less. Don’t expect an SWR of 1.25 to 1. IT AIN’T GONNA HAPPEN!

The BCRO 2-meter Repeater Is located in Centerton, Arkansas The frequency is with a negative offset of MHz and a PL tone of Please join us for our BCRO Net meeting every Thursday at 7:00 PM Please join us for our BCRO Elmer’s Net and BCRO Swap and Shop every Saturday at 11:00 AM Everyone is welcome to join us even if you have no club affiliation Our web site is:

THANKS FOR COMING DRIVE HOME SAFELY SEE YOU NEXT MONTH