The UH Ham Club has managed several activities recently, most notable has been several operating sessions from McCarthy Mall, which makes up the center of the UH Manoa campus.
The purpose was to simulate emergency communications on battery power from an outdoor location. The equipment consisted of a TenTec Argo 556 transciever, a 10 Amp Hour Gel Cell battery, an MFJ QRP Portable antenna tuner/SWR meter and an improptu antenna system.
For some time we had speculated that fire hydrants would make ideal grounds. A major problem with any endfed wire antenna, random or not, is that the tuner used needs a very good ground, either as a big radial system or a very good cold water pipe or series of ground stakes. Well, a 30-inch, cast iron water main attached to a fire hydrant has to qualify as a fairly major cold water pipe!
Some convenient palm trees near a hydrant just Mauka of Kennedy Theater was an ideal setup. I used my antenna launching kit consisting of an underarm throw weight, and a small slingshot to put the string up and over the exact center of a palm tree in relatively few tries. It is important to put the string right over the center of the tuft of fonds on the top of the tree to get any real support.
The below photo shows some ideal antenna supports (very tall palm trees in the clear), and a wonderful ground, a nice fat fire hydrant which I know is connected to a 12 inch water main that runs down the length of McCarthy Mall. The building in the background houses the computer center. Nothing is perfect. But hash from the computers on 40 meters does not seem to be a problem. Most of the clocks are screaming away above 6 meters now days, or even 220 Mhz.
A modified gluing clamp was used for the fire hydrant connection, the type that is like a huge metal clothes pin. The plastic tip protectors were removed and the tips bent so they were parallel. Then a heavy wire was attached to both jaws of the clamp for maximum contact area. Using a jumper to short both jaws firmly together instead of relying on the hinge for contact helps a lot.
About 60 feet of wire were hauled up on an insulator to the top of the right most palm tree and from there sloped down to the fire hydrant and the tuner. At 40 meters about 65 feet of wire is a half wave, and thus a high impedance voltage fed antenna at that frequency. Such a setup requires a very good ground to keep RF off the equipment. But this setup passed the "hand on the tuner" test easily, indicating no RF on the gear.
Much attention was attracted by this weird activity and the Campus Security Office received no less than 18 frantic calls the first time reporting weirdos, anarchists, deviates all trying to blow up fire hydrants and pull down palm trees.
It was interesting to note that the various humanities and other soft science types around could only imagine the worst of terrorist activities when viewing a huricane preparedness drill. There appears to be a downside to having windows in such offices.
Campus Cops arrived soon after. By that time we were on the air with the Hawaii Afternoon SSB Net. We showed ID's (the heavy duty permanent faculty/staff kind) explained we were a Registered Independent Organization of the University of Hawaii at Manoa (time for official titles for sure) and they listened with great interest to the hams from the Big Island and Kauai etc. coming out of the speaker before leaving us alone.
The second time we tried it out was during Christmas break and we attracted much less attention and the Campus Security fellows did not bother to stop by. One person did rush up and ask if were were getting ready to blow something up. I think it is a humanities/soft science mindset when presented with obvious high tech hardward in an outdoor setting. Maybe they were frightened by Mr. Wizard when they were children or some other psycho/science trauma. Anyway...
Signal reports with the antenna wire, fire hydrant and 3 watts were good to great the first time. The second time band conditions went sour during the net time since it was in late December. But 30 minutes before the net we had a long QSO with a Big Island station with fine signal reports, however.
Other activites so far have included joining the KARC group for a tremendous amount of fun at their 1997 ARRL Field Day site where we set up a QRP single operator field day entry and a true long wire to experiment with [Summer 1997]. We did not do that well, but we did learn a great deal. We are very much looking forward to heading back out to the KARC field day site again this year with our QRP station and vastly improved antenna designs.
Part of the problem was an inadequate ground. A 34 foot length of wire on the ground was added as a counterpoise, but this did demonstrate that even with 250 feet of wire or so in the air, if it is not properly worked off a decent ground or counterpoise system, you are just heating components. This is something you cannot afford to do at QRP levels. You cannot waste any of your power output if you can help it. The end fed wire needs a decent ground reference on the tuner.
A small tent has been secured for an operating station and our very own propane lantern so we will not have to use Walt's. We may even fly a kite antenna this year at one of the two sites! Subsequent testing has show the propane lantern puts out tremendous heat and alternate lighting for night operation is being worked out.
The KARC group were a great bunch to join up with for field day. Sitting up all night by the glow of a lantern in one of Hawaii's great parks pounding brass on a picnic table is one of the great joys of life. High wind gusts and rain every 20 minutes, flapping tarps and even 800 singing Christians on a campout across the road, cannot dampen the fun. When the singing gets too loud, you just hook up the microphone and start calling CQ Field Day! "Kumbaya" on enough 12 string guitars in the background can, however, introduce a calypso swing into your fist on CW, and get lots of comments on SSB.
We were extremely thankful for both the large commercial tarp canope of the KARC group and the smaller home brew one of Walt's. There were rain squalls all night long, often coupled with bursts of high wind. But a little preparation made things pleasant and easy to cope with. At least there were no mosquitos under these conditions. Any of those that dared try to fly, found themselves near Kauai in short order. It is alleged that the mosquitos in this park have insignia on the wings and carry unique squadron tail numbers. I was glad they were grounded by the weather.
We are definately planning another field day QRP operation this year along with helping with the KARC field day effort. I understand a large camp area has already been reserved, so preliminaries are already under way. This year the Christians specifically asked to have a weekend "when the hams were not going to be there." Strange.
Plans are in the works for a test campout in February to scout trees (suitable for antenna supports), test antennas and shake out tents and other supplies. I have a fantastic SLV portable vertical system that I hope to configure as a pair of full size phased verticals on 20 meters. Also I have a large parafoil kite that given adequate wind, pulls like a team of oxen, and a design for a 40 meter J-pole for it to loft. So many toys, so little time...
The field test, QRPTTRF, went very well, see alternate page.
The SLV system is working out extremely well thanks to a decent ground system. The coils by Vern are a work of art.
The Stake Stick antenna system is also working very well for portable use in spite of its small size and needs more trips to city parks for testing, especially as 15 meters opens up. This antenna based on Hustler whip components and a special ground mounting had surprising performance, especially on the higher bands in initial testing.
The 40 meter J-pole experiments have been a disaster so far and need more prototyping. It is not not clear why the J-pole antenna tests have been such a failure, but some new ideas need testing. It should be an ideal kite lofted antenna system.
The winds have so far been rather uncooperative for kite testing. The winter has been dry and the trades weak. However, we have in hand several large classic lifting kites, including a big Buffalo Box Kite, a classic winged triangular box kite and a large parafoil. Any of these is capable of lofting quite an antenna given steady and reasonable winds.
Several other interesting activities are open this summer as possible club projects. One is the "Flight of the Bumblebees" sponsored by the Adventure Radio Society, for which we have already been invited to participate. You can check out their web page for details on this contest.
The other is a special celebration of lighthouses, lightships and Ham radio which will feature operation in late August of 1998 from lighthouses and lightships. The Diamondhead lighthouse will be 100 years old this summer and will be a perfect site, if access can be arranged for this special event.
08/99