President's Message 

by Randy Hammock KC6HUR

[Written in December 1993. Note: President Bob, N06B, is working on an *especially* good column for the next newsletter.]

Thanks to Les White, KN6JU, for assistance in getting the new air conditioner installed in the shack. After fighting an aged unit for several years, Facilities gave us a new (used) air conditioner. In the process of installing the new unit, a hole was drilled through the wall and Les installed a pipe and dress panels through which all of the cables that used to run past the air conditioner are now run.

The equipment that we ordered to replace the damaged equipment on the Mesa is starting to arrive. We will be putting together some work parties in the near future to run the new hardlines and rotator cables from the Mesa to the shack, and to install the rotators, antennas, and tower on the Mesa. We still need to do a small amount of electrical work in the shack to install some 240V outlets for the linear amplifiers and get the shack back into some semblance of order and usability.

Randy Hammock KC6HUR

 

OUTGOING PRESIDENT'S MESSAGE

The past two years have been quite interesting. I have been proud to say that I was President of the JPL Amateur Radio Club. I can recall reading about the JPLARC in "73 Magazine" over twenty years ago and thinking how neat it would be a member of that club. Funny how dreams have a way of coming true.

Things haven't all been good, but then they haven't been all bad either. Over the past few years, the sources of club funds have certainly changed. The club used to make a fair amount of money at the ERC picnic and was able to get fairly good funding in the form of matching grants from the ERC. Now there is no more ERC picnic hot dog sales fund and the grants are for much smaller amounts (a reflection on today's economy). However, we have been able to secure funding from other Lab sources and have raised dues to help cover the slack.

With the merging of the Goldstone ARC with the JPLARC, we now have twice as many repeaters that must be maintained. This means that we now have to spread our funds over a larger area and that there is a greater need for membership involvement.

This brings me to my final item. There have been several members who have been giving outstanding service to the club. Some of their members have been with the club for years while others have been members for a few months, but for a club with over 200 members, we are certainly lacking the support of the members (paying your dues is nice, but it is not enough). In the next couple of months, we will be having work parties to rebuild our antenna system on the Mesa. There are a few work days necessary to complete installation of the antennas and new repeaters at the Mesa repeater site. The 224.080 repeater is also in need of some major repairs to restore full functionality. Once we get everything working on this side of the hill, there is the refurbishment of the Table Mountain site, new linking facilities from Table Mountain to the Mesa and remote receivers for 224.080. The shack needs lots of help to restore it to a world class operation once the Mesa antenna farm has been completed. All these projects need bodies as much as they need money.

I once put out a message to ask for help and received 2 replies of which one was an offer of help. I threw up my hands and said "To hell with 'em, let the system fail and once the level of necessity rises, perhaps we'll get some offers of assistance." Well, after a couple of months, still no offers but I'm ready to go back to work and hopefully things will be back to normal. What am I talking about? The .080 repeater, of course. If things appear to be changing too slowly for you, don't offer your complaints, offer you assistance.

Now that I can dedicate more time to some of the club's projects, I hope they can be moved a bit faster.

73 and Happy New Year, Randy Hammock KC6HUR

[Let me add that one of those members giving outstanding service to the club is none other than Mr. Randy Hammock, KC6HUR, himself - kd6msm]

 

EDITOR'S SOAPBOX

During the recent fires above Altadena and Sierra Madre, ham radio was there. Hams used local repeaters' including our club's, to maintain contact with their friends and families, coordinate evacuations, in some cases coordinate fire fighting (NW6H!), report problems, and just in general check up on each other and make sure we were all OK In cases where phone service was out, or overloaded, autopatch machines allowed phone calls to relatives and public safety agencies.

After we had secured our pictures and irreplaceable mementos (and a few radios) and sat back in the smoke filled air of Altadena to watch the fire advance inexorably across the mountain face, I thought about how ham radio had fit into the scheme of the fire in general. Except for a few cases where hams helped non-hams with autopatch calls (I think those people had lost their homes), I did not hear anything that suggested that we were part of the activities in Altadena. I thought about the things we could have done, like helping the Sheriff's and Fire Departments with manning roadblocks, coordinating the engine companies that were rotated out for rest did not know where they were going, or maintaining a communications center with the Red Cross to assist people in getting messages out to their loved ones. Maybe all these things and more were done and I just did not hear about them. Or maybe they were not necessary because other institutions were able to pick up the slack. After all, as overwhelming as they seemed, the fires were strictly local affairs. I am not sure what we should have done, but I think we need to know next time what our part is. One last thought, and that is that for these "local" fires, engine companies and law enforcement from all over the state were brought in. In the event of a major, region-wide disaster such as an earthquake, such resources will not be available, and we will be on our own.

It has been awhile since you last saw W6VIO Calling. Fires, and then problems with getting files transferred to my PC at home have delayed things. Then the stories I get early wind up being outdated, and I have to go ask for updates. What I try to do is reach "critical mass" of articles and then prepare them for Art Zygielbaum to format into a newsletter. I really need submissions from members. I will say again that they do not need to be polished, just informative. I do not mind editing. In this issue Ron Zenone W6TUZ has written an article on refurbishing an older vertical antenna to give it new life on the WARC bands. Thanks, Ron, for taking me seriously. There is more to life than packet, and our club members have a wealth of information and experience on all facets of amateur radio, be it antennas, contesting, DX-ing, VHF/UHF, packet, ATV, EME, satellites, you name it. Now if they would only share it with the rest of us!

Coming up in our futures issues, Jim Szeto KC6WIK has promised a series of articles on the new TCP/IP packet Internet gateway now undergoing test operations in the shack. What can *YOU* tell us about?

73 de Greg KD6MSM

CalTech Amateur Radio Club

by Greg LaBorde, KD6MSM

Caltech has its own amateur radio club, W6UE, with impressive HF facilities on the campus and a UHF repeater. Caltech's club emphasizes DXing and HF contesting, and W6UE has racked up an impressive record in both arenas. Club President Mark Beckwith, WA60TU, and VP/Secretary/Treasurer Dave Ritchie, N6DLU, have participated in several DX-peditions. I myself have seen the QSL cards in OUR (JPL's) shack! About 20 people attended the recent W6UE club meeting held on 10/13/93, including several JPL club members.

Dave Ritchie solicited program ideas for future meetings. Since most W6UE club members belong to other clubs with more "mainstream" programs (like Gordon West, or The Condor System), discussion focused on subjects particularly relevant to UE’s DX and contesting interest.

We expect to have that a talk by Mark and Dave on their recent DX-pedition to Hawaii at a forthcoming club meeting. This was a "doable" DX-pedition, that neophytes such as myself might be able to imagine ourselves doing. This in contrast to the Curacao Mega-DX-pedition that was one of the first presentations I saw at the JPL club.

W6UE also operates a UHF repeater in the Pasadena area with good coverage of the entire basin. W6UE/R is an integral part of the Caltech emergency response plan, and will also serve as an important link between the campus and the Lab. Membership in W6UE is available to JPL ARC members. Anyone interested can write the Caltech Amateur Radio Club at Campus mail stop 218-51.

 

1993 CLUB BANQUET

by KD6MSM

Once again, the annual JPL ARC banquet on December 8th was a smash success. Held at the Acapulco Restaurant in Pasadena near FedCo, there was scintillating conversation, breaking squelch, interesting personalities, good food, beer, margaritas, lots of all of the above, and best of all, CHEAP! We had several invited guests this year, including Jean lannitti of 641, who handles our procurements for us, her boyfriend Axel, and Larry Dumas, Deputy Director of JPL (for those of you who did not know). After a tension-filled period of terse talk-ins resembling peak-period Air Traffic comms at LAX, we settled down to consume the excellent (and did I mention CHEAP?) Mexican dishes produced by the staff of Acapulco.

As the meal wound down, it was time for election. Three of the officers elected were conveniently not present for the election. The fourth was distracted. Election chairman Manny Caldera KC6ZSY assured us that all had agreed to the nomination. Officers for 1994 are:

PRESIDENT Bob Dengler, N06B
VICE-PRESIDENT Richard Schick, KE6BKE
TREASURER Scoff Balzer, KC6NRP (re-elected)
SECRETARY Greg La Borde, KD6MSM (did I agree to this?)

Wish them well. It is a dirty job but somebody has to do it.

That out of the way Manny introduced our speaker and dinner guest, Dave Glawson WA6CGR. For you who do not read QST and therefore were unable to read it for yourselves on page 104 of the December 1993 issue, Dave recently set a new distance record of 1019 km for 10 GHz from Point Sal, California (CM94pv), working with Jack Henry XE2/N6XQ on the Vizcaino Peninsula in Baja California, Mexico (DL27ul). Dave used a 1.25 W system with a 69 cm dish and Jack used a 3 W system with a 76 cm dish. Both systems were home-brew. Quoting QST (and Dave): "Contact was made August 23 at 1600Z with signals peaking 20dB out of the noise."

Dave dazzled us with a computerized presentation of pictures and tape-recordings of his record-setting effort. One interesting thing he mentioned was that the received signal's polarization was rotated approximately 30 degrees from horizontal and held steady. He also challenged us to prove that 10 GHz is "line-ofsight." Then he discussed the equipment for 10 GHz, and the vast chunks of spectrum available above 1 GHz. He said that it is not that hard to get on-the-air at 10 GHz, but it takes effort and time since most equipment is home-brew. Test equipment or access to it is vital, but there are many microwave experimenters out there willing to help. Dave opened up his 10 GHz rig to display design and construction as precise and clean as anything that comes out of a JPL fab shop. A very inspiring talk, thank you Dave.

Dave left me copies of several articles he has written, including "An Improved Microwave Source Locking System" and "A Complete X-Band SSB Portable Communications System." Both articles are very well done and anyone interested should call me at 354-0230 for a copy. Who knows? Maybe it is time the JPL ARC blazed some trails above 2 GHz.

In all, a good time was had by all.

ANNOUNCEMENTS

MESA WORKDAY 12 FEBRUARY 1994

There will be a workday at the water-tank antenna site on the Mesa on Saturday 12 February 1994 at 0900, barring closure of the Mesa for repaving. This workday will be to bury PVC pipe under the access road to run coaxial and rotor cable through for the HF and VHF antennas up there. If you recall, the tower at the water tank site was destroyed during the construction of the city's water tanks, and the hardlines were flattened by repeated encounters with heavy equipment. Picks and shovels are needed.

220 SMA RESHUFFLES 220 BAND

With the incorporation of the 150 kHz sub-band from 222.000 - 222.150 MHz, the 220 SMA has to reshuffle repeater coordinations to relocate the repeaters whose inputs are displaced by the move. The 224.040 W6VIO repeater may be one of those that has to change frequencies to accommodate the reshuffling. Stay tuned for more details.

CLIPPERTON AMPLIFIER NOW ON LINE AGAIN

The Clipperton amplifier is on line once again. The RF chokes and parasitic capacitors on the plates had burned. Then the tubes went flat. Jan, WB6VRN, bought new tubes and Mark, WB6CIA, replaced them. "The SWR was good so I hit the switch and there was no smoke (Mark). The amplifier is *NOT* to be used on the WARC bands. This would produce instant smoke.

Reminder!

JPL Emergency Communications Team Net

Mondays -- 12 Noon 224.080

 

DX News

By Bob N6ET

The low bands are back and chuck full of exciting DX as we progress through winter. 40 and 80 meter long path openings at sunrise and sunset are especially productive with openings on both bands to the Middle East available daily. 80 meter openings are best exploited with an antenna with gain (as compared to a dipole). 40 meters can be enjoyed with a simple dipole! 20, 17, and 15 meters are also exciting during daylight hours. Now for a few specifics:

BRITISH VIRGIN ISLANDS - Look for VP2V/W2GUP from 23 January through 17 March. He plans mostly CW operation on all bands near the low end or up 25 kHz.

GHANA - XT213W will be operating from 9G-land from February through April. He's a great CW operator, showing up primarily on 20 CW.

MIDWAY ISLAND - KH4/N7TNL is very active on local Saturday and Sunday afternoons around 18086 kHz and in the middle of the 12 meter CW band (24905 kHz).

PETER I ISLAND - 3Y??? will be active from 1 to 17 February. This is the most needed country on the current DXCC Country List. Specific call and frequencies will be posted on the W6VIO shack wall when they become available (probably the next DX Bulletin issue). They should be workable on all bands.

PRATUS ISLAND - Was activated briefly a few days back for four hours at a time with no US propagation. A full-scale operation is hoped for in the March timeframe. If we're lucky' this may become a new DXCC Country. The call is BV9P.

RWANDA - 9X5HG is joined by 9X5DX from this relatively rare location. He is active from 1300Z on 21024 kHz. Rumors have 4X/S59PR as possibly moving to Rwanda as his next assignment. Look for him on the low end of 40 CW if the move takes place before the end of the current fantastic early morning conditions on 40 meters.

TOGO - 5V7JB operates Fridays on 21220 kHz from 1700 to 1730Z.

TROMELIN - FR5ZQ/T should be active during the month of January. No reports yet, but 20 and 40 CW should both be possible this time of year.

WESTERN SAHARA - Look for S0RASD on 21258 kHz from 1730 to 1830Z. S0LMZ is active on 14202 kHz at 1930Z.

My thanks to the DX Bulletin for providing most of the source material for this DX News article. Good DX!

Repeater News by Bob Dengler, NO6B

It has been a time of antennas in the JPL ARC repeater committee. Chris Carson KE6ABQ and Curtis Byrom KD6IFU went to TMO on October 10 to install a new antenna mount to replace the broken mount holding the 145.28 and 223.96 repeater antennas. These are expensive antennas, and if it weren't for these people we probably would have lost at least one of them this coming winter. While I wasn't there myself, I understand that Chris spent over six hours on that telephone pole trying to secure a couple hundred pounds of steel support structure. MANY thanks to you Chris, & also to Curtis for putting together the custom-made support structure. Because of these repairs, the 145.28 repeater at Table Mountain has now regained its original coverage pattern; base stations in many portions of the L.A. basin as well as Nevada, the Owens Valley & the San Joaquin Valley are once again able to use the system. We have received some complimentary reports and thanks from users in the LA Basin and the desert.

Figure 1: Initial Configuration

On the home front, we have received many antennas that will be installed on the Mesa soon. One of these antennas, the new Celwave 4-pole for the 147.150 repeater, has already been installed. Many of you have been wondering why the western & southwestern coverage of this system had been so poor. The reason is that the former antenna for this repeater was a 4-element Yagi beam pointed southwest. The cardioid pattern of the 4-pole antenna will significantly increase the usability of the repeater by club members. Many thanks to Jan Tarsala WB6VRN and Sam Weaver WB6EMO for getting the antenna mounted on the Mesa telephone pole. The 4-pole is now mounted below 224.040's Super Stationmaster as shown in Figure 1. Later a new pipe will be added to the pole to raise the Super Stationmaster up about 20', and the Celwave will be raised to stand above the telephone pole as shown in Figure 2. Jan had an interesting observation on the health of the telephone pole. He noticed that the mount for the 224.040 antenna is secured to the pole with simple lag screws.

Figure 2: Final Configuration

On Thursday, 11/4/93, the Sinclair duplexer for the 147.150 W6VIO repeater was returned to its real owners, the West Coast Amateur Radio Club. We had borrowed the duplexer for several years, and it was time to return it. Our new Celwave duplexer is now installed along with an Angle Linear GaAs FET receiver preamplifier. Some fine tuning of the receiver remains, but the 147.150 repeater is back on the air with initial reports of a vast improvement in coverage. Power output has been reduced to a low level because our low antenna was radiating into the I-lan group's repeater. When the antenna is raised to its new height full power will again be possible.

The 10/28/93 windstorm that led to the Altadena, Laguna, and Calabasas blazes also impacted the club. Here is a report from Randy Hammock, KC6HUR:

With all of the high winds we have been experiencing of late, the club has suffered a casualty. The antenna on the 224.080 repeater is ready to fall off the top of the pole where it is mounted.

THE SITUATION

Last night (27-OCT-93) Manny KC6ZSY and I went up to inspect the situation. Here is what we found:

The bottom mounting bracket of the antenna has broken off or come apart leaving the antenna held by the top mounting bracket only. The antenna has fallen over in the remaining bracket and has twisted it so that the antenna is resting at an angle of about 45 degrees towards the West. Due to the poor condition of the pole, we expect the top mount to twist out, causing the antenna to fall in the next high wind. Should this occur, there is the possibility it could fall onto the antennas belonging to the City of La Canada and/or any number of antennas on the building/tower structure.

Randy moved repeater operations to the spare Super Stationmaster antenna at the site, the unused control receiver antenna (frequency donated to UPS), by installing an N-connector to its cable. This antenna is lower than the main antenna, so repeater coverage will be affected somewhat. Subsequent to that report, during the 11/14/93 windstorm, the main Super Stationmaster antenna did fall from the top of the pole. It was blown OUTSIDE of the fence around the building, carrying away the coaxial cable to the Civil Defense siren located there. The antenna broke in half when it hit the ground.

Operations will continue on the spare antenna, and preparations will begin for mounting the Scala antenna already on-hand to the top of the pole. Experience gained in mounting the 2m antenna will help to make this job smoother. Parts for a new mount will have to be procured and fabrication started. We will need help for this job, especially pole climbers.

JPLARC SENDS CONDOLENCES

TO GERRY WALSH, KB6OOC

The Jet Propulsion Laboratory Amateur Radio Club sends its condolences to Gerry Walsh, KB6OOC, and his family for the passing of Gerry's father on Monday, January 17th. Gerry's father had been Ill for some time, yet his sudden loss came as no less a shock.

For those of you who do not know Gerry, he is the highly capable SysOp of our packet BBS and an APT in Section 333. Many club members have expressed their regrets and offered Gerry any assistance that they can give. Also, expressions of sympathy from area hams who know Gerry from the packet arena have been arriving on JPLBBS.

The earthquake has been a time of loss for many club members and coworkers. Our condolences to everyone who has suffered a loss.

MORE ANNOUNCEMENTS

HF ROTATORS TO BE REPLACED

As part of the effort to refurbish the Mesa HF antenna system, both rotators will be replaced. The Somer antenna's rotator took a lightning strike and the water-tank rotator was damaged in the fall. Both rotators will be replaced, this time with connectors in the line to allow ground testing.

MEMBER MAILING DATABASE

The JPL ARC member mailing database is NO LONGER MAINTAINED BY THE ERC. Please send any information (updates, address changes, new consigns, etc.) to Rick McKinney, KA6DAN, at m/s 168-327 (x4-3968).

VANITY CALLSIGN PROPOSAL

Jay Holladay, W6EJJ, discussed a proposal before the FCC to allow "vanity consigns" to be issued to US amateur radio operators. The associated fee would be $7/year, paid in advance, for any unassigned call out of the group(s) appropriate to the requester's license class. This would include callsigns freed up by amateurs who had previously upgraded or moved (when a change of call-district required a new callsign). There would perhaps be a "grace period" in which amateurs could recover their old calls. Jay is looking for comments from club members for input to the ARRL, for their use in preparing a response to the proposal. Contact Jay at x4-7758 or m/s 171-243.

 

Save That Old Vertical

Inexpensive Rework Adds 17 and 12 Meter Capabilities.

by Ron Zenone W6TUZ

Many of us start out in the hobby of ham radio by putting together an HF station that includes the very popular vertical antenna. I started out that way in the mid 1950s. I continued using those beauties and bought my third vertical in the early 1980s, an HF6V antenna manufactured by Butternut Electronics Company.

While most hams consider antennas to have special sight appeal, non-hams do not generally appreciate them as artistic compliments to the appearance of a house. Consistent with this generality, my wife would periodically drop hints to me that the roof-mounted vertical with its counterpoise (approximately 60 radials) was an eye-sore to her as well as to our neighbors. I downplayed the appearance and touted it as being temporary. Fortunately for me she was quick to forget.

Although vertical antennas did an adequate job for me, I dreamed of the day that I would have sufficient time and funds to incorporate a tower and directional beam antenna into my station.

A time came when my wife suggested that we add on to our house. Even though it was a great idea, my antenna would have to come down for the construction. I thought that perhaps I could negotiate the sacrifice of the vertical antenna for the installation of a tower and directional beam once construction was completed.

We struck an agreement and tore down the antenna when the construction contractor was about to start. Eventually the construction was completed and my tower and beam were in place. I could then operate again on the 40, 20, 15 and 10 meter bands.

Shortly thereafter' my 70s vintage transceiver (repaired by me several times) began exhibiting new problems. Tired of making repairs to my vacuum-tube rig, I opted to procure a modem solid state transceiver. Within a couple

of months after getting the new rig I began feeling that I wanted to expand my band capabilities and try out some of those WARC bands that my old equipment and new beam antenna could not operate on. I now had a capable transceiver, but no suitable antenna.

Center Freq. (MHz)	Calculated Length	Final Length
3.885	Adj. 80M Coil	Adi. 80M Coil
10.125	23'5"	23'5"
18.118	131"	13'21'
29.940	9'6"	10,101,

Table 1: Calculated and Final Lengths of Stubs and Total Antenna

I decided that I would add an antenna to my station at minimal cost, so I sought out and located the HF6V antenna. It had been stored for a couple of years behind some bushes near the house. Inspection revealed that the antenna had experienced some very hard times. Two of the coil and capacitor assemblies had been smashed by someone's feet or from placing a heavy object on the antenna. Most of the capacitors were cracked and completely useless, with only the 80 meter coil and capacitor assembly undamaged; However, the basic framework of the antenna was still intact.

I decided to clean it up and incorporate modifications that would enable me to work the 80, 30, 17 and 12 meter bands that my beam was unable to handle. The success that I had in modifying the vertical inspired me to write this article with the hope that it might inspire others, such as you, to experiment with vertical antennas and consider making inactive antennas operational again.

Before you make any physical change to the antenna, make yourself a diagram of the antenna that specifies all significant length measurements and tubing outside diameters. You then need to recondition the antenna by taking it apart and cleaning all metallic surfaces that make electrical contact with other metallic surfaces. Some cleaning supplies I found that worked great included a fine bristled wire brush, emery cloth, and steel wool. While reassembling the antenna, you will probably want to coat the outside surface of tubing that slides into larger tubing with a conductive anti-seize paste sold at most radio supply stores. This will allow better long term antenna performance and will permit you to adjust it or take it apart years down the road much more easily.

The original HF6V incorporated a resonant quarter-wave stub de-coupler for the 15-meter band. The stub decoupler operates as a radiator and isolates the upper portion of the antenna while operating on that band. This technique is straightforward and makes construction and tuning relatively easy to accomplish. The stub de-coupler concept intrigued me and I wanted to capitalize on the simple method in altering my antenna. The existing stub support bracket located near the top of the antenna had to be modified so that it would accommodate a second braided wire for the 17-meter band. I readily adapted the existing 15 meter stub de-coupler for 12 meters by shortening its length. I soldered the new 17 meter braided wire stub to a lug ring terminal and attached it to the stub support bracket with a nut and bolt.

The original HF6V design used spacers to support the braided wire stub and electrically isolate it from the antenna tubing. Since I was adding a second stub (for 17 meters), it was necessary to fabricate additional spacers. I used surplus Plexiglas that I had on hand in the garage.

Making them was relatively easy using simple tools such as a hack saw, electric drill and file. Be sure to make the hole through which the tubing passes slightly under-sized so as to obtain a tight fit between the tubing and spacer. This will prevent the spacer from slipping and disarranging the braided wires when the antenna is exposed to strong winds. The antenna resonance points will be more stable, precluding (or reducing) sporadic jumps in VSWR during windy conditions. I used a Plexiglas piece attached to a homemade aluminum clamp to tie up the bottom portion of the additional braided wire and to keep the wire taught at the desired length.

Next you need to select a design frequency for each band you are interested in and calculate quarter wavelengths for each band. The frequencies that I chose, initial calculated lengths, and final measured lengths after operational adjustments are listed in Table 1. The method of calculating quarterwave antenna and radial lengths is straightforward and conventional. I have used the following formula over the years with success:

1/4 wavelength length (feet) = 237/F (MHz)

Figure 1. Basic dimensions for the modified vertical.

As seen in Table 1, in all cases but one my calculated lengths were fairly close to the final adjusted values. I cannot explain the exception for the 12 meter band. Initially I had a very difficult time finding the resonance point.

I would not have been readily able to adjust the antenna if - it were not for measurements taken with an antenna bridge and digital frequency counter loaned to me by loaned to me by Jerry (W6WXL). This equipment allowed

me to find the actual resonance point located considerably outside the 12m band. Once I determined the resonant frequency, I recalculated the new length and adjusted the stub to bring the resonance point to the desired center frequency. You can save time and reduce the number of adjustment iterations by using the following mathematical technique to recalculate for new lengths:

New Length (feet) =

Length Measured (feet) x Resonance Frequency Measured (MHz)

Desired Resonance Frequency (MHz)

Figure 1 shows overall details of the completed antenna. Notice that at the antenna feedpoint I placed an RF choke consisting of seven turns of coax feedline formed into a six inch diameter coil and held together with electrical tape. I wanted to preclude degraded performance by taking advantage of the RF choke's capability to suppress the flow of RF along the coax shield of the transmission line. The improved performance resulting from such a minor amount of additional work is well worth it.

Since I once again planned to roof-mount the antenna, I needed a radial system that was low profile and visually tolerable to my wife and neighbors. I intentionally limited the number of radials to four per band to achieve this without excessively compromising performance. I calculated the lengths of the radials for the higher frequencies using the formula listed above. I was initially concerned that 64-foot radials for the 80 meter band would be a problem. This dissipated once I recalled the many articles in ham magazines over the years about effective shortening of antennas with linear loading techniques. This technique of linear loading also applies to radials, reducing the length to a more manageable forty-three feet. Figure 2 shows how simple constructing a linear-loaded radial can be. The three-wire antenna rotator control cable I used is easy to find and reasonably priced. After making one-time adjustments for 80, 17 and 12 meters, the VSWR for each of these bands was quite acceptable. 30 meters required no adjustment for

Figure 2. Dimensions for 80-meter radials.

acceptable performance. As you might expect, 80 meters exhibited narrow bandwidth but could be centered to a desired portion of the band by adjusting the 80 meter coil. Without using an antenna tuner, measurements made at the transmitter end of the coax feedline showed VSWR better than 1.3:1 across the entire 12, 17 and 30 meter bands.

Before modifying my vertical, I had observed little activity on the WARC bands. With the newly modified antenna in place I found the bands to be busy; signals appeared to' jump out at me when I started scanning these bands.

On-the-air performance of the antenna for receiving and transmitting has been better than expected. I found no difficulty in making CW and SSB contacts on these new (to me) bands. Although I have only operated for a short time with the modified vertical, I made more than fifty contacts during a two week period. I have received signal reports that compared favorably with those that I gave, except for those contacts in which the other hams were using beam antennas and/or linear amplifiers. The broad bandwidth of the antenna on the WARC frequencies made jumping between the bands with my solid-state rig a breeze.

The antenna has survived winds that exceeded 75 miles per hour and continues to function well, even in heavy rains.

Changes to an existing antenna can be easy and inexpensive to incorporate. Results obtained with the modified antenna and the satisfaction gained in knowing that you did it yourself can add more to your enjoyment of the hobby, as I have found.

The technique of using multiple stub de-couplers for additional bands of operation is not limited to the HF6V; It can be applied to other vertical antennas. Reducing the length of the 80 meter radials through the technique of linear loading appears to work well also and can be considered a viable approach when radial size is a concern.

One last word: do not hesitate to investigate other techniques and experiment with antennas, for you too will find the spirit of experimentation is as much alive in hamdom today as ever.

 

SpaceNews Items from SpaceNews

*MIR OPERATING HINTS *

This Week: Automated calling programs for packet radio communications Several people have asked me what are the best programs to use that will automatically call Mir and the Shuttle while I am not at my station. My first response is: Are you that lazy? But really these program should be called Automatic QRMing Programs, because that is what they do best. You should NEVER use an Automatic QRM program to call Mir or the Space Shuttle. I have yet to see one of these programs that is smart enough to shut-up and not cause QRM. (in theory it is possible to develop an automatic calling program that would generate minimum QRM.) On October 3, 1993, a station in New York left his Automatic ORMing program running all day while the operator was away. The result was that no one East of the Mississippi was able to reliably transfer any data to Mir for the whole day. This was because the Mir PBBS was too busy sending <<DM>> (DMDisconnect mode) frames to the New York station. I counted over 120 DM messages to just this one station in one day. What are the legalities of using such a program, since the Mir PBBS can only connect to one station at a time? Any station with excessive connect attempts while the PBBS is connected to someone else, is causing Intentional Interference and may be subject to FCC fines. The bottom line is be courteous to other operators and never use an Automated Packet calling program for Mir or the Space Shuttle. Remember, one station can connect to Mies PBBS at a time. others must wait. [Story by G. Miles Mann, WF1F]

* ARSENE FAILURE *

The ARSENE satellite is no longer responding to telecommands sent by the FF1STA command station at ENSAE School in Toulouse. Numerous commands have been sent to try to reactivate the satellite without success. Since September 9th at around 00:00 UTC when ARSENE signal was last heard in mode S, controllers have not received any more telemetry from the satellite. The transmission stopped at the moment ARSENE was moving out of a one hour eclipse period. Contrasting with was earlier thought, the SHF power output stage temperature never reached more than 42 degrees Celsius before entering into the Earth shadow. The temperature dropped by ten degrees when in the eclipse part of the orbit. The FF1STA command station was able to observe telemetry data indicating that the automatic system for handling eclipse power conditions was working fine. All collected telemetry data before the failure is carefully being investigated by ARSENE experts. There will be an attempt made to recover ARSENE using the FC1ELL EME station in Argenteuil near Paris, with an 8m dish and high power UHF transmitter. [info via Bernard, F6BVP]

* OSCAR-11 FAILURE *

Controllers at the UoSAT Control Centre at the University of Surrey are requesting the help of the amateur radio community around the world in collecting information and data from UoSAT-OSCAR-1 1. The Forth Diary Operating system aboard UO-11 has crashed. This has rendered the spacecraft in a non-nominal operating state. The collection of information and data related to the operational condition of the spacecraft will be essential in helping the controllers to understand the spacecraft's current condition. Therefore the UoSAT command team is asking radio amateurs around the world to monitor the spacecraft and relay any reception reports and or telemetry data collected from the spacecraft to them via G0SYX @ UO-22, G0SYX @ KO-23 or via the Internet address: D.Loughmiller@ee.surrey.ac.uk. UoSATOSCAR-11 operates on a 2M frequency of 145.826 MHz and on a 70 cm frequency of 435.027 MHz. Controllers are most interested in which beacon is active at the time of any given observation and whether the signal contains data or not. Any telemetry data collected would be of particular interest to the controllers as well. Any observations provided by the amateur community will be most appreciated. UoSAT controllers will issue subsequent bulletins about the status of the UoSAT OSCAR-1 1 spacecraft as the situation develops.

{Info via K0511GOSYX and the AMSAT News Service]

Date: 3 Feb 94 23:11:21 GMT
From: ABFHB@STDVAX.GSFC.NASA.GOV
- Organization: ucsd usenet gateway
Subject: STS-60 SAREX Flight Begins
---,4,B SAREX @ AMSAT $STS-60.001
STS-60 SAREX Mission Begins
3 February 1994 at 12:30 UTC

The Space Shuttle Discovery made a spectacular, historic, on-time liftoff this morning from the Kennedy Space Center. Discovery's launch marks the first joint U.S.-Russian Space Shuttle Flight. This will be the first of several joint missions planned in preparation for the development of the international Space Station. Cosmonaut Sergei Krikalev, U5MIR, was one of the six crew members on board this morning's Shuttle flight. His fellow American crew mates include Commander Charlie Bolden, KE41QB, Pilot Ken Reightler, and Mission Specialists Jan Davis, Ron Sega, KC5ETK and Franklin Chang-Diaz. The primary payloads on-board Discovery are the Wake Shield Facility, which will be deployed and retrieved during the flight and the Spacehab facility. Of particular interest to radio amateurs is the Shuttle Amateur Radio Experiment (SAREX) secondary flight and the Spacehab facility. Of particular interest to radio amateurs is the Shuttle Amateur Radio Experiment (SAREX) secondary payload. SAREX information for STS-60 including frequencies, callsigns and Keplerian elements, follows:

STS-60 Shuttle Amateur Radio Experiment (SAREX) Information Sheet

Mission: STS-60 Space Shuttle Discovery, Wake Shield Facility & Spacehab-2 Mission

Launch: February 3, 1994, 12: 10 UTC

Orbit: 57 degree inclination

Mission Length: 8 days (Nominal)

Amateur Radio Operators: Charlie Bolden, KE41QB, Ron Sega, KC5ETH, Sergei Krikalev, U5MIR

Modes: FM Voice; Prime callsign KE41QB

Packet Radio: Callsign W5RRR-I

Frequencies: All operations in split mode. Do not transmit on the downlink frequency.

Voice Freqs:

Downlink 145.55 MHz (Worldwide)

Uplinks: 144.91, 144.93, 144.95, 144.97, 144.99 Mhz (Except Europe)
               144.70, 144.75, 144.80 MHz (Europe only)

Note: the crew will not favor any, specific uplink frequency, so your ability to work the crew will be the "luck of the draw"

Packet Freqs ;

Downlink 145.55 MHz

Uplink 144.49 MHz

Info ;

Goddard Amateur Radio Club, WA3NAN, Greenbelt: Maryland, SAREX Bulletins and Shuttle Retransmissions: 3860 KHz, 7185 KHz, 14,295 KHz, 21,395 KHz, 28,650 Khz and 147.45 MHz (FM) 

Johnson Space Center ARC, W5RRR, Houston, Texas SAREX Bulletins: 7225 KHz, 14,280 KHz, 21,395 KHz, 28,650 KHz, (SSB) and 146.64 MHz am 

ARRL Amateur Radio Station, WlAW, Newington, CT SAREX News Bulletins: 3990, 7290, 14,290, 18,160, 21,390, and 28,590 Khz and 147.555 NlHz (FM)

Also, bulletins available on internet, via AMSAT ANS, Compuserve, and your local PBSS.

School Group Participation 5 school groups will participate in SAREX with pre-scheduled direct and telebridge contacts. These include 4 in the U.S., and one in Russia.

STS-60 Keplerian Elements

STS-60
1 22977U 94006A 94035.13981770 +.00000202 00000-0 58718-5 0 37
2 22977 56.9857 213.2731 0008535 263.0773 96.9324 15.72145611 115

Satellite: STS-60
Catalog number: 22977
Epoch time: 94035.13981770            (04 FEB 94 03:21:20.25 UTC)
Element set: GSFC-003
Inclination: 56.9857 deg
RA of node: 213.2731 deg               Space Shuttle Flight STS-60
Eccentricity: 0.0008535                    Keplerian Elements
Arg of perigee: 263.0773 deg
Mean anomaly: 96.9324 deg
Mean motion: 15.72145611 rev/day  Semi-major Axis: 6730.8981 Km
Decay rate: 0.20E-05 rev/day*2       Apogee Alt: 358.25 Km
Epoch rev: 11                                  Perigee Alt: 346.77 Km

Posted September 25, 1999