Prague 2002 is only a little over a month away, and as reported last month will be one of the best attended EME Conference of all time. You don't want to miss this one! However, Dan, OK1DIG warns that reservations for accommodation in the EME conference hotel will be definitely closed on July 3! Any other later attempts for accommodation must be directly with the hotel and will not receive the discount and free rooms guarantee provided by the conference. For details see:

Please keep the news and technical information coming. I will be looking for you off the moon.

73, Al - K2UYH

EME Schedules

JULY 13

Time     432.040

0900z  DK3WG -JA3SGR
0930z  DK3WG -JH7PAV
1500z  OK2BDQ-DK3WG
1530z  LU7DZ -DK3WG
1600z  W4ZRZ -DK3WG
1630z  W1IPL -DK3WG
1700z  K6IBY -DK3WG

When my xyl's family announced a reunion in Omaha, NE set for 15 June, it presented a chance to give some of the EME group a shot at getting a new state for their WAS. Instead of using the airlines, we could rent a van and drive to Omaha. K2UYH had loaned us his 20 foot portable dish, which we had tested on a simplified polar mount. This plus the 432 MHz TX, RX, etc. would easily fit in the van. But before we made serious plans for the trip, an impromptu survey was conducted on the Moon-Net asking how many needed Nebraska on 432 MHz EME.for WAS. The result was surprising. Very few from the 432 group responded, whereas there were many, many heartbreaking pleas from the 2-m gang. It appears that NE has not been on 2-m EME for perhaps a decade or so. And the KA0RYT operation a few years ago must have taken care of most of the 432 people. This altered the planning for the trip. We had 2-m equipment from our satellite operations of many years ago. A TX using pp 4CX250B's, a MGF-1302 preamp, transfer relays, etc., and the FT-767GX had the 2-m plug-in. The antenna was an old Telrex 8-element Yagi. It was FB for satellite work, and I did raise W5UN on random during one of the EME contests. But I needed something much bigger for the trip to NE so as to give most of the EME hopefuls a reasonable shot. I called the M2 Antenna people and spoke to Mike, K6MYC. He was sympathetic to the project and agreed to loan us two of his 2MXP28's with the power splitters, crossboom, etc. These would be drop-shipped to the site in Omaha in time for the operation. The site in Omaha was arranged by an old friend, W0LHZ. Joe is a member of the 300-member Aksarben Ham Radio Club. As is K9RZ, Bill Jackson, who has a 3.5 acre, HF dxer's dream location on top of a hill, which would provide essentially unimpeded coverage of the moon from moonrise to moonset. Bill and his XYLl, Karen, N0KWH, agreed to host the operation from 6/14 through 6/16. We would setup on 6/12 and 6/13 and takedown on 6/17. So the plans were in place to operate both 2 m and 70 cm EME stations at the QTH of K9RZ. Since the XCVR and power supply were common to both systems, simultaneous operation would not be possible.

While preparing for the trip, Mr. Murphy showed up. I had not used the 432 system for several months so I thought a routine check before packing it for NE was in order. While answering a CQ from KL6M, the PA flashed over and blew the high voltage fuse. One of the pp 4CX300A's was damaged. I put in the spare set that I intended to take to NE. The same problem occurred about 30 minutes later when I was calling K9SLQ. I put out a call for help with 4CX300A's on the Moon-Net and K2UYH responded with three and WA0TEM sent several more. After cooking the filaments for many hours, I found two pair that were a little flaky when pushed a little, but did not blow fuses. I did not feel too comfortable and was wondering, if the operation should be called off. About this time, Al, K2UYH, said his old amplifier had been repaired by K2AH and could be used as a backup unit. I drove to the Jersey shore and picked up the 7650 PAS. Tom does not have a 432 driver so could not hot test the unit. He did, however, use a signal generator to set the tuning controls about right. The tetrode has its screen at chassis ground for stability and its grid bypassed in a grounded-grid configuration. I made a quick modification to the HV PS to provide the proper screen voltage using VR-150 regulator tubes. When the PA was fired up, the screen was drawing very heavy current and output was nil. During discussions with Tom on the phone, it was thought that perhaps the tube was bad, but that Al had spares. However, Al was on a business trip and would not be back before I had to leave for NE. Tom suggested I take the amplifier with me and if I could make further checks to pin it down to a bad tube, maybe Al could overnight a spare to NE.

While the above was going on, I pulled the 2-meter amp from the relay rack and to my surprise I found old 4X150A's in it and the output was way down. I had forgotten that I had sold the 4CX250B's years ago. I could not quickly find any 250's locally and Surplus Sales in Omaha was out of stock. RF Parts in CA did overnight a pair of Svetlana's which worked FB. I also had to order LMR coax, adapters, control cables and all the bits and pieces that would be needed for the 2 m station. The coax adapters were misdirected but arrived in time.

With so many things on a shaky footing, I was still considering calling off the operation, but it was late in the game. The M2 antennas were on their way to NE and many people were looking forward to a contact with a new state on EME. If Murphy would ease up a little and we had some luck in Omaha, I felt it would be worth the effort. So we packed the van and the XYL and myself took off for Omaha via I-80.

Before we hit the road, we made reservations for overnight stops along the way and for our stay in Omaha. We were jolted by the news that the College World Series was going to start in Omaha the weekend of our operation and that all hotels/motels were completely sold out even for miles around the city. We managed to get accommodations in the small town of Blair, which is about 17 miles north of Omaha but not too far from K9RZ.

The 1200-mile trip took three days and we arrived in Omaha on schedule; 6/12. The next morning, we were joined by Aksarben club members at K9RZ. The van was unpacked and work started on erecting the dish and installing the TX/RX, etc. The 20 reflector panels are constructed of 1-inch chicken wire held in place by frames of wooden strips. Progress was slowed by entangling of the Dacron fish line strings that hold the reflector panels in place. A photo of the antenna on its polar mount was included in the Nov 2001 issue of the EME NL. Its F/D is about 0.5. The driven element is a 1-wl circular loop in front of a 0.62-wl square reflector. Spacing was adjusted for a VSWR of <1.1, which was about 0.13-wl. The HF-400/2Z transfer relay and MGF-4819D preamp are mounted in a plastic box behind the reflector. Separate coax lines are run to the TX and RX. An additional preamp was used at the RX to make up for line loss.

The two 2MXP28 antennas from Mike at M2 Antennas were more of a challenge than originally anticipated even though Mike took the time to color-code the elements and boom locations. This certainly helped, but mounting them to the crossboom and then to a tripod mount required some ingenuity. Several trips to Home Depot and home workshops finally got the job done. The tripod was about 5' high which meant that with some droop in the booms the vertical reflector elements were just above ground with an elevation angle of about 5 degrees. VSWR was checked at <1.1. The polarity switching relay, TX/RX transfer relays and MGF-1302 preamp were mounted on a piece of plywood attached to the tripod at the crossboom. Separate coax runs were used for TX and RX. The array was setup pointing at moonrise. It was hoped that several stations could be worked before the moon rose above the beam pattern. If results were encouraging, several plans were under consideration to raise the height of the crossbeam and therefore, the ability to elevate the beam. One idea was to mount the tripod on top of the van, but the windy conditions on K9RZ's hill would have made this a risky proposition. When we were unable to hear anyone including KB8RQ, we tried to rough check the beam pattern by passing a hand-held through the beam in the far field. Reflections, scattering and blockage led to inconclusive results. It was then discovered that the horizontal driven elements had been inadvertently set out of phase. The vertical elements had been installed properly. The problem was corrected for the Sunday moonrise when several signals popped out of the noise. K9TI was 539 on peaks and we attempted to raise him but could not make the connection. We later found that he had heard us also. Someone said that we were on the wrong frequency. The signals were gone after a short time and probably the result of ground reflection boost. A near miss but no cigar.

Wind conditions kept the tie-down ropes on the 432 dish for Friday, 6/14. My memory is hazy as to what other things happened and when. It seemed we were tackling one problem after another. Some were minor annoyances, but they still cut into valuable operating time. The relays used in the 2 m system were Dow Key series 60 of 1970 vintage. All contacts had been burnished, but one of the high-isolation connectors got stuck in the grounded position and could not be broken loose. Fortunately, I had brought a spare connector. But it took some time to sort through boxes to find it and replace the bad one. On 432, the PA was acting up intermittingly. However, the backup unit was unavailable. It had been opened early on to check the 7650 tube for shorts between internal elements. At least under cold conditions there were none. A quick inspection did not reveal any obvious problems, so further trouble shooting was put off until returning home. On Saturday I left operations on 432 in the good hands of Joe, W0DB and Bill, K9RZ, while I attended the family reunion in Omaha. When I returned, they reported two significant happenings. First, a sudden wind storm nearly destroyed the dish. It took their efforts along with Karen to hold the tie-down ropes to avert disaster. Second, the D-26-N brick used as a driver had severely overheated. When it cooled down, it again acted normally, which is just coasting along to drive the 4CX300A's. However, it was a fore warning of further trouble on Sunday. The intermittent problems with the 432 PA appeared to be tube related so the tubes were replaced in pairs as the unit is operated push-pull. This is not a "lift the lid and plug in the replacement" type of operation. The entire tank circuit has to be dismantled to get at the tubes, which seemed to take forever under the circumstances. Then, at one point the brick broke into sustained oscillation with very high current and quickly overheated. I have used the driver for many years without any problems, but Murphy had struck again. The unit was opened after cooling down a bit, but there was no sign of transistor damage or other indication of trouble, except the heavy connections from the input/output connectors and the board grounds looked suspiciously cold-soldered. These were resoldered using lots of heat and fresh solder. When the system was fired up, the TX seemed to be acting normal for the first time, but it was late in the game. It was time for the last scheduled station, K0RZ. About this time, K2UYH phoned and asked to be added to the end of the list at 0000z. K0RZ was worked and then several stations tail-ended which cut in to Al's scheduled time. Knowing that he had his WAS, we ignored Al and worked WA4NJP and then KL6M. Following this we looked for Al, but apparently we were behind his trees or he had given up on us. Joe, W0DB did the operating during this period. Bill, K9RZ, who was our official liaison with the sked coordinators and the net, announced over the Moon-Net that we would be calling CQ on 432.030. When we got no takers, the operation went QRT.

I think we tried to cram too much into a fixed window of opportunity. As stated before, it was a great disappointment not to have worked more people, especially those needing Nebraska for the last state or two. We do hope that the expedition will result in an EME station operating from NE on a regular basis.

73, Warren – W2WD