Meeting Minutes - July 29, 2006

Nixa Amateur Radio Club, Inc.
Meeting Minutes
July 29, 2006
Call to Order
Chris Cochran, KB0WZC, called to order the regular meeting of the Nixa Amateur Radio Club, Inc. at 18:05 on July 29, 2006 in Nixa Fire Station.
Roll Call
Jeff Kerr, KC0VGC, conducted a roll call via a sign-up sheet. The following persons were present:
Member Present - 16:
James Adkins, KB0NHX Jim Adkins, KC0IYI
Kim Adkins, KC0 David Bowman, WB0QIR
Chris Cochran, KB0WZC Matt Ellif, KC0QJJ
Dean Gaines, KC0SQD Al Gallo, W0ERE
Bob Hessee, N0XJJ Jeff Kerr, KC0VGC
Jeff Morrissey, KB0WVT John Perkins, W6OQS
Chris Raymond, KC0TLE Doug Schumpert, K0DPS
Jeremy Tannehill, KC0UJZ Rich Vogt, KB9YZE
Guest Present - 6:
Ralph Baldi, KF6AHT Ray Cadmus, W0PFO
Pat Conway, WA6JGM John Kreymer, N5LKM
Terry Shoemaker, KE4LQW Richard Spurlock, N0UBX
New Members Joined - 3:
Ralph Baldi, KF6AHT Ray Cadmus, W0PFO
John Kreymer, N5LKM
Approval of minutes from last meeting
Jeff Kerr, KC0VGC, provided a copy of the minutes to the president for posting to the club website.
Open Issues
A. Repeater Linking:
It was discussed as to how the 2-meter and 6-meter repeaters should be linked, and if it should be linked full time or not. It was decided that the 6-meter and 2-meter repeaters would be linked for the Thursday net, now dubbed the N.A.R.C. Network, into the evening and on weekends (Saturday and Sunday).
B. 6 Meter Repeater PL Tone:
The 6-meter repeater PL tone has been turned on for the 6-meter repeater. This has been done to try to eliminate some interference that has happened late in the evenings and early in the mornings. These occurrences have been rare, but now that the repeaters are linked it would be good to try to eliminate any possibilities of this happening in the future and affecting both repeaters.
C. Club Garage Sale:
Jeff Morrissey, KB0WVT, brought up the idea of having a club garage sale as a possible fundraiser. This would not be limited to ham radio items but any and all items that could be sold. Any leftover items from the garage sale would be donated to an organization like the Council of the Blind. This event is being targeted for the October time frame. Details on the event are to be discussed further at a future meetings.
D. Club Sponsored Golf Tournament:
This would be the second annual "Communications Classic" club fundraiser. It was felt that much was learned in running the tournament last year and that we could be more successful with another tournament this year.
E. Treasurer's Report:
Jeff Morrissey, KB0WVT, presented the treasurer's report.
F. Christian County ARES Presentation:
Terry Shoemaker, KE4LQW, and Pat Conway, WA6JGM, presented. It was brought to the groups attention that the IS-700 class is going to be required for anyone that is going to be involved as a responder in any civil emergency. It was also brought to the groups attention that any and all licensed amateurs are welcome to join Christian County ARES regardless of any past or present affiliations with any other club or organization. Christian County ARES is actively seeking new members to help fill their ranks as to better respond to city and county emergencies when called upon to do so. Pat Conway gave a detailed description of harmful interference that is being caused on the 145.230 repeater by a nearby wireless Internet service provider. The wireless provider is cooperating with Christian County ARES to resolve the interference issue. Right now the interference is overloading the front end of the repeater resulting in poor receive performance.
G. Allstate Foundation Grant:
Patty and Chloe Dixon from Allstate Insurance in Nixa presented a check to Chris Cochran, KB0WZC, on behalf of the Allstate Foundation in the amount of $500.00. The club gave a whole-hearted "thank-you" and applause to Patty and the Allstate Foundation for the generous contribution to our organization in recognition of the Club's commitment to public service and emergency preparedness. Patty Dixon's Allstate Insurance office is located on highway 14 (Mount Vernon) between Sonic and Nixa Convenience Center.
H. Repeaters:

James Adkins, KB0NHX, presented the following information on the club's repeaters:

6-Meter Repeater (53.270 MHz / PL 162.2)

The 6-meter repeater continues to operate well. We've had a few isolated incidents of interference.

Yesterday, James Adkins, KB0NHX, and Jeremy Tannehill, KC0UJZ, went to the 6-meter site and installed fans on the UHF link radio and the backup 6-meter repeater making them both capable of 100% duty cycle. In addition, some minor re-programming was done to the controller and link audio was further adjusted.

With the Allstate foundation grant of $500 and sale of a GE Rangr radio and the sale of the batteries we were going to use for the 145.270 backup battery that we ended up not needing, we have made enough to cover all charges associated with the 6-meter repeater. Thanks again to Chris Cochran for covering the bill until these items could be moved.

All, I'd like to give a brief account of the install of the repeater and how it operates.

The install went pretty well. The only snag we ran into was the fact that PDQ bid half as many coax cable hangers as we needed. On a normal tower, spacing is one hanger every 4 feet. On CU's tower, it's every 2 feet. The reason for this is that CU's tower has a higher standard they must live up to. More hangers = better windloading characteristics. We were 110 1-1/4" hangers short, and about 90 7/8" hangers short. Thanks to Jeremy and Alltel for coming up with the 90 7/8" hangers, saving us several hundred dollars. We did, however, have to purchase the 110 1-1/4” hangers at a price of $340, which put us over the top on the budget. They had to be drop shipped from Andrew overnight, and the shipping cost almost as much as the hangers!

Here are some samples of the 6-meter coax. The smaller diameter coax is 7/8" heliax, and we have 400' of it running to our UHF link antenna, which also serves as remote control and will serve as the receive antenna for the remote receive audio when those go on the air. The larger coax is 1-1/4" diameter heliax and we have approximately 450' of it running up to our 6-bay DB-212-C-3 antenna system. I'm going to pass around some pictures now of the 6-meter antenna mounted on the tower and of the UHF antenna used for linking now, courtesy of Jim Adkins, KC0IYI. The climbers were on the tower almost 8 hours installing all this coax and the antennas. The big moment was the SWR test after the install. The UHF antenna was only specified to work up to 420 MHz, so going up to 425 MHz left me wondering how good it would be, even though the engineer at Andrew said it would be fine. SWR at the Link frequency ended up being a measly 1.3 to one, very acceptable. As for the 6-meter antenna, SWR there is 1.6 to 1. A little higher than I'd like, but due to the nature of the install which forced us to move bays closer together and farther apart at 2 points due to guy wires probably affected the SWR. When the antennas are mounted closer together, it causes the whole system to have a higher SWR. I'd like to see no higher than 1.5 to 1 on a repeater, but I feel 1.6 to one is acceptable on transmit. Way down on the receive frequency, we’re at 2 to 1. Better than I expected as the antennas only have a 1.2 MHz bandwidth for a 1.5 to 1 SWR reading. What helped us was the fact that the antenna was actually resonant at 53.000 MHz instead of the 53.270 MHz. This helped our receive SWR and hurt our transmit SWR.

As of now, squelch opens at .15 uv with a good strong 20 db quieting signal at .25 uv and the CDM750 radios are using 50 watts to drive our Henry 300 watt PA to 250 watts out of the radio. We are getting 185 watts out to the antenna system, with virtually no loss in the 1-1/4" coax our ERP is near 750 watts.

Now we'll show some of the pictures of the install.

At the top, you'll see the Henry Amp, which gives us 250 watts out for 50 watts drive. Just below it we have two Astron RM-60M power supplies. One power supply is for the backup repeater radios. The second power supply is the main supply and provides power for the main Motorola CDM750 transmitter and receiver and associated fans, the CDM1250 link radio and the CAT-1000B controller. Below the second power supply is the main or primary 6-meter repeater. It consists of one CDM750 for transmit at 50 watts and a second CDM750 for receive. If these were to fail, the receive radio is programmed to where it can act as a transmit radio and the transmit radio can also be a receive radio. That in conjunction with the second set of CDM750 radios means we literally have 4 transmit radios and 4 receive radios that can be used in any configuration. So, we should have a repeater on the air even if one or two of the radios fail.

Below the backup 6-meter CDM750's is the brains of the repeater. It's the CAT-1000B repeater controller. It provides all the audio handling between the transmit, receive and link radios and handles commands for remote control via UHF. Lastly, we have the UHF CDM1250 radio that provides 45 watt output and allows us to link to any other repeater that would like to link in via UHF. In my opinion, this works better than linking on VHF to other repeaters on the repeater pairs because of the special audio handling that can be done on the link port and also because it allows you to connect to many repeaters at once instead of one. To the right of the equipment you see the duplexers, 4 cans about 6' tall and 4" in diameter that allow for simultaneous transmit and receive. To the right of them you have the dual bandpass cavities, that measure 8" in diameter and 8' tall. These notch out all frequencies close to the receive frequency and are needed to help cut out close by interfering signals and the 250 watt transmitter. All this equipment, of course, has top of the line Polyphaser protection via the coax and AC lines and the cabinets of the equipment are tied into the MGB as well to minimize down time due to lightening strikes.

UHF Link Radio System:

The UHF link radio transmits and receives on 425.300 MHz. Right now, the 145.270 repeater is set to link into the 6-meter with the linking codes. The 145.270 site also utilizes a CDM1250 radio, running 20 watts and using a DB-436A yagi antenna with RG-213 coax and polyphaser connection to link to the 53.270 site. What is neat about this linking system is that ALL links will be able to be activated through the 6-meter repeater with this setup. In other words, all someone has to do is get into the 6-meter machine to bring up the link to the 145.270 repeater, or any other repeater on the link. That means you don't have to access the 145.270 on UHF or 2-meters, or be in range of either, to link the repeater. That is a big bonus to our mesh-style link. We hope to be able to link Joplin 147.210 in for weather as a backup at first then possibly as primary method of linking and also utilizing EchoLink as well when needed. As you can see, the possibilities are almost endless. Questions about the link setup?

2-Meter Repeater (145.270 Mhz / PL 162.2):

James Adkins and Jeremy Tannehill installed a 19" rack mount shelf, courtesy of Alltel, at the 2-meter site. This shelf holds the CDM1250 Link radio and the Peet Brothers UT-100 weather station. A fan was installed on the link radio as well for 100% continuous duty cycle if needed. While there, all the old switching network that switched us from AC to battery was removed and wiring was cleaned up as well making the site much more friendly to the eyes. The only thing reliant on 120 volts AC is the Peet Brothers weather station. In the future, James and Jeremy plan on running it directly to 12 volt DC as well once a DC cord can be fabricated. This will be at no cost to the club as we have parts on hand to make the cable. The link audio has been turned down from the 6-meter site as of this time. It sounded like it was a tad hot. Give us reports on what you think.

70-Centimeter Repeater (444.275 MHz/PL 162.2):

In talking with Jeremy Tannehill, KC0UJZ, the Alltel tower will be going up just south of Nixa in the coming months. Diddier Wireless Towers is going to do the building and install at the site and Jeremy thinks they may be able to install the antenna for us at no charge if we have all the parts. Basically, we lack the DB-420 antenna and the coax hangers, connectors, hoist grip and grounding equipment. About $1500 worth of equipment at new, full price. Jeremy suggest that we run the coax and purchase a cheaper fiberglass antenna just to get it ran. If going this route, we would need less than $500. Any comments on this project?

New Business
No new business was presented for club vote.
Chris Cochran, KB0WZC, adjourned the meeting at 20:25.

Minutes submitted by: Jeff Kerr, KC0VGC

Minutes approved by: Chris Cochran, KB0WZC