Mon, Dec 17, 2018
Log in Register

Login to your account

Username
Password *
Remember Me

Create an account

Fields marked with an asterisk (*) are required.
Name
Username
Password *
Verify password *
Email *
Verify email *

January 2004 Board Meeting

Minutes of the Board of Directors Meeting of

The Rib Mountain Repeater Association

11 January 2004

Weston Fire Department Building, Weston Wisconsin

 

The meeting was called to order circa 19:45 by President KC9NW.

 

Present were, KB9VBR, KC9NW, and K9DB.

K9PT was absent with the flu, and KC9UC could not attend due to a prior commitment.

 

The first order of business dealt with a proposal by K9DB regarding the re-establishment of the 146.04/.64 repeater on Rib Mountain. The written proposal as submitted follows:

 

 

Proposed Modification to the RMRA Repeater System on Rib Mountain

4 January 2004

 

Proposal:

  • The RMRA should move to acquire from WAR the 146.04/.64 repeater allocation for Rib Mountain surrendered in 2003 by the WVRA.
  • The RMRA should install a second 2-meter repeater on Rib Mountain on this frequency pair. The transmit/receive antenna should be mounted on the northwest leg of the candelabra at the approximate 125-foot level on the RMRA bracket previously occupied by the Business Service Center.
  • A capability should be installed that will allow both repeaters to be linked or unlinked upon command.

 

Reasons for Proposal:

  • With the 146.22/.82 repeater antenna installed to the southeast of the east leg of the candelabra, a substantial amount of RF “shading” from tower support structure and feedlines can be expected to the northwest. The resulting antenna pattern nulls can be expected in both transmit and receive. A second repeater, with antenna lobe maxima pointed to the northwest will provide coverage in the nulls. When viewed as a single system, the two repeaters will accomplish omni-directional coverage using side-mounted antennas.

 

  • Reactivation of the 146.04/.64 allocation for Wausau will prevent proximate systems on this frequency (primarily Juneau WI, Winona MN, and Hoyt Lakes MN) from increasing system ranges by power or antenna height allocation increases, thereby limiting the configuration and performance parameters of any future Wausau allocation of this frequency pair.

 

Operational Advantages:

  • During operations requiring wide area coverage such as severe weather, ARES, and other nets, the repeaters will be linked. Stations at all azimuths from Rib Mountain will have reliable transmit/receive access. User would have the option of operating on .04/.64, .22/.82, or run a non-standard split of .04/.82.

 

  • At times when the repeaters are not linked, the .04/.64 repeater will be available for local traffic, or non traditional programming such as IRLP, code practice,  NASA audio, news, lectures, etc.

 

Engineering Concerns:

Of primary concern is interference and subsequent degradation of the performance of the 146.22/.82 system. This interference, primarily 146.22 MHz receiver desense, can be mitigated by some or all of the following actions:

o  Maintaining vertical separation of the antennas. The antenna heights as proposed would provide about 160 feet of vertical separation.

o  Establishing horizontal shielding. By adjusting the angular position of the mounting brackets, the tower structure and commercial feedlines can be used to shield the two antennas from each other.

o  Reducing of power output of the 146.64 transmitter. The WVRA ran about 100 watts into the antenna. Initially, this transmitter could run 10 – 20 watts.

o  Employing more sophisticated isolation measures such as circulators, cavity filters, and digital filters could be used as funds become available.

It should be noted that the bracket and feedline are already in place at the 125-foot level, and are owned by the RMRA.  

 

Alternative Proposal:

  • Establish a second receive position on the west side of the tower. Since the antenna pattern nulling is most noticeable on the system receiver, a second receive only antenna could be mounted on the northwest leg bracket. This antenna would be connected to a new 146.22 MHz receiver. The output from this receiver and the existing receiver connected to the east leg transmit/receive antenna would be inputted to a voter. The better of the two signals would be fed to the transmitter. 

 

  • Establish a one or more satellite receive sites to the west of Rib Mountain.

 

Paul Nelles K9DB

4 Jan 2004

- end of proposal -

 

 

After discussion it was decided by consensus that even though the 146.22/.82 system probably does suffer some compromise in antenna pattern to the west, a reconstruction of the 146.04/.64 system on Rib Mountain would not be desirable. With the removal of .64 from Rib Mountain, it is believed that the 146.22 MHz receiver can be reequipped with its preamp and returned to near its maximum performance. K9DB’s proposal had assumed that interference from the .64 system was due entirely to the 146.64 MHz transmitter getting into the 1466.22 MHz receiver. However the problem was a result of a more complicated mix of frequencies including a harmonic of a strong 146.04 MHz transmission. The permanent solution may involve running a split antenna system using antennas at both levels. A single additional receiver on the west side of the tower and multiple remote receive sites remain as plausible solutions.

 

Tower crews are scheduled for commercial work later this week and may be available to reinstall the cross band coupler removed in October and re-enable the 444.3 MHz UHF system. The noise has not been present since the coupler was removed, and the coupler has been checked out on the workbench, leaving the coupler to antenna jumper as the likely source of the noise. This will be swapped out.

 

The immediate system engineering goals of the organization were prioritized. They are:

1.  Return the existing antenna system, both VHF and UHF, to fully functional.

2.  Installation of a second VHF antenna on the RMRA bracket at the 125-foot level.

 

The long-range system improvement goals as will appear in any capital improvement funds request were prioritized. They are:

1.  Replace the existing Spectrum Communications 146.82 MHz transmitter and power amplifier system with a newer or state-of-the-art transmitter package.

2.  Replace the obsolete ACC Controller system with a newer or state-of-the-art controller, preferably one that can accommodate multiple repeaters.

3.  Improve receiver coverage with multiple remote receiver sites

 

It was decided that any request for capital improvement funds should have these goals enumerated into this three-tiered plan.

 

New Wisconsin Section Emergency Coordinator Bill Niemuth KB9ENO has agreed to speak at the February quarterly meeting. However, the WVRA announced at the meeting Tuesday night that they were attempting to bring him in at about the same time. In order to avoid duplicate programs, it was decided that the RMRA should suggest a single jointly sponsored event. K9DB will contact Myron Oestreich KB9STB to coordinate.

Officers for the 2003-2004 fiscal year were chosen by consensus. They are:
President - Rich Maier KC9NW

Vice-President - Dean Andrewjeski K9PT

Secretary - Paul Nelles K9DB

Treasurer - Mike Martens KB9VBR

Member at Large - Bill Bergs KC9UC



Meeting adjourned 21:30.

Respectfully submitted,

Paul Nelles K9DB
Secretary