General Information
Technical
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click for larger image
This coverage map is based on a receiver antenna 6 feet above
ground, which is typical for mobile coverage. This is only an
estimate -- your "mileage" will vary.
LARK's primary repeater is the 146.85/25 MHz FM Repeater, well-known as "The 8-5". It's is open to ALL amateur radio operators. The 8-5 is used for all local SKYWARN and ARES activities, communications during community events, and the Northeast South Dakota Two-Meter Net (Tuesdays at 9:00 PM).
The 8-5 is located on a city water tank near Mellette School in Watertown. LARK shares this site with the Watertown Municipal Utilities. At 1795 feet above sea level, this is one of the highest points in town. The water tank adds 100 feet of additional elevation. The top of the tank can be seen from most parts of town. This is one of the best repeater sites in the area!
General Information
Technical
|
LARK's repeater radio and antenna were replaced on November 1st, 2003, and a CAT-1000 controller was installed on January 25th, 2004.
In October 2005, a new communications building was installed at the repeater site and new repeater equipment was installed for the Police and Fire Departments. We were also invited to move our equipment into the new building. Our move was completed October/November 2005. We have also received word that the city plans to tear down and reconstruct the water tank at the site. Because of this, we have decided to postpone the replacement of our feedline until the new water tank is in place.
The move to the new building required a few major changes to our repeater system. Our first concern was the flooded lead-acid batteries we use. While in a charging cycle, they emit some hydrogen gas. In the old repeater building this was never a problem because that building was "not exactly air-tight". This new building is supposed to be very tight, and vented hydrogen gas was a concern. A passive ventilation system was constructed to provide a sealed path for the gas to safely vent to the outside of the building. This system was constructed of 3/4" PVC pipe, 1" flexible tubing, lots of fittings, and Fernco adapters which just happen to fit the anti-explosive vent/funnel caps on our batteries.
Another concern that arose during the move was the possible overflow or spill of lead-acid from the batteries. It was decided to set the batteries in a plastic tray so that if there ever was spillage, it would hopefully not go any further than the tray (and hopefully not into anyone else's equipment).
The second major change was rackmounting the equipment. Plywood shelving was used to accomodate the equipment in the old building, but this new building just needed something more fancy and up-to-date. A standard 19" equipment rack was donated to LARK by KBØLCR's employer (DailyPost.com), and KBØRBG donated a 19" rackmount shelf. The CAT-1000 controller was already rack-mountable. The duplexers were adapted to fit the rack using two pieces of 1" square perforated steel tubing. Finally, WBØWIH constructed an aluminum bracket to hold the battery voltmeter. This made for a neat, professional-looking installation.
A Polyphaser ligting arrestor was also installed into the feedline.
In May 2010, Watertown Municipal Utilities began a project to replace the aging water tank with a new state-of-the-art water tower. They estimate that this project will take about one year. During the construction, they have installed a wooden pole at the same site and mounted a temporary antenna for us at 55' above ground. This somewhat limits our "normal" coverage, but is still very usable. We estimate to have the repeater back to normal working condition sometime during Summer 2011.
See the pictures below documenting changes made!
 9/18/2015 Jumper replaced o... |
 9/18/2015 Jumper replaced o... |
 9/18/2015 View to the South... |
 9/18/2015 View to the South |
 9/18/2015 View to the South... |
 9/18/2015 View to the North |
 9/18/2015 View of Prairie L... |
 9/18/2015 View to the West |
 9/18/2015 Installing N-conn... |
 2/22/2013 KB0LCR standing n... |
 2/22/2013 KB0KBJ talking to... |
 2/22/2013 The view up into ... |
 5/10/2012 New Water Tower -... |
 5/10/2012 New Water Tower -... |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower -... |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower |
 5/10/2012 New Water Tower -... |
 5/18/2010 9:00 AM - Tempora... |
 5/18/2010 Getting ready to ... |
 5/18/2010 Changing drill bits |
 5/18/2010 Here's our tempor... |
 5/18/2010 Drilling the firs... |
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 5/18/2010 Installing the Fi... |
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 5/18/2010 Antennas are read... |
 5/18/2010 2:30 PM - They de... |
 5/18/2010 3:30 PM - Finally... |
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 5/18/2010 Hooking up to the... |
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 5/18/2010 Huge crane! |
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 5/18/2010 Starting to raise... |
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 5/18/2010 This branch was i... |
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 5/18/2010 Up, Up, and Away! |
 5/18/2010 About here, the p... |
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 5/18/2010 The pole's up, no... |
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 5/18/2010 They make this lo... |
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 5/18/2010 Finally made it i... |
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 5/18/2010 Now, to unhook th... |
 5/18/2010 The crane made se... |
 5/18/2010 Leveling the pole... |
 5/18/2010 4:30 PM - It's re... |
 5/19/2010 Repeater antenna ... |
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 5/19/2010 Antenna and feedl... |
 5/19/2010 Feedline run from... |
 5/19/2010 A view up the pol... |
 The 146.850 Repeater as of ... |
 Inside the shack before we ... |
 Watertown PD and FD Repeaters |
 Grounding system |
 Grounding system |
 Entrances for the coax. The... |
 Feedlines between the shack... |
 The abandoned 1/2" feedline |
 Here we were testing the ab... |
 Testing the feedline |
 Testing the feedline |
 This picture shows the trip... |
 Testing the feedline |
 Testing the feedline |
 Testing the feedline |
 Testing the feedline |
 Testing the feedline |
 Testing the feedline |
 Still testing... |
 Another view. Here you can ... |
 Testing the feedline |
 Testing the feedline |
 Testing the feedline |
 View facing south. It was a... |
 View to the southeast. |
 View to the southwest. You ... |
 View to the west |
 View to the east (slightly ... |
 I think this is Watertown H... |
 View to the north |
 View to the north, zoomed i... |
 Spying on the sheriff's hou... |
 Spying on the sheriff's house |
 Directly south |
 KB0LCR chatting with the ne... |
 KB0LCR chatting with the ne... |
 Closeup of the UHF antenna ... |
 Closeup of the UHF antenna ... |
 Closeup of the UHF antenna ... |
 Connected to the abandoned ... |
 Looking "down the barrel" o... |
 UHF antenna, pointed southwest |
 UHF antenna, pointed southwest |
 UHF antenna, pointed southwest |
 View to the south |
 No idea which direction thi... |
 View to the southeast |
 Not sure which direction, m... |
 View of downtown Watertown |
 I think this is a view to t... |
 The completed antenna project |
 10/26/2005: Homebrew batter... |
 10/26/2005: Battery tray co... |
 10/26/2005: Homebrew vent a... |
 10/26/2005: Partially assem... |
 10/26/2005: Fully assembled... |
 10/26/2005: KBØLCR wiring ... |
 10/26/2005: Aren't racks cool! |
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 10/26/2005: Rear view of ra... |
 10/26/2005: More wiring |
 10/26/2005: Assembling an N... |
 10/26/2005: WBØWIH and KFÃ... |
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 10/26/2005: WBØWIH and KFÃ... |
 10/26/2005: Getting closer ... |
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 10/26/2005: Sizing up a she... |
 10/26/2005: Break time! |
 10/26/2005: Batteries are a... |
 10/26/2005: Cutting tubing ... |
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 10/26/2005: Topping off the... |
 10/26/2005: Batteries vente... |
 10/26/2005: Doesn't that lo... |
 10/27/2005: Looks like the ... |
 10/27/2005: Yesterday we di... |
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 10/27/2005: Another view of... |
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 10/27/2005: Rear view of th... |
 10/27/2005: Polyphaser Ligh... |
 10/27/2005: The old EMS and... |
 10/27/2005: Here's the old ... |
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 10/27/2005: Bugs were makin... |
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 11/01/2005: Generator room |
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 6/12/2004 View from the top... |
 Kurt NØVEK stands proudly ... |
 Medivac helicopter coming i... |
 Repeater's vacation site. K... |
 Repeater's vacation site. K... |
 Closeup of the final amplif... |
 Inside the repeater while i... |
 Picture of the water tower ... |
 The shack that houses the 8... |
 11/1/2003 Loading up the tr... |
 11/1/2003 Picture of the wa... |
 11/1/2003 View of the groun... |
 11/1/2003 Jeff (KØJLR) and... |
 11/1/2003 Climbing crew bef... |
 11/1/2003 Climbers going up... |
 11/1/2003 Climbers going up... |
 11/1/2003 View up the ladde... |
 11/1/2003 Climbers on top o... |
 11/1/2003 Close up of the n... |
 11/1/2003 Ground crew is re... |
 11/1/2003 This 500' rope wa... |
 11/1/2003 The rope |
 11/1/2003 Before the antenn... |
 11/1/2003 Installing the mo... |
 11/1/2003 The new antenna g... |
 11/1/2003 Tony pulling the ... |
 11/1/2003 The old quad J-po... |
 11/1/2003 The old antenna c... |
 11/1/2003 Everyone was curi... |
 11/1/2003 Warming up in the... |
 11/1/2003 Dave (NØDL), Val... |
 11/1/2003 Mounting the new ... |
 11/1/2003 Mounting the new ... |
 11/1/2003 Inside the shack.... |
 11/1/2003 We share this tow... |
 11/1/2003 Tony (KØTY) comi... |
 11/1/2003 Coming back down ... |
 11/1/2003 Winding the rope ... |
 11/1/2003 Everyone's happy ... |
 11/1/2003 The Climbers afte... |
 11/1/2003 Everything's done... |
 11/1/2003 Warming up in the... |
 1/25/2004 CAT-1000 controll... |
 1/25/2004 CAT-1000 controll... |
 1/25/2004 CAT-1000 controll... |
 This is an old picture of t... |
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 Old picture of the shack th... |
11/01/2003 • New repeater and antenna installed. Vertex VXR-7000 and Hustler HX6-14448. Gary (WØGC SK), Kurt (NØVEK), and Tony (KØTY), climbed the water tank to remove the old 4 Bay Inverted J-Pole antenna and install the new Hustler antenna.
01/25/2004 • CAT-1000 Repeater Controller installed and put online.
03/24/2004 • Repeater apparently experiencing some technical difficulties. Stations within a few miles can copy the repeater but with considerable hashing. Stations outside of Watertown cannot copy the repeater at all. Kevin (KBØLCR) and Denny (KFØHL) made arrangements to inspect the repeater. A watt/SWR meter was installed inline with the antenna, and it was found that the repeater would start up with full power for a second or less, then drop to very low output (below 1 watt). The antenna showed an SWR just above 2:1. It was concluded that the problem had to be in the repeater itself. Unfortunately, Jim (WØMJY) and David Smith (KAØJDN) from Burghardt Amateur Center were both out of town, and since the repeater is new and still under warranty, it was decided to wait for them to return before dealing with the problem.
03/29/2004 • KBØLCR and KFØHL delivered the repeater to Burghardt Amateur Center. Output from the transmitter could not be measured with an RF wattmeter, but could be seen on a service monitor. Upon visual inspection it was found that an output capacitor on the final amplifier board had failed and probably caused something to short to ground, which was why there was little or no output. A new amplifier board was ordered overnight.
03/30/2004 • The new final output board was installed and repeater was put back on the air.
04/01/2004 • Repeater transmitter has failed again. It appears that there are problems with the antenna/feedline system causing a high SWR. Plans are being made to send climbers back up the water tower to inspect and fix whatever needs it. In the meantime, the repeater is temporarily off the air.
04/13/2004 • Repeater downtime is approaching two weeks, so it was decided to temporarily put the repeater on the air at KBØLCR's home QTH. The repeater, controller, receive filter, and duplexers were moved from the repeater site to four miles southwest of Watertown, just south of Lake Pelican. Click Here for a map to the repeater's vacation location. It is currently connected to a Cushcraft dualband antenna up about 54 feet. Although the range is noticeably limited, it's better than no repeater at all. Mobile coverage seems to be good.
05/03/2004 • During a technical committee meeting on 5/1, Tony (KØTY) offered to let LARK temporarily put the 146.850 repeater at his business location and connect it to his antenna. The antenna is a Diamond dualband at approximately 108' above ground, on a ROHN 25G tower. The antenna is fed with 7/8" heliax. After some discussion, the technical committee agreed that this would provide better coverage than the repeater's current location. The repeater was moved from KBØLCR's home QTH to KØTY's tower.
05/30/2004 • At about 1:00 PM during a severe thunderstorm, ligtning struck KØTY's antenna, completely destroying it. Thanks to his grounding system, the repeater was not harmed. Unfortunately this means the repeater will need to be moved again (and that KØTY is out an antenna). The repeater will be temporarily off the air until a solution can be reached.
06/12/2004 • Houston, We're Go! After months of repeater troubles, several vacations, and taking one lightning strike, the 146.850 repeater is finally back at home and working properly. Thanks to Kurt NØVEK and Rob NØTAW from the Deuel County Amateur Radio Club, a new temporary feedline was installed on the '85 repeater antenna. Jim Smith WØMJY of Burghardt Amateur Center loaned us about 140' of Times Microwave LMR-400 Ultraflex to temporarily replace the 7/8" heliax that has apparently gone bad. Eventually a new run of 7/8" heliax will be installed, but that action is pending some other operations. Anyway, the repeater is BACK ON THE AIR for "Regular Amateur Abuse".
02/11/2005 • Repeater is receiving and retransmitting interference with a "squealing" sound. After a site inspection, it was determined that Midcontinent Communications has a cable leak somewhere within the vicinity of the repeater site (Probably at Mellette School). KBØLCR spoke with Bob Spilde of Midco in Watertown, and one of their RF techs also reported hearing a leak in the area on the detector in his truck. Bob indicated they would be up shortly to fix it, which they eventually did. (exact date unknown)
08/02/2005 • Several operators have reported that the range of the repeater appears to be limited, on receive and transmit. This was especially noticeable during the NESD Two-Meter Net.
08/03/2005 • Clark (KBØRBG), Denny (KFØHL), and Kevin (KBØLCR) inspected the repeater and found that it was transmitting in a low-power state (approx. 1/2 watt, compared to the usual 50 watts). Antenna checked out good (about 1.3:1 SWR). After loosening and re-tightening all connections, repeater came up as normal. It is also worth noting that it was VERY hot in the repeater room when the door was opened, primarily due to the hot weather and the fact that the room is not vented.
08/04/2005 • It was again noted that the repeater is transmitting in a low-power state. It was discussed that the repeater's final output transistors may be shutting off due to the temperature of the room and/or the repeater itself.
08/09/2005 • Upon closer inspection of schematics and documentation, it was determined that the repeater is not entering the power-down state due to heat, but that it must be malfunctioning (possibly bad solder connection or failing final output transistors). It was decided that the repeater will be returned to Burghardt's for repair.
08/10/2005 • 9:00am. Repeater removed from service to be repaired at Burghardt's.
08/10/2005 • 5:00pm. David from Burghardt's couldn't replicate the problem with the repeater at the shop so he asked to check things at the site. He was met by Kevin (KBØLCR) and Denny (KFØHL) at the site and the repeater was reconnected to the duplexers with a dummy load and power meter. After several seconds of transmitting, power output at the antenna-side of the duplexers dropped again, but power output from the repeater was full-power. It was then determined that the problem was not in the repeater but in the duplexer. David took the repeater, controller, duplexer, and all coax jumpers back to the shop for more testing.
08/11/2005 • 8:30pm. Repeater trouble has been resolved. A loose connection was found in one of the duplexer cans. David was able to successfully repair the duplexer and the repeater is back on the air for normal operation. David also replaced all jumpers in-between duplexer cavities and to the repeater.
10/25/2005 • Work has begun on moving repeater into new communications building.
10/26/2005 • Repeater move completed, still need to connect batteries and do some post-move tasks
11/01/2005 • Move completed. Repeater is now 100% operational in city's new communications bulding.
05/18/2010 • Began antenna move to temporary 55' wooden pole, in preparation for replacement of water tank.
05/19/2010 • Move completed to temporary tower.
02/22/2013 • Repeater finally repaired after a long outage. Now located on new tower, full power
09/18/2015 • Jumpers from duplexer to lightning protection, lightning protection to feedline, and feedline to antenna, all replaced with RG-214 (were previously LMR-400). It was suspected this was causing some receive trouble to the repeater.