The South Dakota Amateur Radio Council (SDARC) owns and operates the SD-Link. SDARC is registered as a non-profit corporation in the State of South Dakota under SDCL 47-22. SDARC also has 501(C) (3) status under the Internal Revenue Code and is treated as a public charity. Contributions to SDARC are charitable tax deductions. SDARC participates in civic and educational activities. Civic public service activities will be providing emergency communications and back up emergency communicatations for FEMA, state, county and local law enforcement agencies. state and county Emergency Management and civic organizations such as the American Red Cross. The corporation will participate in a number of other civic activities such as providing various communications services for public service organizations.
Educational activities will be to train amateur radio operators and clubs to be able to effectively provide emergency and backup communications for the groups mentioned above as well as other groups. Training will also be provided regarding technical operations that make these communications possible and reliable in times of disaster. The corporation will participate in other educational activities such as informing the public how to use the volunteer communications services of amateur radio operators during times of disaster,
The corporation also strives to provide activities that will promote cooperation and brotherhood among those amateur radio operatiors providing services to meet the civic and eduational purposes of the corporation. The corporation works with the American Radio Relay League (ARRL) with its Amatuer Radio Emergency Service and Dakota Amatuer Radio Network (DARN) and it memorandium of Understanding (MOU) with the state of South Dakota.

SDARC has meetings from time to time to gather input in regards to its activities. It also gathers input through a weekly Wednesday night net on the SD-Link at 8 pm Mountain and 9 pm Central time and a Yahoo group http://groups.yahoo.com/group/sdlink/ and a web site www.sdlink.org. SDARC has a SD Link Repeater committee that consists of SD Amateur Radio Club representatives and individuals interested in the successful operation of the SD Link system.

Please consider making a donation to support the link. The SDARC is a 501c3 organization and all donations are tax-deductible. Donations of equipment are also accepted and will be sold at various hamfest events throughout the state for the benefit of the link.

Contact Ed at his address below or make a donation through PAYPAL.

Ed Gray W0SD Treasurer
43804 257th Street
Salem, SD 57058

SDARC Board of Directors
AA0F Don Schwemle President
N0LCL Brian Kelly Vice President
W0SD Ed Gray Secretary Treasure
KD0S Jim Zahradnicek

Early SD-Link History(1991-2003)
The first part of the SD-Link went on the air in October of 1991 and is considered our anniversary date. There is no question about it. The founding fathers of the SD Link System are AA0F-Don Schwemle and N0LCL-Brian Kelly. The SDARC was incorporated as a non-profit corporation under South Dakota law on September 8, 1994. The first officers were and are President AA0F-Don Schwemle, Vice President N0LCL-Brian Kelly and Secretary/Treasure W0SD-Ed Gray. The first sites were at Humboldt and Wessington Springs.
An early donation to the SD-Link of several repeaters was made by Bob Ewing-N0YOL from Rapid City.
Dates that repeaters went on the air are.
285 went on 5-11-91
345 went on 8-3-91
940 went on 7-20-94
300 went on 7-20-95
730 went on 7-21-95
375 went on 7-22-95
030 went on 1-27-96
Humboldt was on the air first in 1991 (Darrel KB0AWB secured the agreement to get on the original site). Wessington Springs went on the air about 3 months later in 1991 and they were initially operated without linking. A short period later the two sites were linked using purchased controllers. We were not pleased with the performance or features of the linking features of the controllers, and by the time that we considered adding Turkey Ridge to the system which had been stand alone for quite some time. We realized that a better linking system would be needed. After reviewing commercially available linking controllers, we decided to design and construct our own. Dave Mattox, WB0JEK, provided extensive circuit design and printed circuit board layout for the Motorola (68HC05) microprocessor based system. Don, AA0F, wrote the majority of the firmware for the controllers, and Brian, N0LCL provided his expertise in integrating it into a working system. The first prototype SDLINK controller was initially installed at Turkey Ridge, and after some hardware and firmware revisions, controllers were constructed for the Humboldt and Wessington Springs sites. When the newly constructed Garden City repeater was added to the system, it was also configured with a similar controller, as was the Reliance repeater when it was adapted to the linked system (don’t know what year this was done)..
Turkey Ridge was put on the air through ground work by Ed Gray W0SD in conjunction with the Mitchell ARC and Prairie Dog ARC. Permission for the site was given by WA0QLP on his land where a nearly 200 foot tower was installed. It was not long until the responsibility for this site was completely taken over by the PDARC which continued until 2008. The PDARC with lots of building material donations from Del K0GDS (silent Key) built a repeater housing structure at the base of the tower The Garden City(Garden City Repeater Corporation) and Reliance(Medicine Butte ARC)which had been stand alone for a long time were soon added to the SD Link.
Work was then done by SDARC to secure a FEMA grant to expand the Link to Pierre, Murdo, Philip, Terry Peak and Rapid City. Don Herrick Davison County Civil Defense Director was the primary force in securing the $67,200 grant. The sponsor was the SD Division of Emergency Management in conjunction with the Division of Emergency Services. The goal of the proposal was to complete amateur repeater coverage along the interstate system and the major population centers in South Dakota.
When the expansion of the system was done to include Murdo, Pierre, Philip, and Terry Peak, the controllers were upgraded to use a new microprocessor (Motorola 68HC11 based), and the firmware was ported to the new hardware and a new C compiler.
A big thank you for countless help from many amateurs at the various sites who constructed and install repeater buildings, did site preparation, served as tower crews, did antenna mount fabrication and many other things.

2004-2008 Period
In 2004 a group of interested amateurs met at Chamberlain SD with the goal of getting the total SD Link working again. In 2003 and 2004 some of the link was in dis-repair. As a result of this meeting a good deal of work occurred to restore the link. In April 2005 a meeting was held in Sioux Falls to continue to facilitate the work to restore and develop plans for the long term continuation of the successful operation of the South Dakota Link. Links to the minutes of these meeting can be found immediately below. WB6GHA John(now silent key), KG0R, KD0S and W0SD were major players in this effort. The SDLink restoration was completed during the summer of 2005.
With the SDLink being operational again from end to end in 2005 some problems surfaced. One major one was a double courtesy beep. Through some hard work by KG0R, WB6GHA, AA0F and W0SD this problem was solved. During 2006, 2007 and 2008 the SDLink worked from end to end with some issues and down time at some locations from time to time. In 2008 KG0R, W0SD, WA1RJC and AA0F began a major update of the UHF link equipment. Unfortunately Howard KG0R moved to TN in September of 2008 with his job but before he left he made major contributions on building several new SDLink controllers and preparing new UHF link radios for Turkey Ridge and Pierre. Also during 2007 and 2008 KD0S and WA1RJC spent a lot of time and effort keeping things running at the western sites. KG0R, AA0F and W0SD with some help from Brian N0LCL kept things running in eastern part of the system. In September 2006 the Humboldt site had to be moved. A new free site was provided by Vantek owned by LeMar W0VH. This site definitely has better coverage than the old site. In late 2007 Al-N0OII became a silent key. Over the years Al provided a lot of equipment donations to the SDARC and will be missed. In 2004 the SDARC web site was started.
2007-2009 In More Detail

WB0RJH Greg of Pierre started the SDLink Wednesday night net. This net meets every Wednesday night at 9:00 pm Central or 8:00 pm Mountain time. SDARC is always looking for Net Control Stations so please volunteer to do so. You may contact WB0RJH, KD0S or W0SD on the net and let us know you would like to be a NCS. Dale-WA1RJC has set up a link between the Black Hills Repeaters and the SDLink. This link is used each Wednesday evening during the SDLink net making check-ins possible from WY and NE and all over the Black Hills area. The SDLink net on the eastern end of the state also makes check-ins possible from MN, NE and IA so 5 states can be represented on the SDLink net.
The SD-Link Yahoo group was started in May of 2005. The URL is http://groups.yahoo.com/group/sdlink/
During 2007 the Dakota Amateur Radio Network(DARN) signed an memorandum of agreement with the State of SD to work with the state agencies in providing emergency communications. The SDLink will be a major component of the SD Amatuers emergency communications services since the SDLink has battery back up at its sites and coveres such a large portion of the state. The Black Hills Area repeaters can also be linked in and on a demand basis the GLARA (Northern SD Link) should be able to be tied in.
During the late summer of 2008 major planning meetings were held by AA0F, WA1RJC and W0SD as to how to update the UHF link. During the fall of 2008 AA0F, WA1RJC and W0SD prepared new IC-F221S radio’s and new Kenwood TKR-850?s and MSF-5000?s to replace all the UHF equipment in the SDLink. This equipment was then installed in September, October and November of 2008 by KD0S, WA1RJC, AA0F, WA1RJC, N0ARU and W0SD. The new equipment for Terry Peak was installed in the spring of 2009.
The SD-Link moved into a new building at Pierre with an autostart propane generator. This building is at the same site at Pierre on Rattlesnake Butte. Also In 2010 the SD-Link Monitoring team was started and emergency drills were held on the SD-Link. A new sd-link website went on line at www.sdlink.org.
Seven new Kenwood TKR-750 2 meter commercial repeaters were purchased and installed at Humboldt, Wessington Springs, Garden City, Reliance, Murdo, Philip, and Terry Peak. These replaced commercial repeaters that were manufactured in the 1970’s, had served us well, but were due for upgrades.
SDARC purchased and installed two new Kenwood TKR-850 UHF repeaters at Terry Peak and Turkey Ridge.
SDARC purchased and installed large AGM type station battery systems at Turkey Ridge, Humboldt, Wessington Springs, Garden City, Reliance, Murdo, Philip, and Terry Peak. The weight of the battery bank at each site averages well over 2000 pounds with over 1000 amp-hours of storage, and dramatically extends each site’s ability to continue operation during power failure.
SDARC purchased a new repeater site (building and tower) at Wessington Springs and have moved that repeater system to the new site.
This was a huge effort, and SDARC thank all those (to many to individually list) for their help, whether it was moving batteries, recharging batteries where power was lost, working as tower climbers, or as ground crew, or doing repeater assembly or alignment. We had in excess of 28 “work days” with an average of at least 3 people at each session. This equates to in excess of 90 man-days or 700 man-hours of donated labor! A huge thanks to all of you!!
2012 SDARC Board of Directors:
AA0F Don Schwemle President
N0LCL Brian Kelly Vice President
W0SD Ed Gray Secretary Treasure
KD0S Jim Zahradnicek
In October of 2012 it will be the 21 aniversary of the SD-Link being in operation. The SDARC wants to thank all those who have contributed time, money and work to make this possible.
The land that the previous Turkey RIdge site was located on was sold the fall of 2011 and SDARC had to re-locate to a new site, and as a result had to re-configure the repeater to the 440 MHz band, and that repeater is operating, as of late April 2012, on 444.975 MHz, positive offset, and with a tone of 146.2 Hz.
Due to catastrophic feed-line failure, we lost the use of the Garden City repeater the spring of 2012. As a result, the SD-Link no longer had coverage to Aberdeen, to Watertown, or to surrounding regions. One of the long-term goals of the council has been to provide as much coverage as feasible to the Interstate highway corridors and to the major populations centers of the state, and the loss of Garden City immediately prompted us to try to find replacement locations to restore the coverage areas lost.
As a result of that effort, the South Dakota Amateur Radio Council Board of Directors announced a multi-site expansion effort to restore and improve our SD-Link system.
SDARC negotiated a new site for Turkey Ridge, and have reconfigured a new UHF repeater and completed installation at the new site on April 28th 2012
SDARC purchased a tower site near Toronto, SD, with the intent of adding a new 146.775 MHz repeater at that location and linking it down to the Humboldt UHF hub repeater with a new link radio. This site will provide improved coverage along I-29 and into such cities as Brookings and Clear Lake, but will additionally give us a new “path” to link back into the Watertown area.
SDARC announced they were working with individuals / clubs in the Watertown area with the intent to provide a UHF repeater in Watertown that will be linked to from the new Toronto site. SDARC anticipates much improved base station and mobile coverage in Watertown with this system.
SDARC obtained use of a tower site on the Crandall Hills southeast of Aberdeen. The intent was to operate the 146.67 repeater at that site along with new UHF equipment to link the site back to the Wessington Springs SDLink hub. The primary focus of this repeater will be to restore SD-Link repeater access to Aberdeen as well as provide coverage to portions of Highway 12 and cover a major portion of the James River Valley south of Aberdeen, including along Highways 37 and 281 south-wards to overlap with coverage from Wessington Springs.
The Crandall Hill repeater went on the air on May 12, 2012 and was moved to 146.79.
The Toronto repeater went on the air on June 15, 2012 on 146.775.
The Watertown UHF repeater at Prairie Lakes Hospital went on the air on June 28, 2012 and the frequency was changed to 442.000+ due to interference issues on the original frequency.

The Philip Repeater site was moved about quarter mile on September 30th 2012.  The repeater antenna height is about 150 feet and runs 25 watts.  The link radios use beam antennas.  It is about 3 miles SW or Philip.

2013: In the spring the Hub at Humboldt was upgraded to the TKR-850 and Motorola PA and the link going east from Wessington Springs to Humboldt was upgraded to a TKR-850 and Motorola PA.  In 2014 the VHF duplexers at Wessington Springs and Humboldt were updated to the Wacom duplexers we use at the other sites.

2014: There were no major changes in 2014 other than some maintenance projects.  We continued with our 12 sites.

2015: Unfortunately the tower at our Murdo site came down in June due to high winds.  We were able to put up a temporary tower in cooperation with Vantek before winter set in to get the UHF link working well going into the winter. We changed the UHF link radios from Icom mobiles to TKR-850s at Reliance.  Murdo was on the air on the UHF hub over the winter. SDARC also moved in the building that was previously at Philip to the site at Murdo.  Vantek secured a long term lease at Murdo so that site should be solid.

A lot of work was done early in 2015 on de-sense.  It was determined that the TKR-750 have more wide band noise than the Micor’s had so we found using a band pass filter on the TX got rid of the de-sense and permitted us to use pre-amps.

In the fall of we installed a remote Elecraft K3 at the WS site along with a 2 meter yagi and ran some test with Pierre and Rapid City.  Having a 2 meter SSB back up and addition to the SD-Link to get into Pierre and across the state from WS to Rapid City looks promising.

2016: In March 2016, work resumed on the Murdo repeater. The 100 foot Rohn #45  tower was completed and the UHF antenna installed. The UHF antenna is fed with 7/8″ heliax and placed on the north side of the tower at about 80 feet. We got the VHF portion of the repeater on the air on July 9th.  That antenna is on the south side of the tower.

2017-2019  SDARC has been working on adding a remote station at the Wessington Springs 147.345 site for some time.SDARC has had a users group since 2005.  The group now uses sdlink@groups.io  There is also the SDARCSDremote@groups.io. SDARC has had a web page for years.  The current web page is www.sdlink.org

The latest SDARC project is the remote station at Wessington Springs at the 147.345 repeater site which is owed by SDARC. The project started in 2015 with a K3 and solid state brick and a M2 2M beam mounted at about 100 foot on the 300 foot tower.  The beam was fixed west aimed between Pierre and Rapid City.  Due to falling ice from the tall tower the antenna’s had to be moved to a 50 foot Rohn #55 tower NW of the big tower to get away from the falling ice.

In the spring of 2019 a very severe ice storm and 50 mph + wind destroyed all the antenna’s and bent the mast on the Rohn # 55 tower at the remote. This past Friday the remote antenna system at WS has been completely rebuilt thanks to a very dedicated few. The antenna’s are a Mosley WARC beam, M2 rotor, stacked M2 2M beams, 80 dipole and 40 dipole.  The 2M remote can also operate on FM with a vertically polarized beam at about 20 feet with a Tail Twister rotor.

The equipment at the remote is a K3S, KAT500 Tuner, KPA-500 amplifier and M2 2M beam.  SDARC has a 2M net every Sunday night at 8:30pm Central time on Sunday night on 144.270 USB.

The access is via Remote Hams and equipment designed and supplemental software written by AA0F.  With the upcoming ARRL Simulated Emergency Test (SET) on Saturday October 5th the purpose of this e-mail is to explain the benefits of the SDARC SD-Link and Remote for emergency communication.  It is planned that eventually the remote system can function during emergencies without the Internet by using a UHF remote base at WS.  Presently it could be manned at the site by operators and the Internet would not be needed.  It operates on a large battery bank.

The SD-Link pretty well covers the state.  It consists of 12 sites.  All sites are on emergency battery power charged from the mains.  It does not use the Internet and it does not need telephones, etc.  It is completely stand alone.  Because it uses 2M and UHF links it is not effected by QRN or solar storms or QRM. One of the big advantages for emergency use is that there are always stations monitoring.

The SDARC remote has now proven with stations participating in the SDARC 2M Sunday night net and virtually being used every night that it can reliably cover all of east river SD to 100 watt stations.  It has also been proven that it is reliable to Rapid City(RC) to 100 watt stations(presently 5 and a station from Custer).  There is a remote on Radar Hill at RC.  Since this system requires only the WS Remote and home stations or EM stations, etc to cover the state it is much simpler than the 12 sites we have on the SD-Link.  It also would provide for a number of frequencies to be use where the SD-Link is basically everyone on the same “channel”.  These two systems supplement each other and also serve as a back up for each other.

The other huge advantage of the SDARC Remote is the FM capabilities it has where we can work virtually all the repeaters in eastern SD in addition to those on the SD-Link.  This gives us access to many amateurs in SD with mobiles and HT’s, in other words lots of “boots” on the ground.

As we move forward amateurs in SD are encouraged to add 2M SSB/digital capabilities to their stations to communicate with the SDARC remote.  Presently we have 2M SSB/digital stations in Aberdeen, Brookings, Sioux Falls, Yankton, Vermillion, Pierre, Huron, Redfield, Mitchell, Parker, Salem, Rapid CIty, Black Hawk and other smaller towns.  Of major towns we are only missing Watertown.  We also  have several stations who can operate portable throughout the state of SD.  We also have stations active in the surrounding states.

Amateurs in SD are asked to be sure amateurs in their area and through there local clubs are made aware of the SDARC remote station.  Again you are encouraged to have amateurs on 2m SSB/Digital with a beam and 100 watts in your area.  There is no charge to use the SDARC Remote as it is supported by ham volunteer work and donations.  To use the remote one needs to contact SDARC so one can get set up to do so.

In 2019 the Philip Site equipment was purchased by SDARC.  A yearly lease agreement for the site was made with the land owner.
2020 A big supported and worker on the SD-Link W0CB Ed Potzler became a SK because of Covid 19.

2021 On November 25, 2021 Rapid City UHF went on the air spearheaded by Mike KE0QIB.  The repeater uses the same frequency as it did before. 444.750 +5.00 with a tone of 146.2. It is located at the BHARC clubhouse on Radar Hill just east of Rapid City. We will still continue to have the Black Hills repeaters connect as they do now for the Wednesday net so when in Rapid City you can use either the new UHF or the VHF to check into the net.  The Rapid City UHF is on the SD-Link 24/7 so now all the major towns in SD are on the SD-Link full time.

2022 On April 30th the SD-Link at Humboldt was removed and the site was lost.  The tower was dropped on May 6th.  This meant Watertown, Toronto, SF-UHF and Turkey RIdge all of which used Humboldt to connect to the sdlink lost that connection.

SDARC decided to move the UHF hub that was at Humboldt to W0SD. The frequencies and tone will be that same as they were for Humboldt.

SF-UHF, Turkey Ridge and WS East bound link are now using the W0SD hub so the SF-UHF and Turkey Ridge are back on the SD-Link as of about noon yesterday, Tuesday May 3rd. This will be permanent and over time we will get a higher and better UHF antenna for the hub at W0SD.

On May 5th the SF-UHF link beam antenna was re-aimed from Humboldt over to W0SD.  The corner reflector at WS to the W0SD hub is pretty much right on with little difference in the heading to Humboldt vs. W0SD, ie 8 degrees at the most and the corner reflector is very broad.

To use the SD-Link traveling between Mitchell and Sioux Falls with 147.285 being gone you should use the W0SD hub which is a UHF repeater. You should set your radio for 442.075+ with a tone of 103.5. There is no courtesy beep and a long tail on all the SDARC hubs so you should pause a bit on over’s to prevent doubling but you don’t need to wait for the hub tail to drop as it is about 10 seconds long. Based on tests we have ran use SF-UHF around SF. Outside the SF area once you get west of SF past Hartford use the W0SD Hub until Alexandria SD and then switch to WS 147.345.

We are working on getting a new repeater in the Colman/Wentwoth area to link Toronto-Watertown into the SD-Link again and give us I-29 coverage north of SF and over into MN.

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