Information on the REPEATER SYSTEM


I own and operate a HAM (Amateur Radio) repeater system in South-central Dakota County, which is about 30 miles SSE of the Minneapolis-St. Paul, Minnesota area. The repeater is near Hampton, which is 30 miles South-East of the MSP metro area on highway 52; It can be heard on 147.360 Mhz, if you have a scanner, or a 2-meter FM radio.

This repeater has two independent, but PARALLEL COR (carrier operated squelch) circuits on board. As a result, one can access this repeater with a valid signal on the input of the repeater, no matter if the sub-audible tone of 136.5 Hz is present or not on a user's transmitter.

I have a spare (redundant) repeater, complete with all of the needed controllers, duplexer, antenna, etc. on hand. The alternate is sometimes pressed into service, if the one in service develops a small problem.

To use the repeater, set your transmitter to 147.360 Mhz, POSITIVE offset. If you would like the maximum range, set the transmitter to send 136.5 Hz, which will allow the repeater to have a LOT better receiver sensitivity.

It is an "open" repeater system for the active radio amateurs in this area, or for licensed hams who are simply traveling through this locale.

Here's a picture of the PRESENT antenna system for the repeater. I am presently employing two of the DB-224 antennas, using an ANTENNA SPECIALIST'S power divider to join the two. As you can see, I also have a redundant antenna for the repeater. (See the picture below.)


Echolink

This repeater system is equipped with EchoLink.  Read about Echolink here!   My repeater (on 147.360 Mhz output) has the Echolink node number 9636.  The Echolink "node" number of 9636 was chosen as my "repeater pair" is 96-36.  (147.96-36 Mhz.)

Echolink Frequently-Asked Questions here...   http://www.echolink.org/faq.htm 

    Sample questions: 

Is Echolink available for any platform other than Windows??

Echolink is designed specifically to run under Microsoft Windows.  Currently, there are no plans to offer versions of EchoLink for other platforms.

However, if you are running a Macintosh with OS X, you can use the program EchoMac by N9YTY, which is compatible with Echolink.   If you do, please first register here to begin the validation process.  (Support for EchoMac is not available through the Echolink Web site.)

What's the easiest way to test and adjust my audio?

There is a special "echo" conference server, called "ECHOTEST," to which you can connect to test your audio.  Once connected, the server simply records anything you transmit and plays it back.  This is a convenient way to verify that your transmitted audio is clean, and to adjust record and playback sound levels.  You can connect by choosing "Connect to Test Server" from the Station menu.  If you are connecting to EchoLink via an RF link, the node number for "ECHOTEST" is 9999. 

Here is some basic information on my system...

Command

Description

DTMF Code

Connect

Connects to a station on the internet, based on its node number. The node numbers can be 4, 5 or 6 digits.

nnnnnn

Random Node

Selects an available node (of any type) at random, tries to connect to it.

00

Random Link

Selects an available link or repeater (-L or -R) at random and tries to connect to it.

01

Random Conf

Selects a conference server at random and tries to connect to it..

02

Random User

Selects an available single-user station at random and tries to connect to it. .

03

Status

Announces the callsign of each station currently connected.

08

Reconnect

Reconnects to the station that was most recently disconnected.

09

Disconnect

Disconnects the station that is currently connected. If more than one station is connected, disconnects only the most-recently-connected station.

#

Play Information

Plays a brief ID message.

*


To establish a Echolink connection with your radio

  1. It is recommended that you first identify your station on the repeater and that you are attempting Echolink operation.
  2. Optionally, you can determine if the Echolink gateway is operational by keying a "*" DTMF tone. The gateway node will respond with status information.
  3. Type in the four, five or six digit station code for the station or repeater that you wish to link to.
  4. There is a special "echo" conference server, called "ECHOTEST," to which you can connect to test your audio and verify that your computer and its PORTS are properly set. Once connected, the "ECHOTEST" server simply records anything you transmit and plays it back when you stop transmitting.  This is a convenient way to verify that your transmitted audio is clean, and to adjust record and playback sound levels. (Always use this as an absolutely positive way to test your system's settings!)

    You can connect by choosing "Connect to Test Server" from the Station menu on your computer. You do NOT need to be connected to a node to run this audio test; In fact, if you are connected to any node, these will be disconnected if you connect to node number 9999.

    If you are connecting to EchoLink via an RF link, the node number for "ECHOTEST" is 9999. (Transmit "9999" when you are connected to any Echolink access point or node.)

     
      
    (Summary: -You can TEST your system by connecting to the "Test Server" at node number 9999.  -Enter "9999" on your radio's touch-tone pad, then follow the audio response information.  When the test server stops talking, TRANSMIT to the test server, then LISTEN to how you sound.  Test as much as you need.  Be sure to disconnect from the test server when you are finished.)
  5. To continue with the normal use of the Echolink system: After you have transmitted the 4, 5 or 6 DTMF link number, there will be a few seconds delay, the Echolink node will respond with a "Connected" message if the link was successful. If the link was not successful, key a "#" to disconnect the gateway node.
  6. Following a successful connection, announce your presence on the linked repeater by calling a short CQ, or by announcing your intentions in some other way of your choice.
  7. When you are in QSO on Echolink, there IS NO NEED to delay your response to the other party. You are clear to transmit as soon as you hear the repeater's courtesy beep. (Delaying will only slow down your conversation...) At the end of the QSO, disconnect the link by keying a "#" DTMF tone. The Echolink gateway will respond with confirmation that the link has been disconnected.

Accessing Echolink From Your Computer

Perform the following the access a Echolink station or repeater from your computer.

  1. Download and install the iLink user program from the Echolink web site.  Macintosh users can run EchoMac, which is described on the Echolink web site above.  EchoMac is available at  http://www.dogparksoftware.com/EchoMac.html  
  2. Verify that you have a microphone properly connected to your computer and the the microphone input volume level is properly adjusted. (See step 4 below.)
  3. Connect to the internet and run the Echolink or EchoMac user program.
  4. TEST your system by connecting to the "Test Server" at node number 9999.  (Enter "9999" in the "connect to" window, then follow the audio response information.  When it is your turn, TRANSMIT to the test server, then LISTEN to how you sound.  Disconnect from the test server when you are finished.)
  5. After you have adjusted your system, you may select a station or repeater to link to, from the displayed Echolink station link. (Double-click the station on the list to connect, as an example.) When you are in QSO on Echolink, there IS NO NEED to delay your response to the other party. You are clear to transmit as soon as you hear the repeater's courtesy beep. (Delaying will only slow down your conversation...) At the end of the QSO, disconnect the link by Selecting DISCONNECT from the program's menu. The Echolink gateway will respond with confirmation that the link has been disconnected.
  6. Once connected, use the Enter key or spacebar to toggle between transmit and receive.


Main Tower picture

Rural Minnesota! We grow REPEATERS, as well as corn...

(Click on the small image above to see the full size picture...)


The K0JTA tower was originally 140 feet tall. It was a self-supporting tower, manufactured by Rohn. It suffered storm damage, and is now just 40 feet tall. The tower's concrete footings are 11 feet deep. This tower (and secured structure) is the "home" of the 147.360 Mhz repeater system described below. [-For more info and pictures on both of these events, see the "damage pictures" link.]

The repeater system has a range of more than 30 miles, depending on the terrain, and the configuration of the mobile radio.  (Some mobiles have somewhat better range.)

The transmitter (TX) and receiver (RX) that make up the repeater are made by GE.  (Mastr IIe series.)  The repeater has a 75 watt transmitter.  I have the transmitter set to produce about 25 watts of RF power out of the duplexer at this time.  The repeater receiver has a GE Mastr II "preamp" to assist the reception.

In the summer of 2002, the repeater system was severely "kicked" by power-line sourced lightning damage.  As a result, I had to get a different radio (A Mastr IIe) and controller, and develop a new repeater system.  (I also had to add a new power supply, as the original was toasted...)

I made up a second repeater, as I like the redundancy this can offer.

The MAIN duplexer is a Sinclair 4-cavity unit. The SPARE duplexer is made by Wacom, and is a full-size duplexer.)


Above: The GE Mastr IIe, with NHRC controller and digital audio delay. To the right of the GE radio is the Sinclair duplexer. Above the duplexer is a dual RF power and SWR bridge unit. With this, I can monitor the repeater's RF power INTO the duplexer and also OUT of the duplexer. I can also check for any reflected power, etc.

Above: The location of the spare duplexer, which is made by Wacom. The "lightning box" is a home-made version of what is commercially available. It is made of stainless steel, and has the needed lightning arrestors and large (redundant) grounds. The "MAIN antenna feed-line" is just under 2 inches in diameter. The hard-lines to the main and the backup repeater antennas have a 50 foot run.

(Click on any of the small images above to see the full size picture, then use your BACK BUTTON to return to this page...)


The MAIN repeater antenna system is a DB Products DB-224E.  It is top-mounted on the tower, at the 40 foot level.  The antenna is about 24 feet long.  This antenna was put into service in September, 2003.  New "almost 2 inch" Heliax was installed for this antenna. This feedline is extraordinarily large!  (The connectors cost me $125.00 each!)  -Way too big!

The STANDBY antenna system is a Hustler 7 dB unit.  It is side-mounted on the tower, at about the 40 foot level.  This antenna was put into service in 2001.  The MAIN repeater antenna is presently being fed with two inch hard line.  This feedline for the spare repeater antenna is half-inch Heliax.

Below: Views from the crane, when the new DB-224E was installed at the top of the THEN 140 foot self-supporting Rohn tower. (from the TOP!) This tower was damaged, and is now only 40 feet tall.

Tower damage to 140 foot tower:
The top 100 feet on the self-supporting 140 foot tower was blown down on the evening of September 16, 2006! [-For more info and pictures on both of these events, see the
"damage pictures" link.]


Main Tower picture

Above: Looking down the boom.......

Main Tower picture

Above: The garden (and the crane, at the lower-right...)

Main Tower picture

Above: A second view of the business end of the crane.


Below: More views from the top..!

Main Tower picture

Above: The shadows.......

Main Tower picture

Above: Looking DOWN at the top of a 140 foot self-supporting tower!

 (We are about 15 feet above the tower at this time; -Resting, as we wait for the ground crew to secure the new antenna, and hoist it up to us.  The old UHF antenna is at the left on the ground, and the new DB Products antenna is at the right.


Main Tower picture

Above: My helper in the bucket is Mark, K0MDM


Main Tower picture

Above: Looking down on my THEN puny little 56 foot Rohn tower, at the left. -Turns out, this one is now the "big tower!"...