W4RFR/R 145.11 Repeater Operations



The W4RFR/R repeater is the primary repeater of The Henry Savage Ham Radio Club. It is a GE Mastr II repeater and an SCom 7K repeater controller. It operates on 145.11MHz with a -600KHz offset (Tx on 145.11MHz and Rx on 144.51MHz). It has a 151.4Hz PL tone. It is located on top of the 3322 West End Avenue building in West Nashville, TN, USA about 120AGL (Above Ground Level). It is also Echolink enabled and is node number 237900 under W4RFR/R.

This section of the site contains all of the information that we have collected over the years that we have been maintaining the repeater. Scott Smith (KF4ZIS-Nashville, TN) and Steve Mook (AD5TF-Round Rock, TX) are control operators of the repeater and are responsible for it's maintenance and connection to the Internet.

Please Note: Many of the documents on this site may have been modified specifically for the W4RFR/R hardware and software. For example, the Maintenance/Service Manual here was written for several different versions of the GE Mastr II repeater, so we have attempted to focus these documents on just the hardware that we have. No pages have been removed but we have reformatted several pages that we specifically needed in order that they would print better for us.

If you find anything that is out of date or incorrect on this site, please Contact Us with updated information. Any help is greatly appreciated.

W4RFR/R GE Mastr II Repeater
GE Mastr II Service/Maintenance Manual (6.93MB)
This is a very valuable document. It was written with reference to using a GE Test Set model 4EX3A11 or 4EX8K12. These are handy because they have 9-pin plugs on them that plug into several 9-pin diagnostic plugs on the GE Mastr II circuit boards. They sell for between $50 and $100 on eBay. You can use a standard volt meter instead, but you have to be careful to count the pins. You also need a signal generator tuned to your repeater's Tx and Rx frequencies.
GE Mastr II Programmable Channel Guard CTCSS Tone Decoder/Encoder
Spec sheet for the Mastr II CTCSS tone unit.
NHRC.net's Mastr II VHF Tuning Instructions
On the NHRC.net site they have a really good summary on how to tune up the Mastr II receiver.
Repeater Builder's GE Mastr II Documentation Database
This section of Repeater Builder's has every LBI (known as "Lynchburg Book of Instructions" because Lynchburg, VA was the home of GE's land mobile radio division from 1958 on.
Hamtronics R303/TD-5 Receiver/CTCSS installation
In April 2010 we shut down the GE Mastr II Receiver unit and replaced it with a Hamtronics R303 unit. Photos and short descriptions are here.

Wacom WP-639 Duplexer
Wacom WP-639 Duplexer Image
The Wacom WP-639 Duplexer (also known as BpBr Circuit Duplexer) is a great little unit to allow us to transmit on 145.11MHz and receive on 144.51MHz on the same antenna. Which I recon is what a duplexer is supposed to do. For a sample of the band separation curve response capabilities of the unit at 600KHz and 1MHz offsets, click here. Wacom Products was based in Waco, TX but I cannot locate them any more. WP-639's are still available on various ham equipment sites but they are getting about $1400 these days.
Wacom WP-639 Field Tuning Instructions
This is a really good document if the Duplexer ever gets out of tune.

SCom 7K Repeater Controller
Controller Audio Files
These are the audio files that are copied into the SCom 7K controller.
S-Com 7K User Manual
This is the user manual and more importantly the programming manual for the controller. Programming is done by pressing DTMF tones on a transmitter tuned to the repeater's frequency. As much as you might like to have a GUI interface program to make this work, there is not one. SCom has a fancified text file editor, but in the end, it's easier just to read this manual, figure out what you want to do, and key it in.
S-Com 7K Schematic
S-Com 7K Repeater Controller
This is the web site of the makers of the SCom 7K.
Vyex web site
Makers of the 7K-DAB (Digital Audio Board) for good quality voice synthesis on the SCom 7K repeater controller. The best part of the 7K-DAB is that it adds a serial DB-9 connector to the SCom that allows us to program the controller using the Echolink computer. Click HERE to download the user manual for the 7K-DAB.

Echolink and other Internet Repeater Linking Resources
Echolink
We are node number 237900 on Echolink. For more information on how Echolink works, see their web site.
What does the W4RFR/R-Echolink Interface Look Like?
Getting the Internet up to the rooftop on 3322 was not easy. First we thought about getting a dedicated DSL like up there but that's expensive. I (KF4ZIS) only live 1.2 miles from the repeater site, so we bought a NanoStation 5 wireless Internet link. Believe it or not it kind of works. This diagram is a pretty good depiction of how it all hooks together. Click on the following links for additional informaiton.
Line of site map of the 4200-3322 link
4200 rooftop analysis of the link

W4RFR/R-Echolink-Wx Block Diagram
Interfacing the SCom 7K controller to Echolink is not trivial. The SCom 7K has a mail DB25 on the back that allows Rx and Tx interfacing on all components controlled. We developed this block diagram to make a little bit of sense out of it. We use Rx1/Tx1 for RF repeater ops, Rx2/Tx2 for Echolink ops, and Rx3 for emergency weather radio interfacing (not yet implemented as of 7/4/2007).
W4RFR/R-Echolink-Wx Wiring Diagram
This is the definitive wiring diagram to get the ULI Echolink Interface patched into an SCom controller. If you use this and it works, please make a small donation to the repeater club on the home page! It does work, and it is indeed tedious work, especially if you use crappy components from Radio Trash. Do yourself a favor and buy good quality DB25's... Two cables later we finally came to that conclusion.
I-Link Hardware
Makers if the ULI Echolink interface.
KH2D's Echotime TTS Plus
This nifty program drives the ident and information system on the repeater. It uses a speech synthesizer to digitize IDs, current time, instructions and alerts, and weather reports.
Internet Radio Linking Project
An alternative to Echolink. Some Hams like IRLP better than Echolink because it only links radios to radios and there is no workstation work without a physical radio allowed.
The Asterisk app_rpt project
The integration of 2-way radio systems and reasonable telephony. We have not looked into this.

Associations and Regulations
www.SERA.org
The Southeastern Repeater Association provides voluntary frequency coordination for amateur radio repeaters in Georgia, South Carolina, North Carolina, Virginia, West Virginia, Kentucky, Tennessee, and Mississippi. The W4RFR/R repeater was re-coordinated by SERA in March of 2007 for its current location.

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