Page last updated: May 29, 2015.
The Eagle, MI area GMRS repeater went live in August 2014.This is a privately owned repeater but your free use is encouraged!
  • Program your radio for Tx: 467.700 MHz , Rx:: 462.700 MHz. (The repeater does the opposite: Tx: 462.700 , Rx:467.700)
  • Public PL (CTCSS): 100.0 Hz, Travel: 141.3 Hz
  • Mobile Coverage: Approximately 12 mile radius. Handhled: Approximately 4 mile radius.
  • Solar Powered using (20) Renogy RNG-100D 100 watt panels, (2) Midnite Solar Classic 150 Chargers, (4) 420 Ah ea. 6v Trojan L16P-AC batteries wired for 12 volts using 1/0 wire (Total 840 AH at 12v).
  • Motorola MSF5000 C74CXB7106BT at 48 watts output after duplexers with AR2 preamp. Connect Systems Inc. CSI TP-154
  •  Controller
  • Decibel DB420 antenna with a 10.4 dB gain at 50' height mounted on Rohn TRTAG2 tripod roof mount on top of my house
  • TG Electronics N8XJK 80Amp Boost Regulator, set to 14.8v, to maintain consistent repeater output.
Private pl's available free by request for casual users. Email:

Backup repeater: Kenwood TKR-820 at 25 watts output.

Thank you for visiting, 73's,
-Kim , , WQSL732
Decibel DB420 Antenna as mounted on roof
(TV antenna below the DB420)
The Motorola MSF5000 with front panel removed.
MSF5000 with solar equipment.
Kenwood TKR-820 backup repeater on shelf.
Repeater Tuning Equipment
(A special thank you to for excellent instructions on building the MSF5000 and TKR-820 repeaters)
HP / Agilent 5980 E6380A: 0.4 to 1000 MHz &1.4 to 2.0 GHz Spectrum Analyzer / Tracking Generator with full duplex monitoring, RF Power Meter, Signal Generator, and much more. Max 75 watts input
Marconi 2955A: 1.5 - 1000 MHz Spectrum Analyzer, Signal Generator, RF Power Meter, Frequency Counter, Duplex RF Tester, SINAD & S/N Meter, Distortion Meter, AF Voltmeter, AF Counter, Oscilloscope, DCS/CTCSS/DTMP Code Decoder & Generator
Motorola MSF5000 Metering Panel: This kit (including the tuning tools kit) made tuning the repeater MUCH easier. Donated by Jeff Frank, N8HEE. Thank you, Jeff!
Motorola RIB and MSF5000 Cable: The universal Radio Interface Box (RIB) requires the cable specific to the MSF5000. The software is Motorola's Radio Service Software (RSS) RVN-4077. I had to run this software on an old PC that had old-fasioned serial ports. The PC was also donated by Jeff, N8HEE.
Kenwood KPT-50: This programmer is required to program the Kenwood TKR-820. Once programmed, I used the Marconi 2955A to align the front end and adjust RF out. (The repeater can be programmed without a programmer, but it is much more difficult and requires excellent soldering skills).
(20) 100w Renogy Solar panels.
(Picture is outdated and only shows 12 panels)
Here's a summary of the steps used to get the full functioning repeater up and running:
First, I wish to thank Jeff Frank, N8HEE for donating the following equipment which made this repeater possible:
  • MSF5000 #1 C74CXB7106BT UHF repeater (main unit). (Jeff originally donated it to my father whom gave it to me.)
  • MSF5000 #2 old-style analog UHF repeater with 12v battery backup power supply (for parts)
  • Test Panel with complete tuning equipment (RF infusion cable, Allen wrenches, tuning screwdrivers, etc.)
  • Older Dell PC computer
Also, thank you to the contributors at for all the documentation.

I was given an MSF5000 CXB UHF repeater from my father, K8VEB (which was given to him by Jeff, N8HEE). I went to Jeff's shop and used his equipment to program the repeater. Then I took it to a professional, Brain, to align it but he was unable to get the Injection Filters (IF) to align. He said the RF tray was bad.

Jeff offered to let me use one of his backup MSF5000's and he'd keep the "bad" unit.

I wanted to run the repeater off my 12v solar system (uses 17 watts at idle on 12volt vs. 68 watts on 120v), so I needed a 12v battery backup power supply. Jeff only had one repeater with the 12v PS, but it was the old analog system, so he let me take a repeater with the newer digital-capable SSCB (Motorola's built-in controller) and the one with the 12v battery backup power supply.

The main MSF5000 was a digital-capable CXB version. To program it, I needed a Motorola RIB and MSF5000 Cable. I purchased those from eBay. I already had Motorola's Radio Service Software (RSS) RVN-4077 to program the repeater, but had to use the older Dell computer because it was capable of running DOS and had an RS232 com port. Next I programmed the MSF5000 #1 for my frequencies.

Now it was time to tune and adjust the repeater.
I adjusted the Tx and Rx VCOs first. I turned the Allen wrench until the Rx Lock light was on and then again until the light went out. I then adjusted back the Allen wrench to the approximate center of the Rx Lock. I then repeated these step for the Tx VCO.

Next I adjusted the Injection Filters (IF), but the MSF5000 #1 RF Tray wouldn't adjust to my Rx:467.700 frequency.  Upon looking at the wiring diagram, the RF board is only spec'd to receive up to 464.3 MHz... it apparently doesn't like 467.7 MHz.

So I tried the MSF5000 #2 RF Tray. Since it had the analog controller, I had to swap controllers which wasn't too hard to do, but time consuming. I discovered that the receiver preamp was not working on RF Tray #2, so I had to steal RF tray #1's preamp. Finally, after adjusting the IF and the Selection Filter (the band-pass filters), it was working... and luckily, it tuned to my frequency better than the RF tray #1. It still wouldn't tune precisely, but it tuned better.

Next, I tuned the Transmit Filter (TF) (the duplexer). I bypassed the prefilter because Brian (the professional) stated they often go bad. He recommended I put a band-pass filter inline, but due to space constraints, I used a barrel connector to bypass the preselector. I have not noticed any degradation of performance yet.

Now the 12v DC conversion:
I plugged in the MSF5000 #2's power supply with 12v battery backup module, but it didn't work. After reviewing both power supply schematics, I was able to pull the DC module from MSF5000 #2 and install it into MSF5000 #1's power supply.

I purchased a pair of Anderson Power Pole 75amp terminals, connected to my 12v batteries and everything lit up. Everything was working until I transmitted: the PA kept shutting down. I had previously set the PA to 48 watts, but it was apparently too much for the 12v system. After adjusting it to 38 watts, it began working well.

Now to install the Advanced Receiver Research (AR2) preamp:
First, my goal was to keep all hardware contained within the MSF5000, but to install the AR2, I had to install another duplexer (I have not found a way to bypass the RF Tray's built-in band-pass filters (BPFs)). Luckily, I was able to use MSF5000 #2's TF, which was rack mounted. So I simply tuned the second TF to my receive frequency, mounted it into the repeater, and placed the AR2 inline. It all works now and is self-contained!

Now to install the CSI TP-154 Controller:
Since I needed to use multiple PL/CTCSS codes, I had to hard-wire the controller to the SSCB. Otherwise, the SSCB would filter out my outgoing PL/CTCSS tones. I used the article Motorola MSF5000 Interfacing Signals from and soldered the connections according to the Zetron 38A controller.

Eliminating the Battery Backup Alarm:
The repeater worked great, but the SSCB kept adding extra beeps indicating it was running on battery power. A quick look at the schematic revealed that pin #6 of J603 (the plug that goes from the power supply to the RF Tray) was the AC FAIL wire. Using a voltmeter, I discovered that I needed to inject 5v into the orange wire (pin #6). The easiest source of 5v was the blue wire (pin #5). I simply removed the orange wire, stripped it back, and inserted it into pin #5 underneath the blue wire.

Adding the Battery Booster:
The voltage of my battery bank varies significantly, from 11.0v to 14.8 volts which was causing my PA output to vary sigificantly. To maintain a consistent 48 watts output, I purchased and installed TG Electronics' N8XJK 80Amp Boost Regulator and set it to 14.8v.
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