Forgotten Bands Network of the Ozarks

The Forgotten Bands Network of the Ozarks (FBNO) is a linked repeater system intended to link together the “Forgotten Bands” repeaters in the Springfield Metropolitan area to allow amateurs to experiment with these crazy bands that few ever use. The system is mainly funded by James Adkins, KB0NHX, but the Nixa ARC also supports one repeater currently on the system.

Below is the list of repeaters on the network:

Repeater
Output
Repeater
Input
OffsetEnc
PL
Dec
PL
LocationOwner
444.875449.875+ 5 MHz162.2 Hz162.2 HZCox South SpringfieldKB0NHX
927.0125902.0125-25 MHz162.2 Hz162.2 HzNE SpringfieldK0NXA
927.1125902.1125-25 MHz162.2 Hz162.2 HzCraneKB0NHX
1285.0501273.050-12 MHz162.2 Hz162.2 HzCox South SpringfieldKB0NHX

All 4 repeaters are linked together via the 444.875 MHz “Hub” linking repeater.

When a Tornado Warning is issued by the National Weather Service for Christian or Greene County, you will hear the system announce “Tornado Warning” and the system’s weather radio will activate and play the NWS warning out on all repeaters on the system. When audio warning is completed, the weather receiver shuts off and the system will then play the old KTTS Tornado Warning alert every 5 minutes until the warned period expires

Icom IC-RP1210 1285.050 (-) Repeater, PL 162.2 Hz & TX RX 28-97-01B duplexer

The repeater, and duplexer, was donated to KB0NHX by Lee Ward, K0LW, and was previously stashed in his “radio barn”. The repeater had not been powered up or operational in many years.

After allowing the repeater to warm up and “idle” for about a day, I adjusted the VCO’s and the transmitter to bring it back on frequency. Lastly, the receiver front end was adjusted for maximum sensitivity on 1273.050 MHz.

Since I did not have a way to re-program the eProm used on the internal controller and it lacked the ability to link to other repeaters, I then installed wiring from a DB-9 in the back of the repeater to spots on the Icom IC-RP1210 repeater for remote PTT, COR detect, TX audio and RX audio to feed an SCOM 7330 controller.

Perhaps the most challenging part of the project had to do with the PL tones. Since the repeater had a non-functioning TS-64DS tone decoder board already installed, I replaced it with a new one to give the SCOM 7330 the CTCSS detect I needed. For encoding, I decided to use the SCOM 7330 PL tone encoder. This would allow me to more easily control the PL tone deviation and change it on the fly without opening any covers!

Icom IC-RP1210 TX PL Encode location

With the help of Jeff Liebermann, AE6KS, who has an RP-1510 on 2-meters, we were able to determine where to inject the PL encode audio from the SCOM 7330 controller. After a bit of experimenting, I installed a 100k resistor (instead of the 47k we started with) to get the proper deviation for the repeater.

On June 12, 2020, the 1285.050 (-) Repeater went live from Cox South Hospital in Springfield, MO

1285.050 & 444.875 repeater antennas

Both the 1285.050 (-) and 444.875 (+) repeaters are fed with about 30′ of Andrew LDF4-50 1/2″ heliax to help minimize system loss.

The 1285.050 repeater has been worked by mobile stations in Aurora, Bolivar, Nixa, Ozark and Seymour to name a few local communities. Coverage has been better than expected for the 23cm band!

Kenwood TKR-850 Repeater for the 444.875 (+) Repeater, PL 162.2 Hz with Astron power supply and SCOM 7330 controller

The Kenwood TKR-850 444.875 repeater serves as the “hub” repeater for the Forgotten Bands Network of the Ozarks. It is co-located with the 1285.050 atop Cox South Hospital near US 60 & National Avenue.

The repeater is a 25-W repeater and provides good mobile coverage in the Springfield Metro area.

The repeater serves to link together the 927.0125 (-) PL 162.2 Hz K0NXA repeater in Northeast Springfield and the 927.1125 (-) PL 162.2 Hz KB0NHX repeater in Crane.

A transmission on any of the 4 repeaters on the Forgotten Bands Network will be transmitted on all 4 repeaters simultaneously similar to the architecture of the Southwest Missouri Linked Repeater System

75-Watt Motorola Quantar Repeater with SCOM 7330 controller and TX RX duplexer – Crane 927.1125 (-) Repeater
75-Watt Motorola Quantar with duplexer, Motorola CDM-750 UHF link radio and CAT WX-200 weather receiver
CAT WX-200 Weather Receiver & Motorola CDM-750 UHF link radio to the 444.875 (+) Repeater
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