443.900 Repeater Upgrade – February 20

We will be upgrading hardware at our 443.900 MHz Butler County EOC site on February 20th, 2021.  A two hour maintenance window will start at 11:00 AM and conclude at 1:00 PM. The 443.900 repeater will be intermittently off-the-air during the maintenance window.

The upgrade will involve replacing the existing Icom IC-RP3010 FM repeater (right) with a Yaesu DR-1X System Fusion repeater (above).

After the upgrade 443.900 will support both analog FM and digital voice C4FM modes.

Information on C4FM and System Fusion can be found here: What is System Fusion

Icom IC-RP3010 FM UHF Repeater

What This Means for Current Repeater Users

Repeater operations will continue as normal for most users. The repeater will auto-detect what mode you are transmitting and shift between analog voice and digital voice accordingly.

It is important to note that the repeater can only operate in one mode at a time. It will not covert analog transmissions to digital (a process known as transcoding) or vice versa.

  • Analog operators should set both the PL Tone and Tone Squelch on their radios to 131.8 Hz. While only an uplink tone (PL Tone) is needed to access the repeater, a downlink tone (Tone Squelch) can be used to filter undesirable audio from any digital transmissions.

    Or put another way…

  • Un-decoded digital voice traffic sounds similar to the “modem” sounds you’ve become used to hearing during our Wednesday Night Digital Training Nets. If this sound is annoying or disruptive you can use your radio’s CTCSS tone squelch option to mitigate.

  • Analog operators can interrupt a digital QSO at anytime by keying the repeater. The repeater’s auto-mode detection will drop the digital transmission and reset all stations (digital and analog) to analog FM.

What This Means for C4FM Capable Stations

If you have a radio that supports C4FM digital voice then place your radio in Automatic Mode Select (AMS) mode and set the C4FM mode to either DN (digital normal) or VW (voice wide). As long as  you have enabled AMS then your radio will follow the repeater through digital/analog transitions.

This is a Test and Only a Test

We’re upgrading the repeater at the Butler County EOC as part of a trial to evaluate how digital voice modes fit into the long term communications needs of our club. There are some technical and performance obstacles to overcome with this particular hardware deployment.  If performance falls short of expectations we will revert to the RP3010 analog repeater.

In other words… we’ll see how it goes.