443.075 MHz FM & P25 TX/RX, VHF remote base, RC210 controller & DMR Bridge

Rear view of UHF TX/RX and VHF remote base shelves

The supervisor (and wire thief)

Motorola T1500 duplexer and MASTR-II 100W PA

K5TRA 443.075 (123.0) Repeater

The 443.075 repeater is an open repeater for FM and P25 operation. P25 operation locks out FM keying and vice versa. The FM mode requires 123.0 PL.Four Yaesu FT-7800 radios are used for UHF transmit and receive. An Icom IC-208H is used as a VHF remote base. The PA is a 100W GE MASTR_II. A pHEMT preamp is also in the receive path along with cavity preselector filter. The duplexer is a Motorola 4-cavity T-1500 type. It provides a little over 1 dB insertion loss with isolation near 100 dB. An ARCOM RC-210 3-port controller supports (1) repeater, (2) VHF remote base, and (3) Allstarlink operation. Any combination of these ports can be connected from DTMF control. The Linux Allstar server also supports EchoLink and IAX operation. The antenna is a Phelps Dodge Stationmaster-II.

P25 operation on 443.075 MHz was is in Austin has been generating local interest in the mode. That interest led to a request for a P25 Texas reflector; so, the 10888 reflector was created for that purpose. I also wanted to be able to monitor several P25 reflectors (simultaneously scanned) with one radio. The solution for me was to build an analog bridge between an local ASL node and a P25 gateway (pointed to another reflector). The other motivation was the interesting technical side of the project. That work is documented in the link below:

DMR operation was recently added to 443.075 MHz. The color code is 1. Static TGs on TS1 are 3148 (TX) and 3104 (AZ). Static TGs on TS2 are 114802(N5OAK), 314859 (K5TRA), 314891 (N5SIM-Troy).

P25 Analog_Bridge and P25 Reflector    - "HOW TO" DETAILS

444.5 MHz TKR-820 repeater with allstarlink interface - Johnson City TX

K5TRA 444.500 (110.9) Repeater

A Kenwood TKR-820 provides the core repeater. A Motorola 4-cavity T-1500 duplexer provides good isolation (~100 dB) and low insertion loss (~1 dB). A Raspberry Pi 3B is used to provide both repeater controller operation and Allstarlink operation. The antenna is a Diamond X-200A.

444.7125 MHz   P25 Repeater

Rear view of    444.7125 MHz   P25 Repeater

K5TRA  444.7125  P25 Repeater

The 444.7125 MHz repeater is an open repeater for P25 operation. A pair of Kenwood TK-840 radios are used for TX and RX. A RPi 3B+ and N3XCC MMDVM provides the controller functionality. The duplexer is a 4 cavity BP-BR from DB Products. Power output is set to 30W after duplexer losses.


The (K5TRA) 443.075, 444.500, and (W5KA) 444.200 repeaters are normally linked (via Allstarlink). A convenient HUB node is provided for linking (48398). Please feel free to connect as long as DTMF / courtesy tones / ID tones / etc. are not transmitted over the link, and other large networks are not bridged.

Click for current connections

Some mobile installation photos