BEECN SW Portland Repeater

BEECN UHF radios operate on line-of-sight. That can make comms in SW Portland's hilly neighborhoods challenging. To work around this issue, PBEM has fielded a UHF repeater in SW Portland for BEECN. The repeater is stored near Markham Elementary School, with the intention that it would be deployed in the field behind Markham ES if a crew of volunteers can access it and stand it up. The purpose of this article is to describe equipment specifications; and the deployment, set up, and demobilization of the BEECN repeater.

In the BEECN journal, the repeater is called the SWR1 SW Repeater. BEECN volunteers in Southwest Portland can pass radio traffic through it by setting their BEECN radios to channel 7. There are four essential parts to the BEECN repeater kit: the repeater, the antenna, the mast, and a power source.

Relevant Documents	Updated
Icom repeater base station spec sheet	2008
BEECN repeater RFQ and purchase documents (useful for specifications)	2014
BlueSky BEECN Repeater Mast System Manual	2016

Repeater Kit Specifications

Repeater: Model IR3UG UHF Portable Repeater

The repeater is a Model IR3UG UHF portable UHF repeater, ruggedized for military use. PBEM purchased it from Tactical Electronics Corporation.

• Radio frequency (RF) output of 35 watts;
• Frequency range of 450 - 470 MHz.
• Site requirements: 7 m minimum antenna distance with 5 MHz frequency separation.

Comprises the following integrated as a system mounted in a Pelican enclosure:

• Repeater/base station Icom R6000TEC. Programmed on 452.2375 MHz TX & 461.4750 MHz RX. Compliant with FCC and NTIS technical standards.
• DC power subsystem. Provides operating voltage from 100-250V AC, 12V DC, or solar source. Front panel metering of DC volts level.
• RF monitor subsystem. Front panel metering of RF output power.
• Duplexer. Allows the repeater to work with a single antenna. Tuned as per above frequency pair.

Physical parameters

• 20" width x 8" height x 8" depth. Weighs 42 lbs.
• Operating temperature range is 14°F to 130°F.
• MIL-STD-810F for shock, rain, vibration.
• .5 m drop.

Antenna: MaxRad Antenna

The antenna, which should be stored in the mast bag and affixed already to a segment of mast, is a portable MaxRad MFB 4505 UHF vertical 4.5dBd gain antenna. This antenna was spec'd out with the original repeater kit and includes 15 meters of connectorized coaxial cable.

Mast: BlueSky Mast AL2 Standard Series

In addition to the mast sections, the mast kit includes a tripod with a compass and levels, as well as a stake kit and primary guying to keep the mast secured to the ground.

The mast kit and antenna are stowed in a 54" x 14" x 14" wheeled carry bag for easy transport. One person can carry it with difficulty; better to have two.

Power: ZAMP Solar Generator

Output of 200 watts for charging AGM Group 27 battery, and directly powering PC, tools, etc.

Program/Policy Background

File:2025.04.06.SquirrelFood.jpg

And here is why you don't let squirrels get into your equipment bags.

PBEM Operations purchased the repeater kit in the Spring of 2014 and it arrived at PBEM in July that year. It was tested twice, and then stored at the Jerome Sears Center. Institutional knowledge on how to use the repeater was forgotten at PBEM. A family of squirrels also took up living in the mast bag and they ate one of the instruction manuals. The repeater was moved to volunteer care in 2024 after PBEM was booted from Sears. The repeater was successfully tested again in April 2025.

Note about the mast kit: the BlueSky mast was cannibalized out of PBEM's Go-Kit program because it is superior to the mast kit spec'd with the repeater kit. The original mast was a 32 ft. tubular antenna mast in four foot sections. However, the mounting tripod to that mast is missing.