Repeater Construction, History, and Technical Details

South Clatsop county has historically been an area with poor radio coverage. In order to reliably hit the 146.66 from my house in Arch Cape I resorted to using a large vertical antenna on top of my house with an amplifier running 90 watts. Certainly not a very portable method of operating. I had wanted a local link to the 146.66 repeater network that covered the northern area of the county for as long as I can remember. This finally became a reality in 2002. As I recall the story, Bernard, N7DAL, was into high angle rescue climbing and another fellow also involved in this activity worked for Willamette Industries, the owner of the forest land behind Cannon Beach and Arch Cape. After repeated explanations of the benefits of amateur radio Bernard got the go ahead to begin discussions of locating a radio repeater on the Willamette Industries forest land.

Frank, NM7R, put his flying talent to good use with a survey of the area in south Clatsop country along the coast. Bernard then began ground explorations on his mountain bicycle armed with a digital camera borrowed from Jay, W7FBM. The survey turned up a good spot to the east of the north end of Arch Cape. From the ridge at 2400 feet we have line of sight down to both Cannon Beach and Arch Cape. Coverage, as seen on this map, is good along the coast from Arch Cape on up to Astoria. The mountain ridge of Angora Peak limits coverage to the south. Negotiations for a lease of the land progressed and permission for a 4 foot by 4 foot building was secured. And yes, we wish it was 6 by 6 on every visit. Land ownership moved to Weyerhaeuser, and now Stimson Lumber.

Concrete work for the building base and tower is completed on a cold March day in 2002.

The building as it looked on a sunny day at the end of April, 2002. The 4 walls and roof were assembled in Jay's garage and hauled to the site. At this stage they were painted green. The building was later covered with metal siding donated by Greg, N7RIA. The wood frame seen here is ready for the first two solar panels used for power.

May first, 2002, the building sits in the fog with two solar panels in place and the antenna up. An additional two solar panels were added after the repeater had been operating for a while. There are now two additional antennas on the west side of the building next to the tower.

Bernard applies paint to the door May 18, 2002. The installaiton of the metal siding is in progress.

Bernard's work gets careful inspection by the canine crew. May 18, 2002.

A look inside the building as construction continues. The charge controller for solar system is seen bolted to the wall.

The two Icom IC-2AT radios that provide the core of the repeater. These feed an external amplifier giving 20 watts when the amplifier is enabled. Manuals here.

Technical Details
The repeater is built using 2 stripped Icom IC-2AT 's handhelds  installed in separate RF tight boxes, extra heat sinks and feed thru caps. and ferrite  beads on all wires. The controller is a CAT-300, with CommSpec TS-64 sub tone board.

Telemetry is provided by a Kantronics KPC3 Plus TNC and another Icom IC-2AT. freq. is 144.93mhz.   The Kantronics TNC has an analog input feature that Bernard set up to broadcast battery voltage and inside building temperature.

The linking radio is a Icom IC4-AT  (also installed in a RF tight box) it is on 444.775 mhz, set on high power and tied into linking port of CAT-300.
Link yagi antenna is pointed at Wickiup Mountain and the 444.775mhz repeater. The 444.775 mhz and 146.66 mhz repeaters on Wickiup Mountain are wired in parallel and use same RC-85 controller,  what ever comes in 66 goes out 66 and 775 and visa versa. The 145.45mhz repeater on Megler Mountain, Washington is set up the same as 146.74 mhz repeater at Arch Cape. It has a link radio on 444.775 mhz that talks to Wickiup 444.775 and 146.66 repeaters. This permits anything that comes in any of the 4 repeaters to re-broadcasted over the other 3.

The repeater is powered by SOLAR electric system.  We have four US-64 panels 3.88 amps each. Controller is a MARK/15 made by Specialty Concepts, Inc.  We are using four 6 volt deep cycle batteries, wired series/parallel configuration for 12vdc.

The tower uses 2 sections of Rohn 25G, for 20 feet of elevation. Antenna is 2 meter commercial grade radom,  Cavities are WACOM's.

The repeater went on the air in May of 2002. It can transmit low power (handhelds only) or 20 watts with the amplifier enabled. The amplifier can be remotely disabled if the batteries get low. So far we have had no power problems and running the amplifier since the repeater went on the air.

Jay, W7FBM put the first 66 repeater on the air in 1981. The present 66 repeater is the 3rd one built, a modified Motorola Mitrek. The first was 100% home brew, and the next a modified commercial Motorola rack mount base station. The 444.775 repeater is a pair of Motorola Mitrek radios.

Update: In 2011 the link radio was altered to communicate with the 145.45 repeater on Megler mountain. This required moving the link antenna to point north and changing the link frequency. The Icom IC4-AT would not transmit on the new link frequency so it was replaced with a different 440 hand held.

Power requirements measured May 4, 2011:
Standby: 350 millamps,  Transmit: 4.7 amps

Solar Panels are Uni-Solar US64 panels.

Manufacture specification pdf here.

Charge controller is SCI Mark 22.

Manufacturer instruction manual pdf here.

Interior of controller:


Solar panels:


View of Arch Cape from the site:


Note: We are going to change the solar controller to a MorningStar MPPT-45 charge controller.
Short description here and full manual here.

Repeater controller is a CAT-300. Manual for controller here.
List of documents for equipment at the repeater site can be found here.

Back to Arch Cape repeater page.