443.800 Repeater System

Overview

The 443.800 system in Cedar Rapids, Iowa, is an amateur radio service repeater. This privately sponsored system boasts fairly good handheld range in the immediate metropolitan area, and nice mobile coverage in the surrounding area, including all of I-380 in Iowa, parts of I-80 near Iowa City, portions of US 20 from Waterloo to Manchester, portions of US 30 from near Belle Plaine to Stanwood.

The repeater had been available on EchoLink® courtesy of W0IY, the node number was 162535. Unfortunately, lightning has taken its toll on the portions of the system, and EchoLink® is no longer available

Some photos of a site visit on 1/8/2007 are available on our gallery page. This includes captions and some annotations for those unfamiliar with repeaters or Micor chasis.

Equipment

Currently, the radio equipment consists of Motorola Micor repeater/station system at a commercial site. The repeater shares antennas with commercial band (450-470 MHz) systems. Separate receive and transmit antennas are used with receive a pre-amp/splitter and a transmitter combiner.

A UHF Repeater Project

Coverage Analysis Plots

Here's some coverage maps from Splat!. Fortunately, Bdale packaged splat for Debian, so its easy to install and upgrade. The path loss map color map is at the bottom of the full resolution image, and is provided at right in a re-arranged form.
Thumbnail Description Moderate size Full size
PNGJPGPNGJPG
Line of sight 700x700
(488153 bytes)
(Unreadable)
700x700
(78729 bytes)
(Unreadable)
2400x2400
(2295398 bytes)
2400x2400
(609433 bytes)
Longley-Rice_coverage_analysis (Path Loss) 700x700
(488153 bytes)
(Unreadable)
700x700
(78729 bytes)
(Unreadable)
3600x2400
(3234248 bytes)
3600x2400
(2977324 bytes)
Zoomed (local) Longley-Rice_coverage_analysis (Path Loss) 900xN00
(239939 bytes)
900xN00
(179055 bytes)
Zoomed (local) Line of sight 900xN00
(239939 bytes)
900xN00
(179055 bytes)

Some history

Please "repeat"/(reload) for random image

The 443.800 MHz repeater started as a project in the late 1980's. It was coordinated in 1989, and has been running in the back of KA0YSQ's garage on and off since then. The "group" at its genesis was KA0YSQ and KD9KX, with N0LNO and WA0RJT getting involved very early. It's been a single site repeater, with separate tx/rx antennas. The original repeater is based on a GE MASTR EXEC II UHF mobile phone. The squelch circuit and controller were home-brew and lived inside the case of the GE.

Plans were to eventually support a remote base system for linking to 2 meter repeaters, or monitoring/operating an HF station. The general goal was experimentation and low-key operations. Expectations from non-builders or pressures from dues-payers were to be avoided.

15 years later... a new beginning

In 2004, there was renewed interest in having the UHF machine available to link to HF and/or internet linking. As luck would have it, many of the now 30-year-old solid state base/repeater systems for land mobile (e.g. UHF business band) were losing their popularity (and value). This seems fortuitous for the radio system builder with a very tight budget.

After some casual inquiries into the availability of used Motorola gear, we were confronted with the availability of some Micor station gear. Crystals were ordered, and a system was "down-banded" to amateur frequencies.

In the same time period, the discussions on the local repeaters led to the availability of a new home at a better site. On March 2nd, 2004, a Micor repeater station was installed at the new site, with excellent results. For a look at one coverage analysis, using John Magliacane (KD2BD)'s Splat package, look at this image (194887 bytes), or check out the coverage part of the gallery below.

Repeater-related Links

EchoLink® is a registered trademark of Synergenics, LLC.


Ron Luse
Last modified: Mon Jan 22 21:57:13 CST 2007