UARC Logo

The UARC 146.62 Repeater System

Farnsworth Peak and Scott's Hill

Synchronous/Voting Repeaters

Site coverage analysis
 


How to interpret these maps:

PLEASE READ THIS!

It should be understood that these maps are based on predicted signal strengths, using high-resolution (1 arc-second) terrain database data and state-of-the-art propagation models.

Because these are predicted values, they should be used only as general guidelines for determining coverage in a particular area and they should be more-considered as indicating the probability of coverage rather than an absolute determination.

While these propagation calculates take into account most of the common effects noted, such as Fresnel, various diffraction, etc., they cannot be relied upon to account for all modes of likely propagation - most notably, reflections that might enhance (or degrade) signals in certain locations such as narrow canyon, more-distant valleys, etc.

When the predictions made by these maps have been compared with the known coverage of repeaters that have been on the air for a long time, they have generally been found to be somewhat pessimistic:  It is not uncommon for usable coverage to be noted in areas not so-indicated.  In many cases, this "improved" coverage has been, in fact, due to reflections and refractions that cannot reasonably be predicted using the database and the propagation models.

Finally, when interpreting these maps, note that for far-distant areas that seem to have coverage, closer inspection will reveal that such coverage is generally confined to mountain tops and that the one must not be mislead by thinking that coverage is likely in nearby areas that are likely to be more accessible.

Calculated signal levels:

For these maps, the hypothetical receive antenna is an omnidirectional antenna with a gain of 0dBi using an antenna 3 meters above ground.

The coverage maps are color-coded showing expected signal strengths, ranging from -67dBm (100 microvolts) to -127dBm (0.1 microvolts.)  This ranges from signals that are quite strong to extremely weak.  The bottom end of this range (-127dBm) will generally result in extremely noisy and possibly un-copyable signals, but in those areas even a modest gain antenna (such as a 3-5 element Yagi) would likely be able to boost them from "barely detectable" to "usable."

In general, the colors may be interpreted as follows:

COLOR
 Signal quality (Mobile/Home installation)
 Signal quality using an HT (Handie-Talkie)
RED
 Extremely strong.  If you have trouble at home or in your car, something is wrong...
 Good coverage using an HT and a reasonable antenna
ORANGE
 Extremely strong.
 Ok, but you may need to use a better-than-stock antenna for good signals to the repeater
YELLOW
 Good.  Low power (5 watts) and a rooftop antennas should provide excellent results.
 You'll likely need a "real" antenna - something much better than a rubber duck.
GREEN
 Good.  You should have no trouble hearing it fairly well, but you may need higher transmit power to get into the repeater.
 You'd better be using a gain antenna (such as a Yagi) and/or find a hot spot.
CYAN
 Fair.  You should generally be able to hear the repeater, but it will likely be noisy in many areas.  You can probably get into it if you find a hot spot.  If you are at home, you'll likely want to use a gain antenna (such as a Yagi) for reliable operation.
 You are pushing your luck, but you may be able to find a hot spot if you use a gain antenna.
LT BLUE
 You'll likely need to hunt around for coverage in a mobile, but you'll probably be OK with 50 watts and a gain antenna at home.
 Coverage is possible, but unlikely.
DK BLUE
 You are pushing your luck in a mobile.  A good gain antenna and high power may work, but don't depend on it!
 Coverage is unlikely.
NO COLOR
 Coverage is unlikely.
 Coverage is very unlikely.

IMPORTANT NOTE:

These maps have features that are, themselves, in color. 

For example, the Great Salt Lake is blue, so "Red" and "Orange" coverage over the lake shows up as a sort of muddy brown/green color.

Please take this into account when you are reviewing these maps!

Parameters used for the coverage calculations:

Farnsworth Peak antennas:
Scott's Hill antenna:
User antenna (i.e.. the "receive" antenna in the field):
Coverage Maps:

Images are .gif, 700-900k each.

Farnsworth Coverage:

These maps describe the predicted coverage of the existing 146.620 repeater atop Farnsworth Peak.
Large map - Covers northern Utah and parts of southern Idaho, southwest Wyoming, and northeast Nevada.
Medium map - Mostly northern Utah
Small map - Salt Lake and Utah counties, mostly...
Scott's Hill Coverage:

These maps describe the predicted coverage of the proposed 146.620 repeater atop Scott's Hill.
Large map - Covers northern Utah and parts of southern Idaho, southwest Wyoming, and northeast Nevada.
Medium map - Mostly northern Utah
Small map - Salt Lake and Utah counties, mostly...

Combined system Coverage:

These maps describe the predicted coverage of both the Farnsworth and Scott's Hill repeaters together.
Large map - Covers northern Utah and parts of southern Idaho, southwest Wyoming, and northeast Nevada.
Medium map - Mostly northern Utah
Small map - Salt Lake and Utah counties, mostly...

Predicted overlaps areas:

The maps below are different from those above in that they show, in RED, those areas in which the transmitted signals from the two repeaters are likely to be within 10dB of each other.  In these areas, it is likely that one will often hear both transmitters at the same time.

Due to the fact that the transmitters will be with a few Hertz of each other, combined with the fact that the "capture effect" is enhanced by this, and also that the transmitters will be carrying the same audio, the likelihood of destructive interference is quite small.  Testing has shown that given two transmitters operating within a few Hertz of each other, carrying the same audio need only 2-4dB of difference to avoid any obvious degradation.  Due to the nature of propagation - especially in those areas prone to overlap - it is unlikely that the user will dwell in an area in which the two signal levels are so-precisely matched.
Large map - Covers northern Utah and parts of southern Idaho, southwest Wyoming, and northeast Nevada.
Medium map - Mostly northern Utah
Small map - Salt Lake and Utah counties, mostly...
 
Analysis:

The coverage of the 146.620 repeater is quite well-known and generally reflects that shown on the maps

The predicted coverage of the Scott's Hill repeater (and the observed coverage of an existing 2-meter repeater nearby on 145.270) is similar to that of the 147.180 Hidden Peak (a.k.a. Snowbird) repeater, except that Scott's has poorer coverage toward the south.

The combined coverage of the two repeaters should allow for coverage along Interstate 80 from Wendover to Evanston, not to mention previously un-covered areas of Heber Valley and the Park City area.

The are no severe "overlap" areas in the main population areas served by the existing Farnsworth repeater.  Near the Salt Lake area, the only expected overlaps frequented by users are predicted to be in the canyons of the Wasatch (Parleys, Big and Little Cottonwood Canyons, Mill Creek, etc.) where the signals from Scott's are expected to augment and improve coverage.

Reported coverage:


Go to the UARC repeater page.

This page last updated on 20110630