The Hidden Peak Repeater
About the Hidden Peak Repeater:
The Hidden Peak (located at the top of the
Snowbird tram) is the hub of the Intermountain Intertie.
This system (occasionally referred to as the "Snowbird Link
System") is a more-or-less informal collection of
repeaters located in northern Utah/Southwestern Wyoming, many of
which are supported in part by the VHF Society. This
system is a hub-and-spoke system, with the Hidden Peak site as
the hub. For a detailed map of this system, go to The Intermountain
This repeater first went on the air in 1974 and it still operates from the same site and on the same frequency. During the intervening years, a lot has changed with the repeater: It is now the Utah hub of the Intermountain Intertie and from this site, it directly connects the 147.12, the 146.86, the 147.02 repeaters together, and it also has links that connect it to the repeaters in the southern part of the state and to the Idaho linked system. You may be interested in visiting the Medicine Butte Repeater page as well.
What originally started out as a fairly simple
2 meter repeater using tube-type equipment has evolved into the
linked system that we now use. It has been been built and
maintained, almost single-handedly, by John Lloyd, K7JL with
support from the Utah VHF Society. Owing to this
repeater's location, it is able to cover much of the Salt Lake
valley (particularly the western part) in addition to the
so-called "high valley" communities like Park City, Heber,
Duchesne, and Coalville, to name a few. It is even
possible to work this repeater in parts of western Colorado,
part of southwestern Wyoming, and even as far south as Price,
Utah, if one is in the right location and has a good
signal. Its coverage of the eastern benches of the Salt
Lake valley is somewhat limited, owing to the fact that Hidden
Peak is several miles in from the front range of the Wasatch and
is thus shadowed.
Hidden Peak (or "The Top of the Snowbird Tram")
One of the great advantages of mountaintop sites is that, well, they are atop mountains: They can have excellent coverage, and the view from the site is often spectacular.
One of the great disadvantages of mountaintop sites is that, well, they are atop mountains: In the Utah winter, most mountaintops are inaccessible except by helicopter, skis/snowshoes, and in some cases via snowmobiles and snowcats.
The Hidden Peak site is rather unique among
mountaintop sites in that it is rather easier to access the
mountaintop during the winter than it is during the
summer. You see, during the winter, the tram runs very
frequently: Every time there are enough people to fill the
gondola, it's on its way. During the summer, the tram runs
far less often and one must often wait quite a while for a ride
up or down. Despite the relative ease of access during the
winter, there is no doubt that it is much more comfortable to
work on the repeater and/or its antennas during warm
weather. At 11,000 feet, winter winds are always blowing
and the wind-chill is, well, chilling!
In addition to this UHF repeater, there are
two additional links on the site: A point-to-point link
goes south to Frisco Peak (north of Cedar City) and another link
goes north to provide connectivity to the Idaho system.
Interestingly, there is a mountain directly in the path of the
south link (Lone Peak is in the way, and it is over 200 feet
higher than Hidden Peak.) It was discovered that only
the 125cm band would work for this link (other bands were
tried!) and even though it works, signals are extremely
weak. To get the best possible signals this link uses
beams and fairly high transmit power on each end, low-noise
GaAsFET preamplifiers and low-loss 1/2 inch semi-rigid coaxial
cable. As a result of all of this effort, the path has
proven to be quite reliable.
As with any repeater
system, failures do occur occasionally. Several
years ago, a direct lightning strike damaged/destroyed several
of the radios in the repeater system. The entire rack of
equipment had to be hauled down to the valley (to John Lloyd's
house, actually) and the repeater was, in essence,
rebuilt. More recently, a power supply failed.
This particular Motorola power supply employed a switching
regulator as part of its design and it began to buckle under
the repeater's normal load. Finally, a component failed
such that the power supply wasn't able to start up properly,
so it would shut itself down after such an unsuccessful
attempt, only to try to start again. Each time it went
through this cycle, it sent a voltage surge through the system
which eventually destroyed some on-board regulation circuitry
on several of the repeater controller's boards and the power
amplifier for the link transmitter that connects Hidden Peak
to the southern part of the state.
"How much area does the Hidden Peak repeater cover?"
Determining the coverage area of a repeater in
mountainous areas (like Utah) isn't a straightforward or
accurate process. The very best way is to simply put a
transmitter on the site in question and then see where it
covers. In the case of the Hidden Peak Repeater, there has
been 25 years of experience with its coverage abilities, so
these parameters are quite well known. More recently,
computer signal strength predictions based on actual terrain
modeling have become available. These take into accout the
existance of the mountains and their predicted effects on the
signal strength at the frequency of interest.
The image to the right shows the predicted signal strengths based on computer predictions. The green and brown areas represent good signals while the yellow areas represent weak or nonexistant signals. There are always some very local exceptions to these predictions, of course: There are known "hot spots" well into the yellow areas and, conversely, there are some known dead spots in the green and brown areas. The blue areas are those where coverage is starting to get spotty (but a "hot spot" should be fairly easy to find) and the violet areas are those where a good signal path may be difficult to find.
On the map note that, at first glance, the "yellow" colors around the edges and the brown/orange colors next to the green areas near the middle may look similar. Keep this in mind to avoid confusion.
For more information about the coverage of the
Hidden Peak repeater, go to the UARC Scott's
Hill, Predicted Signal Contours page. This page also
predicts signal strengths from Scott's Hill (to the north and
east of Hidden Peak) and Farnsworth Peak (southwest of Salt
Lake, in the Oquirrhs.)
IRLP connection into the Intermountain Intertie:
The "IRLP" is the Internet Repeater Linking Project - an affiliation of repeater and radio systems that provide connectivity to each other via the internet. This system allows repeater and amateur radio systems worldwide to interconnect with one another. For more information, go to the IRLP web page. For specific node status, go here.
There are several points where it is possible to connect into the Intermountain Intertie via IRLP or even "I-Link" - but most of these are through other systems whereby a radio may be remotely controlled to connect to an Intermountain Intertie repeater.
IRLP Node 3660, however, is intended to provide a direct connection into the Hidden Peak hub repeater. It should be noted that although the computer hardware is present, it is not on the air! That is, even if you connect to it, you are talking to nothing - as no radio has been connected... yet. This continues to be an ongoing project.
If you have any questions about this node, please contact John Lloyd, K7JL.
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This page was last updated on 20150813
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