Cool Amateur Website.

Click on the logo to go to the main site.

 

 

Very nice site illustrating a very cool multi-repeater set up.

Click on the picture below to go to their picture gallery.

 

Local Coverage Maps

A few months ago, I put up an article concerning some software that would generate coverage maps given a site's coordinates and elevation.  It works in conjunction with NASA radar terrain maps of the Earth and seems to be pretty accurate.

(Article Link HERE. )

 

Anyway, football season was in full-swing so I promptly forgot about it during my 60 and 70 hour weeks.  Last night I finally sat down and figured out how to get it to work.  The maps below are my first attempt using the software (free to download, btw) and judging from what I've seen it so, I'm only scratching the surface of it's capabilities.  They say a picture is worth a thousand words...

 

 

Below is a screen capture of the general area generated in Google Maps to aid in locating towns. The NASA terrain data contains no landmarks in the final output except for detail on the topo map itself.  Click on any picture to see it at full resolution.

Area Map from Google

 

First, i decided to use an existing site to judge if the coverage map agreed with what I have experienced using the repeaters located there.  I decided the best comparison would be to compare the 442.325 repeater with the 443.950 repeater. 

The .325 antenna is approx 12 Dbi and is located at 3000 feet.  The .950 antenna is approx 5 Dbi and is located about 70 feet lower on the tower.  The .325 is running at approx 75 watts output while the .950 is running at approx 15 watts.  Below are the respective coverage maps - which seem to represent the different coverage areas accurately for each. 

The .325 coverage map

 

The .950 coverage map

 

Given the differences in output power, antenna gain, and antenna height, the coverage maps seem to be consistent with real-world performance.  Later in the week, I plan on generating coverage maps for the existing 220 machine and hypothetical 2 meter and 6 meter machines.

 

The next step was to apply this to the proposed River Hill Site which is currently in the planning stages (the repeater components are 99% together awaiting a few cables and the EPROM for the remote base interface.)

The initial power for the UHF repeater will be ten watts.  If the power can be increased without detriment to our host's UHF telemetry links, then that will be looked into. 

 

Proposed River Hill UHF Repeater Coverage Map (10 Dbi antenna @ 10 watts)

 

Detail of UHF coverage @ 10 watts

 

Wide view of UHF coverage @ 50 watts

 

Remote base 2 meter coverage.  Notice the enhanced coverage @ VHF even with a less efficient antenna.  The 2 meter remote base will provide better coverage into the southern and western areas of Claiborne County at lower power.

 

While the River Hill Site is mostly redundant to coverage that is enjoyed by .325 or could be gained by .950, the physical security of the site and thus the ability to pursue battery back-up and possible solar charging solutions make it worth the effort.  By enabling the River Hill repeater with frequency agile remote base/link radios which are DTMF controllable, it can easily be linked temporarily to any wide coverage repeater in the area on 2 meters, 220, or 440.

 

Steve, W4HKL

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A few more Maps

 

White Oak.

Here is the coverage pattern for the 220Mhz repeater.  I went with 10 watts output into a 7 Dbi antenna to get this...  I'm not sure of the actual output of the repeater, antenna, etc, but this map seems to match the coverage I get from the repeater.

 

Here is the coverage map for a 144 Mhz repeater running 50 watts into a 10 Dbi antenna.

 

Finally, here's the coverage map for a 6 meter "repeater" (read remote base) running 25 watts into a 10 Dbi antenna.  I should have reduced the antenna gain by at least half...  but you get the picture.

 

 

Speedwell (Clairfield Fire Dept. Tower)

Speedwell is an interesting site.  Little Pinnacle pretty screens -off  Middlesboro and the Gap...  but the coverage across Claiborne County is pretty good considering.

10 watts and 5 Dbi mobile whip do pretty good.

 

Leaving it at 10 watts but switching to a decent 10 Dbi base antenna really increases saturation.

 

What the heck...  add a 100 watt Mirage amp inline and you get this.  Nice...  but not as much an improvement as you might think.

 

 

CUGA - aka the Pinnacle

The Park Service has a UHF repeater not far from the Pinnacle Overlook.  I was able to get pretty close using the NASA topo data...  here's what the program predicts.

Here's 10 watts into a 5 Dbi mobile whip.  Stealth might be an issue since it's the Park...  Not bad coverage for Claiborne Co.  Note how the Speedwell site is comparable.

 

This is 10 watts with a 10 Dbi antenna. 

 

Putting 100 watts into the mix seems to help outlying regions more than anything else.

 

Cumberland Gap (my QTH)

Here's 35 watts UHF into an 8 Dbi antenna from "the Hole."  Never bitch about my signal again.  Nuff said.

 

 

**note

I'll get coverage maps up for other repeaters if I can get GPS coordnates and approx heights...  Pineville would be especially nice to have.  Maps I plan on generating are:

2 meter Pineville

10 meter split site repeater (White Oak / Pineville)

Local Repeater News

 

August 3, 2008

The 442.325 (+) (T 100 Hz) Middlesboro Repeater should be back on the air by late next week.  The Jonesville Virginia machine, 442.575 (+) (T100 Hz), should also be up and running as well. The 443.950 machine will come down for several weeks to have it's tone board installed (T 100Hz) and have the two cooling fans mounted to the power amplifier heatsink.  The 950 machine will go back up for more testing at a later date but don't forget to add the 100 Hertz tone when it does!

 

Also, please remember the Pinevile 146.835 (+ PLUS OFFSET) (Tone 100Hz) is up and on the air and is providing good local coverage for Bell County, Kentucky.  If you need a repeater to get you from Middlesboro to Pinevile and as far North as Corbin...  or perhaps fromPine3ville to Harlan... then the .835 is what you need.

 

 

Below is the 443.950 backup repeater and it's duplexer.  The HT is shown for scale.

Another shot of the .950 - "the little repeater that could!"

Steve, W4HKL

Field Day 2008

Below are some pictures from the MARC Field Day for 2008.

 

KI4QIS and NM4H

 

One of several wire antennas placed with the help of KF4GXQ's launcher.

 

W4TEY makes a contact.

 

Another antenna!

 

W2RAR and N4TOF sadly inform new ham Aaron, KJ4DFQ, that he must be at least "this tall" to participate in Field Day!

 

W2RAR looks on.

 

N4TOF and his flip-up shades.

 

The operating position of W2RAR and NX6R.

 

The operating position of W4HKL.

 

W4HKL.  "CQ Repeater!"

 

Hamstick Dipole on the bottom (80 or 40 meters) with a separate 20 thru 10 meter vertical whip on the top.  W4HKL's "Appalachian Buddipole" or the "HillbillyPole."

 

Apologies to WC4V, KF4GXQ, and NX6R for not getting them in any shots.  Next year, guys!

 

- W4HKL

Coverage Maps

I've got to head out, but here's a link to a site that allows you to use hi-res Nasa radar topo imagery to create signal coverage maps of your area.  More later, but here's a quick sample:

 Radio Mobile Freeware by VE2DBE

 

 

 

 

The KF4JVI Solar Powered Repeater

The KF4JVI Solar Powered Repeater in Polk County, NC is pretty much a prototype of what I'd like to do with the 443.950 repeater with regard to the power system.  After looking at their very nice web page, I was impressed.

 

The KF4JVI Solar Powered Repeater

 

New Low-Profile 440 Repeater On The Air

Ed, Yeary, W4TEY, is currently hosting the W4HKL 443.950 repeater (positive offset - no tone) atop his tower for the time being. 

 

The repeater consists of a GE Mastr Exec II converted by Henry Hamblin, WB4IVB.  My advice, if you are looking for a clean repeater build that works right the first time, is to contact Henry and see when he could build up a repeater to your specs. 

The W4HKL repeater consists of components similar to the ones pictured below:

GE Mastr Exec II Mobile Repeater Prior To Conversion

Duplexers Similar To The Ones Used On 443.95

 

I'll have pics up of the actual finished setup when I get everything mounted in it's travel case.  the 443.950 repeater is meant to provide HT quality coverage for most of North Claiborne County with the addition of Middlesboro and Rose Hill, VA as well.  Coverage is approximately from Speedwell to Rose Hill... and from the Pilot north of Middlesboro to just south of Dogwood Heights (before heading down the hill into Tazewell.

Battery backup is planned in the upcoming months. 

It is hoped that a site covering the majority of Claiborne County will eventually be located... or that a second repeater can be linked to 443.950 which will provide combined county-wide coverage.  Should a suitable site in Claiborne Co. not be available, the repeater may become coordinated for White Oak Mountain in Middlesboro Kentucky - perhaps using a pair of phased Yagis to deliver more concentrated coverage into North Claiborne County and Powell Valley. 

Testing of this repeater has commenced on 5/29/08.  Initially, the repeater will be turned of between the approximate hours of 11:30 pm and 8:00 am until a dedicated repeater antenna can be mounted which will hopefully eliminate the current disruption of W4TEY's nightime scanner listening!

 

W4HKL

Fresh From WC4V Labs...

Radio/antenna setup for W4HKL repeater from WC4V QTH

 

Submitted by Stephen Vaughn, WC4V

The Ultimate Backup Power Solution...?

But will it fit in Mike's truck so we can get it up on White Oak???

 

The Hyperion Power Generation "nuclear battery" is a self contained, automated, liquid metal nuclear reactor.

 

 

What Kind Of Antennas To Use On Field Day?

What kind of antennas do YOU plan to hoist skyward in the wee hours of June 28?