At 01:55 PM 2008-05-09 -0600, Paul Plack wrote:
Why DTMF controlled? If the batteries run down because no one starts the generator, you'll be unable to start it remotely, and have to go to the site. Use a repeater controller which has enough smarts to monitor the system, start and stop the generator automatically, page someone when there's a problem, and provide a DTMF override of the automatic functions if needed.
I'm not at all sure if that's a good enough solution. Which is why I'm asking. Also if we see the batteries are getting down a bit but that the forecast is for five days of sunshine then there is no need to run the generator. So I'm not sure I want an automatic solution. I also realize that the more you use the batteries and the lower you drain them the shorter the battery life. That is draining a battery right down once shortens a battery life much more than draining a battery 1% 100 times.
How secure is your site? A generator and fuel supply could be attractive resale opportunities for meth addicts. Then again, so might solar panels or a wind turbine.
It's reasonably remote. At least an hours drive from the nearest city. Ten minutes from the nearest town. Lots of gravel roads which won't deter such but this hasn't been a problem out in rural Alberta.
You haven't mentioned how your site is laid out, or how much space you have, but wind may be a good alternative. If you determine a realistic power budget, you might be surprised at how small a wind turbine would keep the site up. With enough reserve battery capacity and a repeater controller programmed to load-shed by reducing power when things get tight, much can be done. A few months ago, I looked into small turbines, and found one designed for portable use by motor home owners. It had blades about 1.3m in diameter, and IIRC would be capable of 200+ watts continuous in a 15 mph wind.
My initial posting mentions that the owner of the tower felt that the land owner wouldn't like another wind turbine on the site.
The MSR2000 may not be the best candidate for alternative power, since its idle current draw will be significant, and reducing transmitter power will not produce a proportionate drop in current consumption. I'd guess the GMR300s also have relatively high idle current.
Yes, we're looking at that as well. One suggestion was to look at Daniels MT-2 Series repeaters. Not sure what would be suitable alternatives for the UHF linking radios but we'll consider all suggestions. <smile>
Interesting ideas snipped.
But, alas, FM land mobile users don't like weak signal work, and I eventually bit the bullet and went to a GE Mastr II and AC power. You may also find, as others are suggesting, that commercial AC mains with battery backup is the most cost-effective option in a practical system.
This will be the only repeater covering a fair bit of the terrain with some overlap at the edges. I'm not quite sure just how much difference 5 watts output vs 100 watts will make. I'll let the other guy who understands the modelling a lot better than I do generate the coverage maps. And about half the activity is due to mobile users such as truckers as this repeater covers a chunk of a major highway.
Tony
