Re: [scoutradio] Digest Number 81
- Alan, when they say that it will run for two days with no sun, they mean NO
sun. And that is at a 50% duty cycle. We don't anticipate either situation
occuring. The worst case situation is that a load of snow and ice gets on the
panels, which will reduce, but not cut off the sun. At our northern latitude the
panels are pitched up at a pretty steep angle, so snow is unlikely to stick.
Ice might. We plan to put a low battery alarm on the repeater - it will beep
each time the repeater is keyed up. If a temporary low-sun-low battery
condition were to occur, the rangers have a small portable generator that could
be used to charge the batteries, but according to the folks at SunWize who
designed the system, the odds of ever needing to do this are extremely remote.
Also, usage in the winter months will be minimal. Weekdays there are only two
rangers on duty, and they mostly work side by side.
Wind turbines are expensive and require maintenance - even the best ones. I
have many years of experience with them, from Jacobs and Enertech to DOE/NASA
Mod IIa (250kw). For a mere thousand dollars, I can double the number of solar
panels and not have to worry about them.
The rangers won't have to do much about monitoring the system. If the
repeater's performance suffers a bit, they will call me and I will take either a
gator or a snow machine up the hill to check. This is a commercial (MstrII)
repeater in excellent condition, and we expect no trouble. It is a very simple
Three of my Scouts may be on the air from our club's field day operation at
W1FN. I will be there on Sunday, because I will be changing the Scout
reservation's repeater antenna and feedline on Saturday.
YIS & 73
Dave Colter WA1ZCN
> Date: Tue, 20 Jun 2000 13:32:43 -0400
> From: "Alan Stumpf" <aws69@...>
> Subject: Equipment
> Are you going to add a small gas generator up there or are the rangers going
> to have to switch out the batteries if there is no sun for 2 days. Also how
> about adding a new wind turbine, they are very efficient and have many
> safety overrides that keep the speed down.
> Also how will the rangers keep an eye out on how the equipment is working?
> How about adding a APRS Station with telemetry?
> Is anyone doing any scout related stuff at Field Day?
> Alan Stumpf, KB3DHC
> Assistant Scoutmaster Troop 377
> Greater Pittsburgh Council
> Enda Lechauhanne 57 | >>===>===> |
> 3rd Assistant Scoutmaster 2001 Jamboree Troop RED (No number yet)
> North Hills Amateur Radio Club
> JOTA Committee Chair
> > The repeater sits on a 3000+' remote mountaintop out in the
> > reservation's back-country. The reservation is >5 square miles of
> > mountainous terrain with five lakes and ponds, and it is a winding,
> > almost five mile drive from the ranger's HQ to the summit. The repeater
> > (GE Mastr II) was powered by a windmill and a homebrew gasoline driven
> > 12v generator that charged a bunch of really old used 200 amp bus
> > batteries. Someone had to hike up (no Gator then!) every few days to
> > run the generator for a few hours, since the wind wasn't reliable
> > enough, and winter ice and winds tore the blades off the windmill. That
> > wore pretty thin after one season, and they pulled the system off the
> > hill and put it at the ranger's HQ on a 80' tower - the lowest point in
> > camp, and at the southern-most tip of the reservation. Coverage was
> > pretty poor from there, especially out in the northern back-country.
> > Last summer we began planning a return to the mountain, this time with
> > solar power. On Sunday, after a winter of planning and preparation, I
> > took the reservation's new John Deere Gator up the mountain (a 45 minute
> > bone-jouncing ride from HQ) and installed two new Siemens 100 watt
> > panels on the side of the old windmill tower. Next trip we will string
> > a new support cable and some #8UF cable to the fiberglass equipment
> > shelter which will house the MII repeater, solar charger/controller and
> > new deep cycle "bus" batteries. By design, the solar system should
> > provide enough power for a 50% transmit duty cycle for two days without
> > sunlight. The cost of the solar system (plus cables and misc. parts)
> > was about $2300 from Tessco.