[TowerTalk] Wind Gauges: Summary
John Scott, VE1JS
scotts@tartannet.ns.ca
Wed, 19 Jan 2000 13:51:24 +0000
Many thanks to all who replied to my query about RF getting into the
electronics of so called Weather Stations.
There seem to be two major manufacturers
Peet Brothers.
www.peetbros.com/index.html
and
Davis Instruments
www.davisnet.com
Both make/sell a number of different models.
Both sites contain a lot of information which needs to be sifted carefully.
Davis mentions a "protected" junction box which is supposed to help with
'static discharge, radio frequency interference, and voltage surges' You
replace the standard junction box with this one at a cost of about
$US65.00. This will work, I think with any of their models.
Comments from messages received seem to indicate that one pays one's money
and takes one's chance as far as RFI is conerned. Only person one reported
having actual damage to a display unit from RF. Naturally displays go
crazy in RF fields. But then, does that matter as long as you get an
accurate reading when you want it?
Some of the comments received:
N4ZR:
Mine -- A Davis Weather Wizard III -- goes ape when I transmit (ca. 1000
watts out) on some bands, but I haven't yet begun to apply any RFI
protection. Davis sells an RFI filter box that is designed to deal with
this problem, but like many of their accessories it is badly overpriced. I
plan RF chokes and bypassing as required.
=====
WA3AFS:
I use the Davis Weather Monitor II. I run up to 600 watts out. The
sensors are mounted about 20 feet away from the tribander and
about 20 feet away from one of the 80M and one of the 40M
verticals.
I have many ferrite beads on all the leads coming in to the display
box and once in a while I still get some 40M interference on the
barometric display (I also use the connection to a PC).
I am satisfied once I added all the beads.
=====
N0SS:
My most recent experiences (about 8-10 years ago) were HORRID!
LOTS of RFI into the display unit and it finally TOASTED the display
unit... even with in-line chokes.
=====
VE1RX:
I have a Davis Weatehr Wizard 111. I do get RF back into it and does
change the temperatures or wind speed briefly but then resets itself back
to the correct settings . 100 watts does not seem to bother it , but
anything over 300
does . I have had it for three years and have not seen anything long term
damage .
=====
WC1M:
Some weather stations restrict the length of the cable between the sensor
and the display. I use a Radio Shack weather station that restricts the
cable length to about 40 feet. It's a good unit (really made by Oregon (?)
Scientific), but the cable length restriction forced me to put the wind
sensor on the roof. I think the Peet units let you use cables of much longer
lengths. There are also units on the market that use and RF link. I think
Peet and Davis both have those. A friend who was using an older Davis unit
with a cable link said it was very susceptible to RFI and he had to purchase
a special filter kit. I'm pretty sure Peet has a web site.
=====
K1YP:
Fascinating Electronics also makes a high quality unit:
http://www.columbia-center.org/fascinating/obs/instrmnt.html
=========
KD5FDE:
I have an anamometer mounted at about 40 feet of a 55 ft tower.
Run 100 wats on HF into a 160 meter dipole fed at the top of the tower.
I also have a 2 mtr Vetical at the top of the tower. I have not
experienced any problems with the anamometer while transmitting at 100
watts HF or 50 watts vhf. HOWEVER..I have a temp and humidity sensor at
the 6 ft level of the tower and when I transmit on hf the display for
temp and humidity show dashed lines on my display...it recovers quickly
when I stop transmitting (almost instantly). The unit is an Oregon
Scientific unit. Sensors feed the indoor unit by wire. I don't think
you will have any problems with your wind guage readings mounting the
sensors on the tower. Hope this helps.
P.S. the anamometer is grounded to the tower.
========
WE9V:
I bought the Peet Bros one at Dayton this year.
I put the anamometer (wind thingie) at the top of my 100' tower.
The included cable was about 40'. I added, oh, about 200' to
that with cheap 4 conductor, non-shielded telephone wire. It's
run in the same conduit as my RG-8 cables (80/160M) and right next
to my CATV (10-40M) runs. I also use the tower as a shunt-fed
vertical on 160M. I run 1500W on all HF bands, all modes.
I've never had any RFI problems with the display unit or the readings.
Also, the Peet Bros unit only restricts the length of the outdoor
temp sensor, not the wind unit, as they are seperate sensors. The
wind sensor is just contact closures, whereas the temperature is
dependant upon resistance, and adding long conductors will add
resistance, thereby changing the "temperature".
========
W8GAZ:
I have the Peet Bros weather station with the wind anamonitor just below my
Force 12 EF320 @ 51 ft. no problems at all. I'm running 500 watts. I have a
Force 12 4BA 10 ft higher up which covers 18-10m. The Tower is about 100 ft
from the shack. I have the temp sensor and rain gauge mouted near the
ground. The display is right in the shack. I hope this helps.
=======
So, there you have it. I have not made any decisions yet. I still want to
check out the Fascinating web site to see what they have. I have the added
problem of importing such things into Canada and the somewhat anemic
Canadian dollar. I do know of a couple of places in Canada that sell both
Davis and Peet Bros stuff.
There's no hurry. I'm not climbing anything till the snow goes away and
the temperature rises a bit, in spite of what coventional Amateur wisdom
says about doing antenna/tower work at this time of the year!!
Thanks again to all who replied.
John, VE1JS
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