[wxqc] Wireless Vantage Pro transmission drops

[Jack Jones]

Rex & Steve,

The wireless ISS sends a data packet to the console every 2 to 3 seconds 
regardless of the upload time interval selected.  However, as I said before, 
it appears the luthium battery is under charged.  It could be due to 
insufficient sunlight striking the solar panel or just a bad battery.

I realize Davis recommends orienting the solar panel to the south, but, in 
my location, with the summer sun rising in the NE & setting in the WNW, the 
rain collector shields the solar panel from direct sunlight.  Granted, it 
took over a year for my lithium battery to go to low voltage under those 
conditions but since I aimed the solar panel west, I haven't had any 
problems.  My outside unit sits in an open area with the closest shading 
structure 200' away.  However, if one is located where there are lots of 
trees & structures close by, it could severely restrict the amount of 
sunlight available to keep the battery charged.

Jack
----- Original Message ----- 
From: "Rex Pirkle" <pirkle at texoma.net>
To: <wxqc at lists.gladstonefamily.net>
Sent: Monday, August 15, 2005 10:00 PM
Subject: [wxqc] Wireless Vantage Pro transmission drops


>
> Steve,
> I would replace the Lithium battery and see if that resolves your
> problem.  You have your station set to post on a one-minute interval,
> and that places the highest possible demand on the transmitter battery.
> Lithium batteries are only good for about 300-500 charge discharge
> cycles, and develop a series resistance over time.  At 1-min transmit
> interval, yours gets the smallest possible chance to recharge, and my
> guess is that it stays undercharged.
>
> I think CWOP MesoNet only uses one data packet every 15 mins, so you
> might consider increasing your data interval to 5, 10, or 15 min to
> conserve transmitter battery power and extend the battery life. Davis
> says the lithium battery is good for 8 mo (without sunlight) up to 2
> years, but they don't say at what transmit interval that rating is
> measured.
>
> Radio Shack has a $15.50 battery checker that will test 3V Lithium
> batteries under a 1mA load. Catalog #: 22-080.
>
> Davis instructions says to point the solar cell to the South in the
> Northern Hemisphere.  That sense to me for the winter months and
> continuous daylight charging.  There is an AC power jack input on my
> wireless VP2 transmitter, but I couldn't find any Davis accessories to
> hard wire it, nor any reference to the use of that.  You might quiz
> Davis about it.
>
> If the battery is not the problem, check the console diagnostic screens
> detailed in the console manual.  That data will get you some clues about
> the reception problem, and will tell you if the station console battery
> is low.  The problem can be in the receiver as well as the transmitter.
> The VP2 has option to increase the transmitter gain, I do not know if
> you have that option not on a VP.
>
> VP2 transmits within 902 to 928 Mhz FHSS.  I have 900Mhz phones that a
> microwave interferes with, but the VP2 spread spectrum seems to have
> good immunity from RF sources and interference.  Try changing your
> station ID switches to a different setting if you think there is some
> local source interfering with the transmissions.  Check your antenna
> orientations too; both vertical if at the same height, and with as few
> obstructions between them as possible.
>
> Rex K8CYJ-5 AR863
>
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