Re: Antenna connection issue - GPSMap 76CS




"Ed" <edATridersiteDOTorg> wrote in message
news:mvGdnSnk7IwzBkjYnZ2dnUVZ_rWnnZ2d@xxxxxxxxxxxxxx
I'm not knowledgeable enough to do what you suggest - electronics is one
of my many shortcomings. However, I asked Garmin about the problem and
they said to send in the GPSR and they would fix it under warranty. Thus,
it seems as if they may have encountered this issue before.

Furthermore, I have used this setup extensively for a year without issue.
Given all the circumstances, it seems most likely to be a connection
problem.

I cleaned the connectors, tried to slightly decreased the diameter of the
female connector (with a small knife) and threaded the cable through the
battery compartment D-ring as Dave Wetmore suggested. This seems to have
helped considerably. I took it out for a 4-mile walk and had no problems
with satellite lock.

I will send it to Garmin on Tuesday (plan to use it this weekend). I'll
report back if Garmin notes anything of significance.

Ed Hass

John Bonde wrote:
It's possible it is the antenna. Garmin external antennas are designed
to work down to 2 volts. The Gilsson's specs say ~2.5 volts minimum.
I don't have a Gilsson, but the thing to do would be to check the
voltage provided to the antenna from the Garmin 76CS under load.
Yes, you would have to make some kind of adapter, but if the voltage
is less than ~2.25 the antenna may just be starved for voltage. I don't
know how tolerant the Gilsson is to low voltage.

I had this happen with a GPSMAP76 and an aftermarket 2.5 volt
antenna. It would occasionally loose sats when left on for days.
Sometimes I got 24 hours of good data, sometimes maybe 1 hour
in 24 was bad. If I were using the combo for short periods of time
the symptoms would be just like a loose connection. To track
down the problem I checked the voltage provided to the antenna
and it was 2.1 volts. A few emails to the manufacturer confirmed
that this was too low. ~2.25 volts would have been OK, but at
2.1 volts you would expect some problems.

This was replicated on 3 receivers and two antennas. Many
days of data recording later with a Garmin (2 volt) antenna showed
no problems.

The CS and/or Gilsson may be different, but it's something to
think about.

Ed wrote:

Since I got my 76CS, I?ve used it extensively with a Gilsson antenna
(for hiking, x-country skiing and bicycling) and it has worked
beautifully. However, recently it has started to lose its lock on
satellites when using the antenna. It seems that there is some sort of
issue where the antenna connects to the GPSR. I've tried three
different Gilsson antennas (all with right angle cable connectors) and
the problem persists, so I?m pretty sure it is not simply the antenna.
I can turn the connected cable a little and recover the satellite lock,
but a few minutes later it will loose the lock again ? so it definitely
seems to be at the connector. Has anyone else had this problem when
using a powered antenna? I really like the way the 76CS works with an
antenna because it enables me to do many activities hands free with the
76CS in a pocket - which also keeps the batteries warmer than when left
out in the open.

Arthur Hass
Reston, VA

I have to agree it is probably a connector problem. I have used two Gilsson
external antennas with my 76CS for years with no problems.


.



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