Len wrote:
Any thoughts on why a Uniden QT206 digital depth display fogs up to
the point of being unreadable? Has anyone else experienced this?

When the weather is warm and the cabin is open (twice this season, so
far, here in the Puget Sound area), the unit has cleared up and works
well. But as soon as there is any temperature difference between
inside and outside, the unit fogs to the point where it is completely
unreadable, and will eventually fail to operate.

I replaced the first unit with a second after calling Uniden and being
told the unit was defective and would be repaired. But the next one
did exactly the same thing. Originally purchased based on the
strength of a Practical Sailor review ('03, I believe).

I only need a digital depth meter, not anything more fancy. The shoot-
through-the-hull option of the QT206 was also attractive for my solid
glass hull sailboat.

In a followup e-mail to Uniden, I was told basically "sorry it doesn't
work. Get your money back from your retailer." They didn't offer to
repair the new 2 1/8" hole in my boat, however.

This can't be an entirely isolated incident. Has anyone had success
sealing a gauge from the back (this one sticks into the galley
cabinet) to defeat what appears to be a design deficiency?

Thanks,
Leonard
s/v "Meeresstille"

I had a similar experience with a JRC 1500 radar LCD display which I
returned to Seattle for out of warranty service. JRC smeared ski goggle
"Cat Crap" cream on the inside of the glass which may have helped
marginally. I built a clip on heated 12v cowled fan to blow 48 watts of
warm air on the outside of the glass surface, seemed to work June 1 in
fog banks crossing Juan de Fuca strait.
Dick

Any thoughts on why a Uniden QT206 digital depth display fogs up to
the point of being unreadable? Has anyone else experienced this?

When the weather is warm and the cabin is open (twice this season, so
far, here in the Puget Sound area), the unit has cleared up and works
well. But as soon as there is any temperature difference between
inside and outside, the unit fogs to the point where it is completely
unreadable, and will eventually fail to operate.

I replaced the first unit with a second after calling Uniden and being
told the unit was defective and would be repaired. But the next one
did exactly the same thing. Originally purchased based on the
strength of a Practical Sailor review ('03, I believe).

I only need a digital depth meter, not anything more fancy. The shoot-
through-the-hull option of the QT206 was also attractive for my solid
glass hull sailboat.

In a followup e-mail to Uniden, I was told basically "sorry it doesn't
work. Get your money back from your retailer." They didn't offer to
repair the new 2 1/8" hole in my boat, however.

This can't be an entirely isolated incident. Has anyone had success
sealing a gauge from the back (this one sticks into the galley
cabinet) to defeat what appears to be a design deficiency?

Thanks,
Leonard
s/v "Meeresstille"

One trick that Raytheon suggests is to keep the backlight on day and night.
This should drive the humidity out of the case.

Caitzu

"Len" wrote in message
ups.com...
Any thoughts on why a Uniden QT206 digital depth display fogs up to
the point of being unreadable? Has anyone else experienced this?

When the weather is warm and the cabin is open (twice this season, so
far, here in the Puget Sound area), the unit has cleared up and works
well. But as soon as there is any temperature difference between
inside and outside, the unit fogs to the point where it is completely
unreadable, and will eventually fail to operate.

I replaced the first unit with a second after calling Uniden and being
told the unit was defective and would be repaired. But the next one
did exactly the same thing. Originally purchased based on the
strength of a Practical Sailor review ('03, I believe).

I only need a digital depth meter, not anything more fancy. The shoot-
through-the-hull option of the QT206 was also attractive for my solid
glass hull sailboat.

In a followup e-mail to Uniden, I was told basically "sorry it doesn't
work. Get your money back from your retailer." They didn't offer to
repair the new 2 1/8" hole in my boat, however.

This can't be an entirely isolated incident. Has anyone had success
sealing a gauge from the back (this one sticks into the galley
cabinet) to defeat what appears to be a design deficiency?

Thanks,
Leonard
s/v "Meeresstille"

Jack Erbes wrote:
Len wrote:
Any thoughts on why a Uniden QT206 digital depth display fogs up to
the point of being unreadable? Has anyone else experienced this?
snip

The case has to be vented to allow for expansion when everything warms
up. As it cools down, it pulls moisture laden air into the case and
that condenses inside the unit. Next warm up cycle, the air expands,
then the moisture is warmed up and condenses on the glass and
components. But there is not enough air movement to push the moisture
out so from that point on, the moisture is there to stay, it just cycles
back and forth and the amount can slowly increase inside the unit.

Some marine units used to be sealed and nitrogen filled and that worked
okay for a year or two but it was really impractical to maintain the
seal with controls, card slots, etc.

Some models used things like small silica gel ("Do Not Eat") packs
inside and the moisture would collect in those. I'm not sure it was
much help because they could warm up and could cook the moisture out of
the silica gel.

The only real cure is to open the case and drive all the air and
moisture out with warm (not hot) dry air. Several hours with a gentle
warm plow from a hair dryer or heat gun will do it. Do it at home or in
the shop, cool it slowly and close it back up in a dry place.

This can't be an entirely isolated incident. Has anyone had success
sealing a gauge from the back (this one sticks into the galley
cabinet) to defeat what appears to be a design deficiency?

That sounds like a dry but open to the atmosphere location. You might
try putting a loose fitting bag around the back of the instrument. Snip
a corner off to run the leads in, use rigging tape to seal the bag to
the housing. That small amount of dead air space may buffer the heating
and cooling cycles enough to prevent or at least slow the moisture
buildup.

If the font of the instrument is not well sealed and/or the instrument
is not mounted on a thin bead of silicone, the moisture may be getting
in from the front. There is not much hope for curing the problem with a
poorly sealed housing.

Jack.




Thanks,
Leonard
s/v "Meeresstille"



Jack,
The JRC radar display has two GoreTex patches over breather holes which
keep out liquid water but I am sure permit passage of water vapor laden
air. I only mount the display on the binnacle if I anticipate needing radar.
Dick
Nonsuch 26, Swoose

Len wrote:
Any thoughts on why a Uniden QT206 digital depth display fogs up to
the point of being unreadable? Has anyone else experienced this?
snip

The case has to be vented to allow for expansion when everything warms
up. As it cools down, it pulls moisture laden air into the case and
that condenses inside the unit. Next warm up cycle, the air expands,
then the moisture is warmed up and condenses on the glass and
components. But there is not enough air movement to push the moisture
out so from that point on, the moisture is there to stay, it just cycles
back and forth and the amount can slowly increase inside the unit.

Some marine units used to be sealed and nitrogen filled and that worked
okay for a year or two but it was really impractical to maintain the
seal with controls, card slots, etc.

Some models used things like small silica gel ("Do Not Eat") packs
inside and the moisture would collect in those. I'm not sure it was
much help because they could warm up and could cook the moisture out of
the silica gel.

The only real cure is to open the case and drive all the air and
moisture out with warm (not hot) dry air. Several hours with a gentle
warm plow from a hair dryer or heat gun will do it. Do it at home or in
the shop, cool it slowly and close it back up in a dry place.

This can't be an entirely isolated incident. Has anyone had success
sealing a gauge from the back (this one sticks into the galley
cabinet) to defeat what appears to be a design deficiency?

That sounds like a dry but open to the atmosphere location. You might
try putting a loose fitting bag around the back of the instrument. Snip
a corner off to run the leads in, use rigging tape to seal the bag to
the housing. That small amount of dead air space may buffer the heating
and cooling cycles enough to prevent or at least slow the moisture
buildup.

If the font of the instrument is not well sealed and/or the instrument
is not mounted on a thin bead of silicone, the moisture may be getting
in from the front. There is not much hope for curing the problem with a
poorly sealed housing.

Jack.




Thanks,
Leonard
s/v "Meeresstille"



--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Richard Lane wrote:
snip
Jack,
The JRC radar display has two GoreTex patches over breather holes which
keep out liquid water but I am sure permit passage of water vapor laden
air. I only mount the display on the binnacle if I anticipate needing
radar.
Dick
Nonsuch 26, Swoose

Interesting concept. I'm not sure if that can work or not. I find a
web site that explains GoreTex:

http://www.gore-tex.com/remote/Satel...Frameset/index

and it has two statements that sort of contradict each other:

"The microporous structure of the GORE-TEX® membrane is what makes
GORE-TEX® fabrics completely waterproof. Each microscopic pore is about
20,000 times smaller than a drop of water, which means no external
moisture - from rain to snow to that puddle you just stepped in - can
penetrate the membrane."

"What makes GORE-TEX® products so breathable? The pores in the GORE-TEX®
membrane are 700 times bigger than a water vapor molecule, so
perspiration can easily evaporate through and you can stay dry from the
inside out. Breathability is an important component of comfort when you
are active."

So as I understand that description, drops of water can not get in but
molecules of water vapor from moisture laden air could be drawn in as
the unit cooled. So you still would have the same issues, no?

As an aside, I helped move a Hatteras 50 motor yacht from Florida to
Maryland a few years ago. It was named Swoose in memory of a B-17
bomber that had been named after a WW II-era song "Alexander The
Swoose." More details about it he

http://www.nasm.si.edu/research/aero...oeing_b17d.htm

Jack