[W2] Waterproofing the sensor

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[W2] Waterproofing the sensor

M0XDF
Reposting this since I haven't seen a reply, which is unusual for this list.

I'd be interested to hear from anyone who has waterproofed a W2 sensor, I'm considering the W2 and want to put the sensor on the masthead.
73 de David, M0XDF (K3 #174, P3 #108)
--
Experience is that marvellous thing that enables you to recognize a mistake when you make it again. -Franklin P. Jones

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Re: [W2] Waterproofing the sensor

GM4KGK
David
Can't help you with waterproofing the W2 sensor (short of suggesting a
separate enclosure), but if you are still looking for a W2 I have a
pristine example with the 2kw HF sensor and all the leads. Now redundant
as the KPA500 power and SWR metering is more than adequate for my needs.
Contact me off list -  norman at gm4kgk dot co dot uk
73
Norman - GM4KGK

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Re: [W2] Waterproofing the sensor

Bill K9YEQ
In reply to this post by M0XDF
I will watch for the response as well.   I would rather have the unit near
the base where I tune.

73,
Bill
K9YEQ

-----Original Message-----
Reposting this since I haven't seen a reply, which is unusual for this list.

I'd be interested to hear from anyone who has waterproofed a W2 sensor, I'm
considering the W2 and want to put the sensor on the masthead.
73 de David, M0XDF (K3 #174, P3 #108)

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Re: [W2] Waterproofing the sensor

M0XDF
Ok, GM3SEK would have something to say on waterproofing - like it's almost impossible and since there will be air in the box, and temp variations (I'm putting it on the masthead remember), then that will cause worse corrosion, so better to leave a very small hole to allow it to breath. Getting the kind of box you mention Ron is no problem, Tesco sell them here and I had that in mind.

Now if I can get a vent with a muslin type cover, that would stop the spiders. I wonder if I can make one while a ordinary cable gland, a very small holed washer and some material?

Next problem - how long can the UTP be?

73 de David, M0XDF (K3 #174, P3 #108)
--
Natural ability without education has more often attained to glory and virtue than education without natural ability. -Cicero, statesman, orator, writer (106-43 BC)

On 27 Jan 2012, at 22:26, Ron D'Eau Claire wrote:

> Keeping something outdoors dry isn't a big issue. An plastic food container
> will keep it dry. Just be sure to arrange the exit points for the cables so
> they are pointing downward to prevent rain from running down a wire into the
> enclosure.
>
> I've not remoted a W2 sensor, but have used that technique on many matching
> networks.
>
> But that leaves two other issues:
>
> 1) If the unit is not totally sealed you'll get tiny bugs inside it -
> including the famous pin-head size spiders that are so adept at shorting out
> antenna traps. Unless you'll be checking and cleaning it regularly, I'd
> carefully caulk the openings for the cables so the box is absolutely sealed
> and use a container with a good seal on the lid. One of the types of
> water-tight containers that has a rubber o-ring seal around the lid is best.
> They are available in the USA for under $5 in the size you'd need. (If you
> buy a "Snap-Loc" brand container, it's made here in the USA too :-)
>
> 2) Has anyone tried really long runs of the sensor cable to see how the
> system behaves, especially in a strong RF field? I don't know of a spec for
> the maximum cable run for the sensor wire.
>
> 73,
>
> Ron AC7AC
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Bill K9YEQ
> Sent: Friday, January 27, 2012 1:55 PM
> To: 'David Ferrington, M0XDF'; [hidden email]
> Subject: Re: [Elecraft] [W2] Waterproofing the sensor
>
> I will watch for the response as well.   I would rather have the unit near
> the base where I tune.
>
> 73,
> Bill
> K9YEQ
>
> -----Original Message-----
> Reposting this since I haven't seen a reply, which is unusual for this list.
>
> I'd be interested to hear from anyone who has waterproofed a W2 sensor, I'm
> considering the W2 and want to put the sensor on the masthead.
> 73 de David, M0XDF (K3 #174, P3 #108)
>
> ______________________________________________________________
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Re: [W2] Waterproofing the sensor

Don Wilhelm-4
In reply to this post by Bill K9YEQ
Ron,

There are 2 philosophies on those containers - one is to totally seal
them as you have suggested, and the other is to put a drain hole at the
bottom to drain condensation out.

For a totally sealed container, it all depends on the moisture content
of the air when it was sealed, and the current ambient temperature.

Here in the North Carolina Summer, we can have humidity levels of 98%
along with temperatures of 100+ degF.  If an enclosure is sealed under
those conditions, and then the ambient temperature drops, there will be
a lot of moisture condensing in that box.  Simple laws of physics
prevail, while hot air can contain that amount of moisture, when the
temperature drops, it will "rain in the enclosure".

I don't have an absolute answer to the seal or leave a drain hole
question, but if it is sealed, be certain to seal it in times of lowest
humidity and the lowest temperature to keep the amount of moisture
inside the container to a minimum.

73,
Don W3FPR

On 1/27/2012 5:26 PM, Ron D'Eau Claire wrote:

> Keeping something outdoors dry isn't a big issue. An plastic food container
> will keep it dry. Just be sure to arrange the exit points for the cables so
> they are pointing downward to prevent rain from running down a wire into the
> enclosure.
>
> I've not remoted a W2 sensor, but have used that technique on many matching
> networks.
>
> But that leaves two other issues:
>
> 1) If the unit is not totally sealed you'll get tiny bugs inside it -
> including the famous pin-head size spiders that are so adept at shorting out
> antenna traps. Unless you'll be checking and cleaning it regularly, I'd
> carefully caulk the openings for the cables so the box is absolutely sealed
> and use a container with a good seal on the lid. One of the types of
> water-tight containers that has a rubber o-ring seal around the lid is best.
> They are available in the USA for under $5 in the size you'd need. (If you
> buy a "Snap-Loc" brand container, it's made here in the USA too :-)
>
> 2) Has anyone tried really long runs of the sensor cable to see how the
> system behaves, especially in a strong RF field? I don't know of a spec for
> the maximum cable run for the sensor wire.
>
> 73,
>
> Ron AC7AC
>
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Re: [W2] Waterproofing the sensor

David Christ
If you want to seal it, throw in a handful of Silica Gel packets
first.  They come packed in everything these days so should you
should be able scrounge them for free.  That should help prevent
condensation.

David K0LUM


At 5:51 PM -0500 1/27/12, Don Wilhelm wrote:

>Ron,
>
>There are 2 philosophies on those containers - one is to totally seal
>them as you have suggested, and the other is to put a drain hole at the
>bottom to drain condensation out.
>
>For a totally sealed container, it all depends on the moisture content
>of the air when it was sealed, and the current ambient temperature.
>
>Here in the North Carolina Summer, we can have humidity levels of 98%
>along with temperatures of 100+ degF.  If an enclosure is sealed under
>those conditions, and then the ambient temperature drops, there will be
>a lot of moisture condensing in that box.  Simple laws of physics
>prevail, while hot air can contain that amount of moisture, when the
>temperature drops, it will "rain in the enclosure".
>
>I don't have an absolute answer to the seal or leave a drain hole
>question, but if it is sealed, be certain to seal it in times of lowest
>humidity and the lowest temperature to keep the amount of moisture
>inside the container to a minimum.
>
>73,
>Don W3FPR
>
>On 1/27/2012 5:26 PM, Ron D'Eau Claire wrote:
>>  Keeping something outdoors dry isn't a big issue. An plastic food container
>>  will keep it dry. Just be sure to arrange the exit points for the cables so
>>  they are pointing downward to prevent rain from running down a wire into the
>>  enclosure.
>>
>>  I've not remoted a W2 sensor, but have used that technique on many matching
>>  networks.
>>
>>  But that leaves two other issues:
>>
>>  1) If the unit is not totally sealed you'll get tiny bugs inside it -
>>  including the famous pin-head size spiders that are so adept at shorting out
>>  antenna traps. Unless you'll be checking and cleaning it regularly, I'd
>>  carefully caulk the openings for the cables so the box is absolutely sealed
>>  and use a container with a good seal on the lid. One of the types of
>>  water-tight containers that has a rubber o-ring seal around the lid is best.
>>  They are available in the USA for under $5 in the size you'd need. (If you
>>  buy a "Snap-Loc" brand container, it's made here in the USA too :-)
>>
>>  2) Has anyone tried really long runs of the sensor cable to see how the
>>  system behaves, especially in a strong RF field? I don't know of a spec for
>>  the maximum cable run for the sensor wire.
>>
>>  73,
>>
>>  Ron AC7AC
>>
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Re: [W2] Waterproofing the sensor

Bill K9YEQ
In reply to this post by Bill K9YEQ
Understood, and same advice I would give so it seems the moving the device
outdoors does involve separate container.

73,
Bill
K9YEQ
----Original Message-----

Keeping something outdoors dry isn't a big issue. An plastic food container
will keep it dry. Just be sure to arrange the exit points for the cables so
they are pointing downward to prevent rain from running down a wire into the
enclosure.

I've not remoted a W2 sensor, but have used that technique on many matching
networks.

But that leaves two other issues:

1) If the unit is not totally sealed you'll get tiny bugs inside it -
including the famous pin-head size spiders that are so adept at shorting out
antenna traps. Unless you'll be checking and cleaning it regularly, I'd
carefully caulk the openings for the cables so the box is absolutely sealed
and use a container with a good seal on the lid. One of the types of
water-tight containers that has a rubber o-ring seal around the lid is best.
They are available in the USA for under $5 in the size you'd need. (If you
buy a "Snap-Loc" brand container, it's made here in the USA too :-)

2) Has anyone tried really long runs of the sensor cable to see how the
system behaves, especially in a strong RF field? I don't know of a spec for
the maximum cable run for the sensor wire.

73,

Ron AC7AC

-----Original Message-----

I will watch for the response as well.   I would rather have the unit near
the base where I tune.

73,
Bill
K9YEQ

-----Original Message-----
Reposting this since I haven't seen a reply, which is unusual for this list.

I'd be interested to hear from anyone who has waterproofed a W2 sensor, I'm
considering the W2 and want to put the sensor on the masthead.
73 de David, M0XDF (K3 #174, P3 #108)


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Re: [W2] Waterproofing the sensor

Bill K9YEQ
In reply to this post by Don Wilhelm-4
I agree as long as the packets are dryer than what the lowest outdoor temp
will be.  

73,
Bill
K9YEQ


-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Don Wilhelm

Ron,

There are 2 philosophies on those containers - one is to totally seal them
as you have suggested, and the other is to put a drain hole at the bottom to
drain condensation out.

For a totally sealed container, it all depends on the moisture content of
the air when it was sealed, and the current ambient temperature.

Here in the North Carolina Summer, we can have humidity levels of 98% along
with temperatures of 100+ degF.  If an enclosure is sealed under those
conditions, and then the ambient temperature drops, there will be a lot of
moisture condensing in that box.  Simple laws of physics prevail, while hot
air can contain that amount of moisture, when the temperature drops, it will
"rain in the enclosure".

I don't have an absolute answer to the seal or leave a drain hole question,
but if it is sealed, be certain to seal it in times of lowest humidity and
the lowest temperature to keep the amount of moisture inside the container
to a minimum.

73,
Don W3FPR

On 1/27/2012 5:26 PM, Ron D'Eau Claire wrote:

> Keeping something outdoors dry isn't a big issue. An plastic food
> container will keep it dry. Just be sure to arrange the exit points
> for the cables so they are pointing downward to prevent rain from
> running down a wire into the enclosure.
>
> I've not remoted a W2 sensor, but have used that technique on many
> matching networks.
>
> But that leaves two other issues:
>
> 1) If the unit is not totally sealed you'll get tiny bugs inside it -
> including the famous pin-head size spiders that are so adept at
> shorting out antenna traps. Unless you'll be checking and cleaning it
> regularly, I'd carefully caulk the openings for the cables so the box
> is absolutely sealed and use a container with a good seal on the lid.
> One of the types of water-tight containers that has a rubber o-ring seal
around the lid is best.

> They are available in the USA for under $5 in the size you'd need. (If
> you buy a "Snap-Loc" brand container, it's made here in the USA too
> :-)
>
> 2) Has anyone tried really long runs of the sensor cable to see how
> the system behaves, especially in a strong RF field? I don't know of a
> spec for the maximum cable run for the sensor wire.
>
> 73,
>
> Ron AC7AC
>

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Re: [W2] Waterproofing the sensor

Bill K9YEQ
In reply to this post by David Christ
I followed the link to confirm... note the heated Desiccant needs to go into
a sealed container warm.  Amazing to see this stuff sent with so much stuff
that isn't sealed.  What a waste and a hazard.

73,
Bill
K9YEQ


-----Original Message-----


Yep. That's what we do on ships where an outside enclosure experiences huge
swings in temperature in a very humid salt air environment.

If you are re-using packets, throw them in your oven on WARM for an hour to
regenerate them.

And you can get new desiccant on line for a few bucks (e.g.
http://www.drierite.com/default.htm )

The weep hole approach works FB too for most installations as long as one
realizes that teeny-tiny critters will make their home inside so you need to
clean it out from time to time.

Ron AC7AC

-----Original Message-----

If you want to seal it, throw in a handful of Silica Gel packets first.
They come packed in everything these days so should you should be able
scrounge them for free.  That should help prevent condensation.

David K0LUM


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Re: [W2] Waterproofing the sensor

Mike WA8BXN
In reply to this post by Bill K9YEQ

 
Its not clear to me why one would need to put the sense element at the
antenna. About the only benefit to it that I can see is you can make sure
your coax to that point has not become extremely lossy. Just about anything
else can be measured with the sensor in the shack. One would be more
interested in knowing the SWR looking into the feedline at the transmitter
than at the antenna end.
 
If an automatic antenna tuner is near the antenna feed point, if its working
then the SWR should be low in the coax from the tuner to the rig. Trying to
read the SWR between a tuner and antenna is not all that useful and many swr
sensors may not be accurate when not used in 50 ohm feedlines. I didn't
quite say that right. Between a tuner and antenna we would expect a high swr
and the feedline not matching the Z of the antenna. If the antenna is
resonant, then a tuner would not be needed.
 
So I am missing something, perhaps someone could fill me in!
 
73/72 - Mike WA8BXN
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Re: [W2] Waterproofing the sensor

k6dgw
In reply to this post by M0XDF
You can put it in a "waterproof" box [I've used plastic boxes for
matching networks at the tower].  It's like a "waterproof watch" -- not
really waterproof, just somewhat resistant.  And, the water doesn't
always come from outside.

For a sealed box, if the temp ever falls below the dew point when you
sealed the box, water will condense inside the box.  You can put drying
agents inside the box to reduce this, be careful, they suck water out of
the air very fast  If they came from packing they're probably already
full of it.  I have a little "pillow" in a plastic jar for my hearing
aids with silica gel under it to dry them out at night.  About once a
week, I have to nuke it for 30 secs and put it back in the jar warm.

Every "water resistant" enclosure we had in SE Asia had a drain hole [it
actually does get cold enough in Vietnam to condense at night around
December :-)].  I've put things in plastic boxes, made sure water
couldn't run into it [it runs downhill - drip loops], and left a hole in
the bottom.  After a few years, they don't exhibit water damage when I
just look at them.  I'm at 38 deg N, your mileage may vary.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2012 Cal QSO Party 6-7 Oct 2012
- www.cqp.org

On 1/27/2012 7:28 AM, David Ferrington, M0XDF wrote:
> Reposting this since I haven't seen a reply, which is unusual for this list.


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Re: [W2] Waterproofing the sensor

Bill K9YEQ
Fred,  

I agree with your comments.  The only issue is the small spiders and the
damage they can inflict.  I lost a trail camera due to spider droppings.
Amazing the damage given a few years and the very super small openings they
used.

I want the remote to determine SWR at the remote tuner which I use.  In the
shack I get a reading which is not the same on the tuner at the remote.  I
would like a remote before the tuner so I know what is coming back to the
shack.  The K3 can tell me the SWR going out but it does not consider the
coax interaction.  The THP HL-2.5Kfx is picky!  :-)

73,
Bill
K9YEQ


-----Original Message-----

You can put it in a "waterproof" box [I've used plastic boxes for matching
networks at the tower].  It's like a "waterproof watch" -- not really
waterproof, just somewhat resistant.  And, the water doesn't always come
from outside.

For a sealed box, if the temp ever falls below the dew point when you sealed
the box, water will condense inside the box.  You can put drying agents
inside the box to reduce this, be careful, they suck water out of the air
very fast  If they came from packing they're probably already full of it.  I
have a little "pillow" in a plastic jar for my hearing aids with silica gel
under it to dry them out at night.  About once a week, I have to nuke it for
30 secs and put it back in the jar warm.

Every "water resistant" enclosure we had in SE Asia had a drain hole [it
actually does get cold enough in Vietnam to condense at night around
December :-)].  I've put things in plastic boxes, made sure water couldn't
run into it [it runs downhill - drip loops], and left a hole in the bottom.
After a few years, they don't exhibit water damage when I just look at them.
I'm at 38 deg N, your mileage may vary.

73,

Fred K6DGW

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Re: [W2] Waterproofing the sensor

Mike WA8BXN
Hi Bill -

Unless you are putting the amplifier remotely out with the tuner, then you
really don't so much care what the SWR reading is at the tuner in the coax
going to the shack. What you are more interested in is what the amplifier (I
assume in your shack) will see looking into the coax going to the
tuner/antenna system.
 
You might try putting say 6 feet of coax from your K3 to the W2 sensor and
see how the swr looks there (in about the place in the coax the amplifier
might be). I suspect there may be some difference in readings. Next step is
to determine/understand why.
 
73 - Mike WA8BXN
 
 
 
 
-------Original Message-------
 
From: Bill K9YEQ
Date: 1/27/2012 8:29:05 PM
To: [hidden email]; [hidden email]
Subject: Re: [Elecraft] [W2] Waterproofing the sensor
 
Fred,
 
I agree with your comments. The only issue is the small spiders and the
Damage they can inflict. I lost a trail camera due to spider droppings.
Amazing the damage given a few years and the very super small openings they
Used.
 
I want the remote to determine SWR at the remote tuner which I use. In the
Shack I get a reading which is not the same on the tuner at the remote. I
Would like a remote before the tuner so I know what is coming back to the
Shack. The K3 can tell me the SWR going out but it does not consider the
Coax interaction. The THP HL-2.5Kfx is picky! :-)
 
73,
Bill
K9YEQ
 
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Re: [W2] Waterproofing the sensor

M0XDF
In reply to this post by Mike WA8BXN
This will be a 2M sensor, about 10m from the PA and just before a preamp, connected to a 17 ele Tonna.
The preamp can handle 150W and the contests I'm interested in have a 'restricted' section for 100W max, so I want to ensure I'm not pushing more 100W into the pre-amp, which with losses I guess could be 110-120 PEP at the amp.

Not two worried about SWR at the amp and I have a simple MJF the I can use to measure that in the shack.

Plus I'm considering options to 'A-B' switch sensors if I have more than 2.

I'm also feeding an SGC to a long wire, which is remote by approx. 30m and considering putting a remote HF sensor down there. This is fed direct from the K3/100 in Bypass mode, so SWR readable on the rig.

73 de David, M0XDF (K3 #174, P3 #108)
--
Any hound a porcupine nudges, Can't be blamed for harboring grudges.
I know one hound that laughed all winter, At a porcupine that sat on a splinter.                                                
- Ogden Nash (1902-1971)

On 28 Jan 2012, at 00:50, Mike WA8BXN wrote:

>
>
> Its not clear to me why one would need to put the sense element at the
> antenna. About the only benefit to it that I can see is you can make sure
> your coax to that point has not become extremely lossy. Just about anything
> else can be measured with the sensor in the shack. One would be more
> interested in knowing the SWR looking into the feedline at the transmitter
> than at the antenna end.
>
> If an automatic antenna tuner is near the antenna feed point, if its working
> then the SWR should be low in the coax from the tuner to the rig. Trying to
> read the SWR between a tuner and antenna is not all that useful and many swr
> sensors may not be accurate when not used in 50 ohm feedlines. I didn't
> quite say that right. Between a tuner and antenna we would expect a high swr
> and the feedline not matching the Z of the antenna. If the antenna is
> resonant, then a tuner would not be needed.
>
> So I am missing something, perhaps someone could fill me in!
>
> 73/72 - Mike WA8BXN
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Re: [W2] Waterproofing the sensor

Gary Hinson
In reply to this post by M0XDF
Hi David.

I haven't waterproofed the sensor head but I did experiment with a ~30m long
Ethernet cable to see whether I could locate a second sensor at my remote
antenna switch plus the one near the rig, to check the feeder loss.  It
didn't work out.  Looking at the schematics, I think there are resistors in
the lines inside the sensor box that might be worth bypassing to see if I
can get enough signal back for a realistic reading, but I ran out of play
time before being able to try that.

73
Gary  ZL2iFB

> -----Original Message-----
> From: [hidden email] [mailto:elecraft-
> [hidden email]] On Behalf Of David Ferrington, M0XDF
> Sent: Saturday, 28 January 2012 4:28 a.m.
> To: [hidden email]
> Subject: [Elecraft] [W2] Waterproofing the sensor
>
> Reposting this since I haven't seen a reply, which is unusual for this
list.
>
> I'd be interested to hear from anyone who has waterproofed a W2 sensor,
> I'm considering the W2 and want to put the sensor on the masthead.
> 73 de David, M0XDF (K3 #174, P3 #108)
> --
> Experience is that marvellous thing that enables you to recognize a
mistake

> when you make it again. -Franklin P. Jones
>
> __________________________________________________________
> ____
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Re: [W2] Waterproofing the sensor

M0XDF
Very useful info Gary - so 'remote' is'nt quite so remote as I had in mind :-(.

could anyone who has gone more that a few feet reply with how far they have gone with it reliably working please?
73 de David, M0XDF (K3 #174, P3 #108)
--
I really hate this damn machine, I wish that they would sell it.
It never does just what I want, but only what I tell it!

On 28 Jan 2012, at 08:36, Gary Hinson wrote:

> Hi David.
>
> I haven't waterproofed the sensor head but I did experiment with a ~30m long
> Ethernet cable to see whether I could locate a second sensor at my remote
> antenna switch plus the one near the rig, to check the feeder loss.  It
> didn't work out.  Looking at the schematics, I think there are resistors in
> the lines inside the sensor box that might be worth bypassing to see if I
> can get enough signal back for a realistic reading, but I ran out of play
> time before being able to try that.

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Re: [W2] Waterproofing the sensor

Bill K9YEQ
In reply to this post by Gary Hinson
Good to know.  Thanks!!

73,
Bill
K9YEQ


-----Original Message-----


Hi David.

I haven't waterproofed the sensor head but I did experiment with a ~30m long
Ethernet cable to see whether I could locate a second sensor at my remote
antenna switch plus the one near the rig, to check the feeder loss.  It
didn't work out.  Looking at the schematics, I think there are resistors in
the lines inside the sensor box that might be worth bypassing to see if I
can get enough signal back for a realistic reading, but I ran out of play
time before being able to try that.

73
Gary  ZL2iFB

> -----Original Message-----
 
> Reposting this since I haven't seen a reply, which is unusual for this
list.
>
> I'd be interested to hear from anyone who has waterproofed a W2
> sensor, I'm considering the W2 and want to put the sensor on the masthead.
> 73 de David, M0XDF (K3 #174, P3 #108)
> --

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Re: [W2] Waterproofing the sensor

Bill K9YEQ
In reply to this post by M0XDF
I think I have at least a 50 footer I will try and report back soon, if I
can find it.  Perhaps Wayne  can give us some feedback.

73,
Bill
K9YEQ


-----Original Message-----


Very useful info Gary - so 'remote' is'nt quite so remote as I had in mind
:-(.

could anyone who has gone more that a few feet reply with how far they have
gone with it reliably working please?
73 de David, M0XDF (K3 #174, P3 #108)
--
I really hate this damn machine, I wish that they would sell it.
It never does just what I want, but only what I tell it!

On 28 Jan 2012, at 08:36, Gary Hinson wrote:

> Hi David.
>
> I haven't waterproofed the sensor head but I did experiment with a
> ~30m long Ethernet cable to see whether I could locate a second sensor
> at my remote antenna switch plus the one near the rig, to check the
> feeder loss.  It didn't work out.  Looking at the schematics, I think
> there are resistors in the lines inside the sensor box that might be
> worth bypassing to see if I can get enough signal back for a realistic
> reading, but I ran out of play time before being able to try that.


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