In article ,
wrote:

On Sun, 13 Dec 2009 23:48:25 -0500, Wayne.B
wrote:

On Sun, 13 Dec 2009 15:14:31 -0500, "Flying Pig"
wrote:

I'll try to find someone with a SWR meter here tomorrow morning before we
head out to our anchorage prior to going into the dock where we'll be
leaving Flying Pig, and give it a whirl.

One of the quirks of waterlogged coax is that it can exhibit a perfect
1:1 SWR ratio while transmitting little or no power because the signal
loss is so high that nothing gets reflected back to the SWR meter.

I also have the little cable and the mast-top antenna which proved the cable
at fault in the original explorations; it will be easy for me to get a boat
buddy to listen while I read some story or something on a remote channel and
see if that cured it. That shortie, BTW, is LMR400, so should be fine for
the test. I don't expect it's got much in the way of SWR issues :{))


OK

As to sagging power, with an 880AH bank, I doubt that's a problem,

Agreed but you could have a bad connection which is heating up under
load.

Accurate SWR measurements also require clear dry conditions. An
overcast day will affect the readings.

Bull****..... I don't know where you got your learning, but you should
go back and ask for a REFUND...because you are talking thru your HAT....

I have been in the business for 40+ Years, and my Bird Wattmeter reads
the same at VHF Frequencies, in the Fog, or under then Baking Sun....

--
Bruce in alaska
add path after fast to reply

In article ,
cavelamb wrote:



What Wayne said...

From what I've seen of "professional" work (unless you did it yourself and
know), it would be worth checking.

I think this whole discussion ,is just about as funny a thread ,as I
have read, in months. If you don't have the right tools, and know what
you are doing, you just "****ing into the Wind"...

Yes, there are a few "Professionals" around who don't have Clue One, and
there are some that can't afford to buy the "Correct Tools" to do the
job.

If you want a real Marine Radioman, you need to pay for his Knowledge,
Service, and his Test Equipment.... or you can stumble around and learn
it yourself, after much Trial and Error.....

SaltyDog isn't even close to being a REAL Marine Radioman..... and his
attempt to sidetrack the discussion, by introducing a Trivial, and for
all Practical Purposes, irrelevant factor into the thread, is so silly
as to show a lack of intelligence in the field.

Oh well, folks can believe what they will, but it doesn't change the
FACTS... and the issues at hand.... Wilbur, Well we all know about
Wilbur... Enough said on that front....

--
Bruce in alaska
add path after fast to reply

On Mon, 14 Dec 2009 15:23:42 -0500, wrote:

Boy, somebody sure feels threatened.

I don't think you should take it personally. "Bruce in Alaska" has
more real world electronic experience, by far, than anyone else in
this group that I know of. I've been FCC licensed in one capacity or
another since 1957 and would defer to his judgement on just about
anything.

On Mon, 14 Dec 2009 15:39:49 -0500, Wayne.B
wrote:

On Mon, 14 Dec 2009 15:23:42 -0500, wrote:

Boy, somebody sure feels threatened.

I don't think you should take it personally. "Bruce in Alaska" has
more real world electronic experience, by far, than anyone else in
this group that I know of. I've been FCC licensed in one capacity or
another since 1957 and would defer to his judgement on just about
anything.

Bruce should give his opinion on the 214 versus the other cable
recently discussed. And whether mil spec means anything.
That's been questioned too, and I'm a bit confused.
Which is ok. Lucky for me I don't have a radio.

--Vic

On 14/12/2009 19:06, wrote:
On Mon, 14 Dec 2009 18:51:00 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 18:33, wrote:
On Mon, 14 Dec 2009 18:30:49 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 18:24, wrote:
On Mon, 14 Dec 2009 17:50:24 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 17:48, wrote:
On Mon, 14 Dec 2009 17:33:33 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 15:28, wrote:
On Mon, 14 Dec 2009 15:15:48 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 11:00, wrote:
On Sun, 13 Dec 2009 23:48:25 -0500, Wayne.B
wrote:

On Sun, 13 Dec 2009 15:14:31 -0500, "Flying Pig"
wrote:

I'll try to find someone with a SWR meter here tomorrow morning before we
head out to our anchorage prior to going into the dock where we'll be
leaving Flying Pig, and give it a whirl.

One of the quirks of waterlogged coax is that it can exhibit a perfect
1:1 SWR ratio while transmitting little or no power because the signal
loss is so high that nothing gets reflected back to the SWR meter.

I also have the little cable and the mast-top antenna which proved the cable
at fault in the original explorations; it will be easy for me to get a boat
buddy to listen while I read some story or something on a remote channel and
see if that cured it. That shortie, BTW, is LMR400, so should be fine for
the test. I don't expect it's got much in the way of SWR issues :{))


OK

As to sagging power, with an 880AH bank, I doubt that's a problem,

Agreed but you could have a bad connection which is heating up under
load.

Accurate SWR measurements also require clear dry conditions. An
overcast day will affect the readings.

Probably a Ham's old wives' tale. Your average VSWR meter is not very
accurate, although still quite useful. This leads to all sorts of BS.
The device I use cost more than my boat..

Nope, not an old wives tale at all.


Work out the _magnitude_ of the change in electrical length of the
antenna due to water vapour for yourself.

http://www.kayelaby.npl.co.uk/genera...2_5/2_5_7.html



Oh, so you now acknowledge that it DOES make a difference... Okay!

Yes, but it is "**** all".


Here is what I said:

Accurate SWR measurements also require clear dry conditions. An
overcast day will affect the readings.

After much huffing, puffing and posturing, you now admit that
statement was absolutely correct.

Apology accepted.

Still not worked out how much the centre frequency shifts compared to
the typical 2Mhz bandwidth?

Hey, you were wrong. Man up and move on.

Ask someone to work it out for you..

Wussy!

It's about the same magnitude as shaving 2 thou off a 3ft. dipole, at
most, unless I made a mistake doing it in my head.. Besides, shouldn't
you tune for typical conditions not for Antarctica.

This link I came across might be of interest to some.
http://www.mike-willis.com/Tutorial/refraction.htm

"Bruce in alaska" wrote in message
...
In article s.com,
"Wilbur Hubbard" wrote:

"Wayne.B" wrote in message
...

Agreed but you could have a bad connection which is heating up under
load.



BINGO! They use one of those crap, 'slow burn' fuses. They heat up and
the
extra impedance reduces the voltage. Get rid of it and put a higher
amperage
rated, fast burn fuse in - end of problem.

Wilbur Hubbard

Bull****.... Wilbur, you need to stick to stuff you know about....
as Peter Bennett pointed out, if the volume at the receiver dropped, but
the background noise didn't change, then the problem is in the
Modulating Deviation, not the Power Output.... This is FM not AM or
SSB.... In FM, once you exceed 12 db of Receiver Quieting the
Background Noise, changes are hardly perceptible, and in FM, the volume
produced in the receiver is directly proportional to the Modulation
Deviation of the Transmitter, until it exceeds the bandwidth of the
Receiver.

--
Bruce in alaska
add path after fast to reply




You don't read too well, dude. Skippy said the volume of his 'transmission'
as heard by other listeners in nearby boats decreased noticeably after about
a minute.

So the problem is with Skippy's transmitter and not his receiver. If the
fuse heats up and the voltage drops and the "low voltage" indicator flashes
in the readout as Skippy indicated then that should tell you something. Duh!


Wilbur Hubbard

On Mon, 14 Dec 2009 21:24:55 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 19:06, wrote:
On Mon, 14 Dec 2009 18:51:00 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 18:33, wrote:
On Mon, 14 Dec 2009 18:30:49 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 18:24, wrote:
On Mon, 14 Dec 2009 17:50:24 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 17:48, wrote:
On Mon, 14 Dec 2009 17:33:33 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 15:28, wrote:
On Mon, 14 Dec 2009 15:15:48 +0000, goofball_star_dot_etal
wrote:

On 14/12/2009 11:00, wrote:
On Sun, 13 Dec 2009 23:48:25 -0500, Wayne.B
wrote:

On Sun, 13 Dec 2009 15:14:31 -0500, "Flying Pig"
wrote:

I'll try to find someone with a SWR meter here tomorrow morning before we
head out to our anchorage prior to going into the dock where we'll be
leaving Flying Pig, and give it a whirl.

One of the quirks of waterlogged coax is that it can exhibit a perfect
1:1 SWR ratio while transmitting little or no power because the signal
loss is so high that nothing gets reflected back to the SWR meter.

I also have the little cable and the mast-top antenna which proved the cable
at fault in the original explorations; it will be easy for me to get a boat
buddy to listen while I read some story or something on a remote channel and
see if that cured it. That shortie, BTW, is LMR400, so should be fine for
the test. I don't expect it's got much in the way of SWR issues :{))


OK

As to sagging power, with an 880AH bank, I doubt that's a problem,

Agreed but you could have a bad connection which is heating up under
load.

Accurate SWR measurements also require clear dry conditions. An
overcast day will affect the readings.

Probably a Ham's old wives' tale. Your average VSWR meter is not very
accurate, although still quite useful. This leads to all sorts of BS.
The device I use cost more than my boat..

Nope, not an old wives tale at all.


Work out the _magnitude_ of the change in electrical length of the
antenna due to water vapour for yourself.

http://www.kayelaby.npl.co.uk/genera...2_5/2_5_7.html



Oh, so you now acknowledge that it DOES make a difference... Okay!

Yes, but it is "**** all".


Here is what I said:

Accurate SWR measurements also require clear dry conditions. An
overcast day will affect the readings.

After much huffing, puffing and posturing, you now admit that
statement was absolutely correct.

Apology accepted.

Still not worked out how much the centre frequency shifts compared to
the typical 2Mhz bandwidth?

Hey, you were wrong. Man up and move on.

Ask someone to work it out for you..

Wussy!

It's about the same magnitude as shaving 2 thou off a 3ft. dipole, at
most, unless I made a mistake doing it in my head.. Besides, shouldn't
you tune for typical conditions not for Antarctica.

This link I came across might be of interest to some.
http://www.mike-willis.com/Tutorial/refraction.htm


WIMP!

On 13/12/2009 20:14, Flying Pig wrote:


it will be easy for me to get a boat
buddy to listen while I read some story or something on a remote channel

Are you sure someone didn't just doze off last time you tried?

In article ,
Vic Smith wrote:

On Mon, 14 Dec 2009 15:39:49 -0500, Wayne.B
wrote:

On Mon, 14 Dec 2009 15:23:42 -0500, wrote:

Boy, somebody sure feels threatened.

I don't think you should take it personally. "Bruce in Alaska" has
more real world electronic experience, by far, than anyone else in
this group that I know of. I've been FCC licensed in one capacity or
another since 1957 and would defer to his judgement on just about
anything.

Bruce should give his opinion on the 214 versus the other cable
recently discussed. And whether mil spec means anything.
That's been questioned too, and I'm a bit confused.
Which is ok. Lucky for me I don't have a radio.

--Vic

Well, it would seem from all the previous posts that there is some
controversy about the recommended RF Coax for VHF Marine Installations
on various Vessel type.... Hmmmm... Well the answers are fairly
straight forward. It really depends on the installation. Small coax,
RG58 types, are alright for runs less than 10 Ft. For runs up 100Ft, RG8
Types Should be used. RG213 is better than RG8 or RG8 Foam Core Types,
due to Wx survivability, and Water Intrusion. The Price Difference
between RG213 and RG214, is usually NOT a cost effective for a NORMAL
Marine Installation, especially on a non-Commercial Vessels, where
budgets are tight. For Military Installations RG214 is the MINIMUM. On
commercial vessels up thru the 80's, RG213 was the standard, for runs
under 100 Ft. Then the newer coax types became available, like Belden
9913 & 9914. These were touted as the Poor Man's Heliax, and looking at
the Specs back then, they were. They are iffy for Marine Use, mostly
because of Bending Radius Specs, AND 9913 is a Hollow Core Type, so any
water intrusion issues ruins the cable. The LMR Stuff around NOW is
similar to the Beldon stuff, and has the same issues in that some is
Hollow Core and it has limitations in Bending Radiuses. For Runs longer
than 100 Ft. Heliax was the only thing used, in the Old Days. Modern
replacements have come along in the 80's and 90's that are better on
Price with similar Specs. In all this the Installation is the CRITICAL
Factor, NOT the coax type used. Water Tight Fittings and Connectors,
and getting the connectors INSTALLED CORRECTLY, is far more important
than 213 vs 214 issues. I kind of doubt that many of the folks that read
this Group even know how to install a PL-259 correctly. If you can do it
in less than three minutes, you don't have a clue. 99% of Vhf Antenna
System failures are do to installation issues, or CHEAP Antennas.

If your paying someone to look at you stuff, and he brings anything
aboard to check the VHF Antennas other than a Bird Wattmeter with the
appropriate Slugs, kick them off your boat as if they had Homeric Fever,
because they are Dufus's and will only cost you money. If you take your
radio to a Service Shop and the guy Doesn't have a Real Service Monitor,
Do NOT have them work on you rig. They are hacks and don't deserve your
business. Even IF these folks show up with ALL the Right Tools, that
doesn't mean they know what is what, it only means the have the Tools.
Watch them like a hawk. Ask Questions. Experience Shows, and any Good
Radioman will be more than happy to explain what he is doing and why,
AND will show you exactly what your problem IS and what it will take to
correct it.

I was always willing to show my customers everything they wanted to know
about their stuff, because they learned, and I didn't have to fix the
same stuff twice, for the same guy. I always had more business than I
could work, and I usually sent the Apprentice's down on the small stuff,
after they had worked with me, for six months, out in the field. I have
trained a lot of Marine Techs, over the years, and as we are a Dying
Breed, Many are doing other things in RF Communications than Marine work
these days. I used to be able to count the Quality Marine Radiomen on
the West Coast and North Pacific on two hands. NOW it is down to One
hand, and MF/HF Marine RadioMen... well I can think if just (4) that I
would take my rigs to, as this is now a Very Specialized Area of Marine
World, and mostly obsolete, due to TracPhones, Cellular, and GMDSS.
I am just happy to consult and be semi-reTired.

--
Bruce in alaska
add path after fast to reply

Wayne.B wrote:
On Mon, 14 Dec 2009 11:57:59 -0600, brian whatcott
wrote:

it is not all that easy to maintain a 50 ohm impedance AND soak up
most of the transmit power with salt water in a coax

If the coax is soaking most of the transmit power it doesn't really
matter what impeadance it is. An SWR meter will still show no
reflected power, hence a 1:1 ratio.


Hmmm.. that sounds a little doubtful to me. If a coax gets a short,
it reflects plenty before the short. If a coax gets an open, it
reflects plenty before the open.... If a coax gets a 50 ohm lossy
resistance, then it soaks up all the power with no reflection.

That's where I'm coming from...

B