In article ,
"Lynn Coffelt" wrote:

"Bruce in Alaska" wrote in message
...
In article ,
"Lynn Coffelt" wrote:

Looking at the website, I notice they have whole new designed radomes
to
replace our crappy 2D domes that rain inside and rot the potmetal
guts.
Hope the new one is sealed up.

"Sealed up" being a theoretical state in the marine environment, of
course. Do the Raytheon open array antennas still have drain tubes to
sling
water "in case" there should be any "condensation"? Hmmmmm?
Got about 12 liters of water out of an 8 foot Krupp Atlas one time.
The
beautiful, almost new, 64 mile radar would only get echos from about
half a
mile.
A good "TR down" installation had one or more mica "dams" in the
waveguide to keep from having wet feet in the pilot house (or the
"void").
Old Chief Lynn



After that Krupp had run for a couple of weeks, all that water would
have been excited to steam and gone, if the Maggie lasted that long......

Bruce in alaska

Well, we did put in a 5kw 2J42 just to see what would happen (because
we were ill prepared, and that's what the tube kit had)...... but in a few
hours it just didn't ring very well at all. Bob ???, an old Radar Electric
guy taught me that the best tool in the kit was an earphone. You could tell
almost anything going on in a pulse maggie with such beauty and ease.
"Bob ???" had a reputation with Decca 050's and 101's almost as great
as "George" from Ketchikan. I owed Bob much of my livelihood for a few years
for his ability to teach me by telephone! He could play the guitar almost as
well as he could diagnose Decca Group 9's weird behaviors.
Old Chief Lynn (050's forever)



Yep, I remember Radar George in Ketchikan....he got married and left
town, and there hasn't been a good Radioman in Ketchikan since. He
also was a whizz on Wood Freeman AutoPilots, as well....

Bruce in alaska
--
add a 2 before @

Bruce in Alaska wrote in news:bruceg-
:

After that Krupp had run for a couple of weeks, all that water would
have been excited to steam and gone, if the Maggie lasted that
long......


In the 60's, aboard USS Everglades (AD-24), we were about 1/2 way across
the Atlantic headed for the wonderful Naples Sailor Resort when our
AN/SPS-21 Raytheon Pathfinder got more and more insensitive. It just
couldn't see a ship on the horizon we could see from the bridge below the
antenna!

I got hooked into finding the problem and when I pulled the waveguide off
the transceiver it looked like someone had flushed a toilet on the deck
of the little radar room. The waveguide leaked, bad. We found a joint
had been pulled apart, breaking the flange off the guide, not good.

Under the gun to get a picture back on the bridge, I went down to my cal
lab and reeled off a length of RG-213/U, some N connectors and stole a
couple of waveguide to coax adapters out of the cal lab microwave bench.
I put one adapter on the antenna and one on the transceiver then
tywrapped the 213 coax to the waveguide up the stick, about 35 ft to the
antenna base.

Holding my breath and praying it wouldn't arc madly, I flipped the
switch. Calling down to the bridge on the sound-powered phones, the RD
reported his image was perfect and he had a big target at 24 miles just
fine.

I think that coax was still on it when I was transferred off the ship a
year later....(c;

I never figured out why the Pathfinder didn't arc the little pin antennas
in the waveguide adapters, but it didn't. The old waveguide was all
eaten up inside from all the water in it. It must have been in there a
long time.

The best place I've found for learning how to connect the devices is the
manufacturers web sites. If one of the devices is a Garmin, read what you
can get first, then verify with Garmin. They answer email within 24 hours,
and make the instructions simple and easy to follow. Connecting a DSC
capable radio should be easy. A depth finder may not have NMEA capability. I
wired my GPS to both a radio and a radar by splicing the wires to go to both
devices. You can also make a bus bar as a distribution point, with screws to
connect the wires.
"luc" wrote in message
oups.com...
I am an NMEA neophyte. I am trying to connect my Raymarine speedo,
depth, and wind indicator. They use SeaTalk. Apparently, SeaTalk is
not NMEA language. I thought the point of NMEA was to make multiple
manufactures equipment communicate, much like MIDI (musical instrument
digital interface) works for electric guitars, keyboarsd, and
synthesizers.

I have a Garmin GPS, which does have some NMEA capabilities. I would
like to connect it to my ICom VHF, for the DSC feature. I would also
like to connect my sounder to the GPS to show depth on the Garmin. Is
this possible? Does anyone know where to get more information about
NMEA and connecting these various devices? I've already learned a bit,
but have a long way to go.

Also, from what I hear, the issue of "daisy chaining" is somewhat
resolved by the new NMEA 2000 protocol. Easy connectors, simple
wiring. Still, NMEA reminds me of DOS based computing. (it amazes me
that windows has DOS underlying it!)

I am sorry I bought my Ray Marine instruments that are not NMEA
compatible, if that's the word. Apparently, if I get a multiplexer, I
can make Sea Talk convert to NMEA. I'm sure all this junk is in it's
infancy, and one day will be resolved by some very cool technology.
It's already pretty cool, especially the Blue Tooth multiplexer made by
a company I don't know but recommended by someone on a google group.

anyone that cares to discuss this, I'm listening.

thanks

Luc

it's all pretty fubar, that's why it's hard to understand.

luc wrote:
I am an NMEA neophyte. I am trying to connect my Raymarine speedo,
depth, and wind indicator. They use SeaTalk. Apparently, SeaTalk is
not NMEA language. I thought the point of NMEA was to make multiple
manufactures equipment communicate, much like MIDI (musical instrument
digital interface) works for electric guitars, keyboarsd, and
synthesizers.

here's kind of the basics ...

NMEA ... depends on which standard you are talking about. there are
two, the NMEA 0183 standard which is a one way (one talker, many
listener) protocol for communicating GPS information from a GPS
receiver to one or more GPS data clients and a seperate NMEA 2000
protocol that is used for something more sophisticated. the NMEA 0183
protocol is sort of a language protocol, a series of text based
sentences, each one being a GPS fix, and the GPS receiver sends them
out on a periodic basis over 4800 baud. i don't think NMEA 0183 is a
hardware specification, however ... it's just a protocol, and it runs
over an rs-232 interface USUALLY, but it doesn't have to. it can also
be over USB, bluetooth, or whatever, the underlying hardware interface
as far as i know isn't specified. GPS receivers can put their GPS
information out on a serial cable in all kinds of formats, for example
my garmin i think has at least 10 different formats it can use. one of
those formats will be NMEA, usually, but some GPS receivers don't
support the NMEA format. that's all NMEA 0183, more about NMEA 2000
further down.

seatalk is a proprietary protocol and hardware specification created by
and for a manufacturer of marine equipment. it's not an open standard,
that is, as far as i know it's not published at all. it's kind of like
the ICOM CI-V protocol, it's just made by the manufacturer and they do
whatever they want with it to make their stuff work together. and they
charge a pretty penny to hook it all together, of course. seatalk is a
protocol that is used to transfer mostly sensor information such as
depth, wind speed, GPS information, etc, between instruments and
control equipment that talk it. at a hardware level it's also a
hardware spec which is basically rs-232 except that it's inverted ...
for god only knows what reason. a cynic might think they did it just
so it would be different than rs-232 and they could call it seatalk and
charge more, but i'm willing to give them the benefit of the doubt and
think they had a better reason.

NMEA 2000 is basically a network type of protocol like seatalk, except
it's an open standard that anyone can use. i haven't actually seen the
standard, but it's a protocol and a hardware specification, and i would
assume that it's very similar to rs-232 if not the exact same thing.
sort of the world's answer to a successful proprietary protocol when
the manufacturer is secretive and won't put out a specification for how
their stuff is hooked together. this is a bidirectional "networked"
type of protocol for transferring information like seatalk does around
different instruments and sensors.

I have a Garmin GPS, which does have some NMEA capabilities. I would
like to connect it to my ICom VHF, for the DSC feature. I would also
like to connect my sounder to the GPS to show depth on the Garmin. Is
this possible? Does anyone know where to get more information about
NMEA and connecting these various devices? I've already learned a bit,
but have a long way to go.

well, at a hardware level it's all pretty much rs-232, even seatalk
isn't that much different and can be converted, so you can learn a lot
about it just by reading about interfacing rs-232 devices together.
it's mostly just TX, RX, and ground wire(s), with sufficient attention
being paid to RF interference. at a software level i.e. the
communications protocol, that's a different animal altogether and
depends totally on what you are doing.

Also, from what I hear, the issue of "daisy chaining" is somewhat
resolved by the new NMEA 2000 protocol. Easy connectors, simple
wiring. Still, NMEA reminds me of DOS based computing. (it amazes me
that windows has DOS underlying it!)

if you mean it's very basic, it is, it's certainly not ethernet or
something like that. but you'd want it to be pretty basic. the
instruments aren't transferring very complicated data, it's all just
sensor readings and things. rs-232 is great for a lot of reasons, one
is that it's understood by a great many people, and another is that
it's fairly simple. it's also strong over longer cable lengths, easy
to interface to and make devices for, etc, and it's not that hard to
keep it from picking up distracting amounts of RF noise. so though it
isn't the most sophisticated way of doing things, maybe, it is pretty
hard to destroy and relatively easy to fix with available wiring.

in terms of development, rs-232 is much better than something
sophisticated like ethernet for these low bandwidth applications.
rs-232 is very simple and interfaces for it are even included in things
like PIC processors, very simple devices that are inexpensive to buy
and use. but as soon as you start wanting to talk ethernet then you're
talking about a TCP/IP stack, much higher bus speeds, some kind of a
basic operating system (typically), etc, you're going up a level in
sophistication and price. and you're also adding in a lot of potential
for failure as those devices get more sophisticated. there's something
to be said for being able to just grab some dumb terminal off the shelf
from like 1960 and hook it to your serial cable and see data coming
across it.

I am sorry I bought my Ray Marine instruments that are not NMEA
compatible, if that's the word. Apparently, if I get a multiplexer, I
can make Sea Talk convert to NMEA. I'm sure all this junk is in it's
infancy, and one day will be resolved by some very cool technology.
It's already pretty cool, especially the Blue Tooth multiplexer made by
a company I don't know but recommended by someone on a google group.

anyone that cares to discuss this, I'm listening.

thanks

Luc

"purple_stars" wrote in message
oups.com...
it's all pretty fubar, that's why it's hard to understand.

That is obvous...

With all respect Luc, but you're mixing things up very badly in your attempt
to explain things.
I'll comment between the lines:

The NMEA 0183 protocol is sort of a language protocol, a series of text
based
sentences, each one being a GPS fix, and the GPS receiver sends them
out on a periodic basis over 4800 baud. i don't think NMEA 0183 is a
hardware specification, however ... it's just a protocol, and it runs
over an rs-232 interface USUALLY

No. NMEA 0183 is a protocol AND a hardware specification, which exactly
specifies the voltage levels and the number of interface wires too. The
hardware side is the same as RS-422.
Any device with an RS232 port is not compliant with the NMEA-0183 standard
and is as such even forbidden on commercial vessels sailing under SOLAS
rules.

A GPS with an RS-232 interface will output NMEa formatted sentences but it
is stricktly speaking not an NMEA interface. The problem is that many
manufacturers choose to deviate from the standard in order to make a cheap
computer interface.

Seatalk is a proprietary protocol and hardware specification created by
and for a manufacturer of marine equipment.

Seatalk is a hardware AND a protocol (messages) specification which is
completely different from NMEA and RS-232 or RS-422. It is a one-wire
multiple-access collision detect protocol and indeed proprietary.

it's not an open standard,
that is, as far as i know it's not published at all. it's kind of like
the ICOM CI-V protocol, it's just made by the manufacturer and they do
whatever they want with it to make their stuff work together. and they
charge a pretty penny to hook it all together, of course. seatalk is a
protocol that is used to transfer mostly sensor information such as
depth, wind speed, GPS information, etc, between instruments and
control equipment that talk it. at a hardware level it's also a
hardware spec which is basically rs-232 except that it's inverted ...

Not at all. The only resemblence with "RS-232" is that it is serial data.
RS-232 is no protocol spec either, it just specifies the signals and their
levels on a connector. And an RS-232 link is meant to be a point-to-point
connection between two devices only.
Seatalk works on different levels AND it has 9 bits per byte while your
ordinary serial computer port can only handle 8 bits per byte (there are
some unreliable workarounds...).

for god only knows what reason. a cynic might think they did it just
so it would be different than rs-232 and they could call it seatalk and
charge more, but i'm willing to give them the benefit of the doubt and
think they had a better reason.

There is a better reason in the fact that it is a multiple-access collision
detect protocol which simply means that you can connect more than one device
on a line and they can all talk and listen.

NMEA 2000 is basically a network type of protocol like seatalk, except
it's an open standard that anyone can use. i haven't actually seen the
standard, but it's a protocol and a hardware specification, and i would
assume that it's very similar to rs-232 if not the exact same thing.

NMEA 2000 is far far away from RS-232. Like I said earlier, RS-232 is only
for point-to-point connections while NMEA 2000 (CAN based) is a network for
multiple devices. The standard is open but you have to pay around $10,500
for the documents, test suites and manufacturer/product codes.

Meindert

In article ,
"Meindert Sprang" wrote:

That is obvous...

With all respect Luc, but you're mixing things up very badly in your attempt
to explain things.
I'll comment between the lines:

Meindert, Luc isn't who posted all that confusing info, it was
Purple_Stars, and he really did a hash on most of what he stated,
as you pointed out.

Luc, Peter Bennett in VancoverBC, who posts here alot has a very good
Website, that has a lot of very good information, on specific connection
information, for various pieces of equipment. Might I suggest that
you check that out...

Bruce in alaska
--
add a 2 before @

"Bruce in Alaska" wrote in message
...
In article ,
"Meindert Sprang" wrote:

That is obvous...

With all respect Luc, but you're mixing things up very badly in your
attempt
to explain things.
I'll comment between the lines:

Meindert, Luc isn't who posted all that confusing info, it was
Purple_Stars, and he really did a hash on most of what he stated,
as you pointed out.

Oops... sorry about that!

Meindert

On Thu, 02 Mar 2006 19:57:17 GMT, Bruce in Alaska
wrote:


Luc, Peter Bennett in VancoverBC, who posts here alot has a very good
Website, that has a lot of very good information, on specific connection
information, for various pieces of equipment. Might I suggest that
you check that out...

Bruce in alaska


My site is listed below....

--
Peter Bennett VE7CEI
email: peterbb4 (at) interchange.ubc.ca
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html
Newsgroup new user info: http://vancouver-webpages.com/nnq

thanks for that Bruce, this format is pretty darn good for learning
stuff too.

Meindert,

thanks again for clarifying lots. I'm learning here, and getting a
good laugh at the same time. It sounds like what I want to do is not
only doable, but relatively easy. What is the software side of this?
So far, instruments are communicating, but then when you connect to a
laptop, then what does one need to read this stuff? Chart plotter
style software?

what a great way to learn,

thanks,

Luc