"Gert Been" wrote in
:

Ehh, talking about "Decent" multiplexers: decent multiplexers have
isolated inputs, yours don't.

I just connected one of yours to a differential NMEA talker output. I
can
now hear all NMEA data on my SSB!!

While trying to find out what's wrong, I found that all inputs on your
multiplexer have the B terminals connected to ground!!! NMEA inputs
are supposed to be isolated. Your grounded B terminals on the inputs
effectively short-circuit any properly designed talker. Was it that
hard to add 50 cents worth of optocouplers?

Gert



This is one of my pet peeves with most manufacturers. STupid Icom's really
expensive M-802 uses a BNC RF connector that only has ONE WIRE and ground
to hook the NMEA data to the transceiver for DSC/GMDSS GPS input. They
should all be HUNG! If everything had a balanced line like NMEA was
designed for, I could probably transmit on HF without tearing up the whole
boat's NMEA network....(d^

"Larry W4CSC" wrote in message
...

This is one of my pet peeves with most manufacturers. STupid Icom's
really
expensive M-802 uses a BNC RF connector that only has ONE WIRE and ground
to hook the NMEA data to the transceiver for DSC/GMDSS GPS input. They
should all be HUNG! If everything had a balanced line like NMEA was
designed for, I could probably transmit on HF without tearing up the whole
boat's NMEA network....(d^

I agree completely. NMEA should have simply revoked membership of anyone not
adhering to the standard. The NMEA-0183 spec is very clear on the naming of
the terminals, what signals they should carry and the required isolation on
every input. So if everyone adhered to the standard, connecting NMEA would
have been as easy as connecting a ligthbulb.....

Meindert

"Meindert Sprang" wrote in
:

So if everyone adhered to the standard, connecting NMEA would
have been as easy as connecting a ligthbulb.....

Meindert


An all multiplexers should use STANDARDIZED SHIELDED CONNECTORS, not some
open screw terminals just waiting for something to touch
them.......grrrr.....(c;

"Gert Been" wrote in message
...

Ehh, talking about "Decent" multiplexers: decent multiplexers have
isolated
inputs, yours don't.

I just connected one of yours to a differential NMEA talker output. I can
now hear all NMEA data on my SSB!!

While trying to find out what's wrong, I found that all inputs on your
multiplexer have the B terminals connected to ground!!! NMEA inputs are
supposed to be isolated. Your grounded B terminals on the inputs
effectively
short-circuit any properly designed talker. Was it that hard to add 50
cents
worth of optocouplers?

Ouch!!!

Meindert

"Glenn Ashmore" wrote in message
news:zJ6Xd.54333$SF.21876@lakeread08...
Almost all GPSs have anchor watch alarms and radars have range alarms but
they all put out a whimpy little beep. Is there a device that monitors
the
NMEA data streams (from say a multiplexer) and make a noise that will get
your attention when it sees an alarm or MOB statement??

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


Hi,
Talking about "decent" multiplexers, all our NMEA multiplexers have
"automatic GPS back-up switching" (plus many other NMEA sentence management
features). Read about it he
http://brookhouseonline.com/gps_backup_switching.htm . I have been
playing with the idea to add a buzzer to warn the user when it switches to
the backup GPS. As the "no GPS data" detection is already present, this is
very simple to do. If there is sufficient interest, we'll include it as a
standard feature. If you want it NOW, we'll add a buzzer to the present
model for a small charge if you decide to buy one.
Wout
Brookhouse

"Wout B" wrote in message
...

Hi,
Talking about "decent" multiplexers, all our NMEA multiplexers have
"automatic GPS back-up switching" (plus many other NMEA sentence
management
features). Read about it he
http://brookhouseonline.com/gps_backup_switching.htm . I have been
playing with the idea to add a buzzer to warn the user when it switches to
the backup GPS. As the "no GPS data" detection is already present, this
is
very simple to do. If there is sufficient interest, we'll include it as a
standard feature. If you want it NOW, we'll add a buzzer to the present
model for a small charge if you decide to buy one.
Wout
Brookhouse

"Now" is a relative term. I have been working on this boat for 6 years and
am now in the "deep pockets" major boat bucks phase. It will be a year
before I could afford to buy one if you made it. :-).

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

On Tue, 8 Mar 2005 21:24:05 -0500, "Glenn Ashmore"
wrote:

I have been working on this boat for 6 years and
am now in the "deep pockets" major boat bucks phase. It will be a year
before I could afford to buy one if you made it. :-).

==========================

Sheesh, even with all of those anchors I've bought?

:-)

"Wout B" wrote in
:

Hi,
Talking about "decent" multiplexers, all our NMEA multiplexers have
"automatic GPS back-up switching" (plus many other NMEA sentence
management features). Read about it he
http://brookhouseonline.com/gps_backup_switching.htm . I have
been playing with the idea to add a buzzer to warn the user when it
switches to the backup GPS. As the "no GPS data" detection is already
present, this is very simple to do. If there is sufficient interest,
we'll include it as a standard feature. If you want it NOW, we'll add
a buzzer to the present model for a small charge if you decide to buy
one. Wout
Brookhouse

I'd rather see shielded connectors so I can run shielded pair cables and RF
bypassing of all inputs to keep the HF SSB from screwing all the NMEA crap
attached to it. Shielding everything would also make it so we could HEAR
the HF receiver and get our WEFAXes without the constant drone of NMEA
radiated interference from all the unshielded, unbalanced connections with
just open wires sticking out of things. NMEA needs to get its act together
and enforce some standards on its members....

Of course, we could dump all this proprietary crap and just wire the boat
for Ethernet, negating the need for multiplexers in 1970 serial
connections. Ahhhh....addressable Ethernet instruments all speaking the
SAME language through a good $49 wireless Netgear router to the wireless
laptop in my berth....(c;

Larry,
Do you have ferite beads at both ends of all your NMEA cables? If so, do
they help?
krj

Larry W4CSC wrote:
"Wout B" wrote in
:


Hi,
Talking about "decent" multiplexers, all our NMEA multiplexers have
"automatic GPS back-up switching" (plus many other NMEA sentence
management features). Read about it he
http://brookhouseonline.com/gps_backup_switching.htm . I have
been playing with the idea to add a buzzer to warn the user when it
switches to the backup GPS. As the "no GPS data" detection is already
present, this is very simple to do. If there is sufficient interest,
we'll include it as a standard feature. If you want it NOW, we'll add
a buzzer to the present model for a small charge if you decide to buy
one. Wout
Brookhouse


I'd rather see shielded connectors so I can run shielded pair cables and RF
bypassing of all inputs to keep the HF SSB from screwing all the NMEA crap
attached to it. Shielding everything would also make it so we could HEAR
the HF receiver and get our WEFAXes without the constant drone of NMEA
radiated interference from all the unshielded, unbalanced connections with
just open wires sticking out of things. NMEA needs to get its act together
and enforce some standards on its members....

Of course, we could dump all this proprietary crap and just wire the boat
for Ethernet, negating the need for multiplexers in 1970 serial
connections. Ahhhh....addressable Ethernet instruments all speaking the
SAME language through a good $49 wireless Netgear router to the wireless
laptop in my berth....(c;

"krj" wrote in message
. ..
Larry,
Do you have ferite beads at both ends of all your NMEA cables? If so, do
they help?

Ferrite beads don't do much on HF, but all the more on VHF. But like I said
in me other replay, it's more important to terminate the wire correctly. If
you have a shield, do not use it as a signal return as with coaxial cable.
Only connect it on one side so no current can flow through the shield,
otherwise it will radiate being a perfect antenna.

Meindert