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Gert Been
 
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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

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


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Wout B
 
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"Gert Been" 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

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


Our new multiplexers have opto-isolated inputs and are compliant with CE
emission requirements. Strange that I first hear from you via this
newsgroup. Would you not have contacted us with your complaint if you had
not come across this newsgroup thread? You say you have just installed one
of our multiplexers. I have checked our records, but we don't have you
listed as a recent direct customer.
If you have any kind of problem with a multiplexer, we'll be happy to assist
if you contact us via the normal channel. Your problem can be easily
resolved. All you need to do is send us an email and let us know where and
when you bought your multiplexer.
Wout




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Larry W4CSC
 
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"Wout B" wrote in
:

Our new multiplexers have opto-isolated inputs and are compliant with
CE emission requirements. Strange that I first hear from you via this
newsgroup. Would you not have contacted us with your complaint if you
had not come across this newsgroup thread? You say you have just
installed one of our multiplexers. I have checked our records, but we
don't have you listed as a recent direct customer.
If you have any kind of problem with a multiplexer, we'll be happy to
assist if you contact us via the normal channel. Your problem can be
easily resolved. All you need to do is send us an email and let us
know where and when you bought your multiplexer.
Wout



Translation - "Shhhh.....don't say bad things about boat products in public
forums like newsgroups".......

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Larry W4CSC
 
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"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^

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Meindert Sprang
 
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"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




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Larry W4CSC
 
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"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;

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Meindert Sprang
 
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"Larry W4CSC" wrote in message
...
"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;


Yeah Yeah.....

When you are installing this stuff for living, you very soon learn to
appreciate the absence of fixed connectors on cables..... or do you want to
make all holes in bulkeads bug enough for all connectors to push
through..... just once.....

Meindert


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engsol
 
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On Mon, 14 Mar 2005 07:02:18 +0100, "Meindert Sprang" wrote:

"Larry W4CSC" wrote in message
...
"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;


Yeah Yeah.....

When you are installing this stuff for living, you very soon learn to
appreciate the absence of fixed connectors on cables..... or do you want to
make all holes in bulkeads bug enough for all connectors to push
through..... just once.....

Meindert


Am I over looking something? Can't the cable be routed,
then the connectors installed? Might make a neater
installation, avoiding coils of excess cable....or cables
which might be too short.
Norm B
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Meindert Sprang
 
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"engsol" wrote in message
...
On Mon, 14 Mar 2005 07:02:18 +0100, "Meindert Sprang"

wrote:

When you are installing this stuff for living, you very soon learn to
appreciate the absence of fixed connectors on cables..... or do you want

to
make all holes in bulkeads bug enough for all connectors to push
through..... just once.....

Meindert


Am I over looking something? Can't the cable be routed,
then the connectors installed? Might make a neater
installation, avoiding coils of excess cable....or cables
which might be too short.


No, you're not overlooking. But it just feels plain stupid to first cut the
plugs, route the cables and then reassemble them. What would you like to do
most: solder a plug with tiny contacts or just strip the wire, crimp on a
pin and screw them into a screw terminal?

And believe me, it's not just theory but this is backed up with
measurements: a 4800 baud signal is just not going to produce interference
because the last inch is not screened and connected to screw terminals. They
are physically too small to be able to radiate enough energy to interfere
with an SSB.

Meindert


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Doug Dotson
 
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Have you priced a crimping machine that is capable of dealing with most
reasonable moisture proof connectors?

Doug

"engsol" wrote in message
...
On Mon, 14 Mar 2005 07:02:18 +0100, "Meindert Sprang"
wrote:

"Larry W4CSC" wrote in message
...
"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;


Yeah Yeah.....

When you are installing this stuff for living, you very soon learn to
appreciate the absence of fixed connectors on cables..... or do you want
to
make all holes in bulkeads bug enough for all connectors to push
through..... just once.....

Meindert


Am I over looking something? Can't the cable be routed,
then the connectors installed? Might make a neater
installation, avoiding coils of excess cable....or cables
which might be too short.
Norm B





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