"Larry W4CSC" wrote in message
...
On Wed, 8 Oct 2003 15:26:45 +0200, "Meindert Sprang"
wrote:


I chose screw terminals. They are rigid and in many cases where people
install equipment, the first thing they'll do is cut off fixed connectors
because the cable has to go through a hole or gland.

I just wish you'd all consider SHIELDING and CONFORMANCE to the NMEA
standard of a BALANCED system....not just you, all of them. It would
sure make listening to HF SSB, NAVTEX, WEFAX and VHF marine bands much
more enjoyable. All this unbalanced, unshielded BS is tearing up the
radios.

Well, first of all, the NMEA standard does not specify to use shielding. It
says in paragraph 3.1 that "interconnection MAY be by means of a
two-conductor, shielded, twisted-pair wire". So, it is not mandatory. And in
my opinion not nesseccary. Think about UTP on 100Mb networks. They can be
quiet with the occasional ferrite ring core at 100Mb. So to be quiet at 4800
bps wouldn't be a problem at all.

Using a balanced system is indeed the best way to go. And with the mandatory
galvanic isolation on the inputs, NMEA-0183 would be a perfect system. If
everybody just made it how it was dictated by the NMEA.....

If you look at our multiplexers, you see there is a GND connection at the
balanced NMEA outputs, to accomodate the connection of the shields, as per
NMEA standard.
And with sufficient internal decoupling and slew rate-control on the
signals, these screw terminals serve their purpose and the whole setup does
not radiate, nor is it susceptible to radiation, all within the FCC/IEC
limits. We tested up to 10V/m.

FCC simply needs to step in and FORCE compliance with all the various
classes of computer interference regulations already on the books. No
type acceptance and conformance to the standard.....no selling it in
the USA.....just like your notebook from Japan.....

I always believed this was already the case. If I ship to the USA, I have to
fill in a form from Fedex, stating that the goods comply with the FCC
regulations. So as far as I know, it already IS illegal to sell goods
without compliance with FCC rules in the USA. It is the same as here in
Europe, where a CE marking is required, indicating that the equipment
complies with the corresponding EC directives, in this case IEC61000-6-1 and
IEC61000-6-3, which is very similar to FCC Title 47 CFR, Part 15 Class B.

The 'funny' thing is, Noland has no FCC compliance..... ;-)

Meindert