On Mon, 29 Sep 2003 08:22:42 -0400, "Doug Dotson"
wrote:

Larry,

Are you generally satisfied with the Noland mux? I installed one and
started having problems when the system started to scale up. It doesn't
handle saturation very well. I switched to one od Meindert's Miniplex-USB
units and have been very satisfied.


First, I didn't buy it, the captain did. He had it a while before I
took over the electronics on the boat. I would have found out they
expected you to have the computer running all the time and would have
looked elsewhere. Noland's documentation sucks. I can't find
anywhere it says I have to use the TX output on the computer RS-232C
for raw NMEA output if I don't want to use the computer, but that's
how the thing works. It was made to use with The Cap'n and computer
controlling the network. I have a toggle switch to put the computer
in or out by switching between the TX terminal and the TLK terminals.
That's strike one.....

It's not shielded so it radiates all over the HF bands. Idiots.
You'd think this wasn't going into a BOAT with RADIOS. Idiots.

The TX output can only sink 15ma of current, according to what Roland
told me. Luckily, the load total I have on it is well below that, at
the moment. I'd simply add a switching transistor to boost it but
it's an aggravation and design flaw.

For these reasons, I would have looked elsewhere for a multiplexer. I
doubt I would purchase the one you have because I've borne his nasty
attitude on this newsgroup which would preclude me buying his products
even if they were perfect. Tact is one of a salesman's most important
traits.

Well, I've shielded the Noland in a budbox hooked to the shield system
and will do more of this after the whole system is up and running as
time goes by. Where we'll be operating on HF there's very little
interference, unlike the lower frequencies. Luckily, the Navtex
frequency is in between NMEA harmonics and it works fine. I haven't
monitored 500 Khz in years, but it's also noise free on the Icom.

It's all just too bad they all try to cut each other's throats and
NMEA seems powerless to cause its integration to be consistent with
good engineering practices. The shielded pair balanced line is a fine
idea.....It's just too bad most of them say to hell with it and invent
radiating systems like SeaTalk or Fastnet with unbalanced lines,
unshielded cheap plastic connectors and every place a cable hooks to a
device you're using unshielded screw terminals or cheap plastic
connectors, none of which fit anything else. How stupid they ALL are.



Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?