Icom 421 to Garmin 178

matt h · 30 January 2007, 18:18

i know its been done time and time again, well ive done it!!
here goes. step by step to how to link them

The icom 421 comes with 4 leads, the plus and minus are obvious, the other two are phono jack connectors

the RED one goes to the GPS the Black goes to another speaker if you want it,

the red male phono connector/cable (not the one joined to the radio) looks like a single cable, it is not, gently strip it back and you will find a very small red cable in side,
this goes to the thin blue wire on the GPS,feed (Data out in the Gps book)
the stripped back outer wire is the screen wire,
twist it together and tin it with soldering iron, THIS IS THE EARTH, link it to the GPS earth,using solder again,

Press and hold down MENU
go to com 1 on the GPS
and make sure it says NMEA out,

Hopefully that should be working!!

Thats all folks!!

Biggles · 30 January 2007, 18:30

Matt,

I have the same setup. Not wired by me though.
I have been reading up on the things you can do with the 421 and DSC. But the Garmin manual skimps over its DSC capabilities. Do you know if you can Position request with the 421 and have the result automatically shown on the 178 ?

matt h · 30 January 2007, 19:52

i would imagine so as it would sort of defeat the object of having it, but i guess i really not to sure,, um !!

ashbypower · 30 January 2007, 20:17

Biggles, I may be mistaken but I believe the 421 only has NMEA in and not an OUT connection therefore the requested position cannot be sent out.

Regards

Brian

al40 · 30 January 2007, 22:10

Quote:

Originally Posted by ashbypower

Biggles, I may be mistaken but I believe the 421 only has NMEA in and not an OUT connection therefore the requested position cannot be sent out.

Regards

Brian

Agreed - Icom 421 has only got NMEA in. I was interetsed in doing exactly that (displaying DSC messages on the plotter). I can't recall if any of the lower end icom sets had serial in/out (I was originally looking at std horizon with NMEA in/out). In the end, the plotter didn't support the NMEA position out messages from the radio (different format) so I ended up with M421 which is an excellent radio by the way :-)

Jon Brooks · 31 January 2007, 18:08

Biggles et all,

You are correct the M421 has pnly NMEA in and not out.
The M505 has in and out as does the M601/603.

As a point of interest all the Standard Horizon range of fixed radio's in the UK have both NMEA in and out.

Our plotters and indeed Garmin have DSC software built in to allow the showing of position requests and DSC Distress calls.

I am not aware that others allow this as yet.

Best regards

Pete7 · 05 February 2007, 19:02

Quote:

Originally Posted by matt h

looks like a single cable, it is not, gently strip it back and you will find a very small red cable in side

Oh bollicks

oh well another excuse to dismantle the dash. Matt thanks for the tip I was wondering what was wrong,

Pete

Chris · 07 March 2007, 08:26

Quote:

Originally Posted by matt h

twist it together and tin it with soldering iron, THIS IS THE EARTH, link it to the GPS earth,using solder again,
Thats all folks!!

Matt when you say link it to the GPS earth do you mean just run it to you Earth busbar as this is where the black wire from the GPS goes to anyway?

Chris

matt h · 07 March 2007, 08:37

yes thats right, the two must join and then to a secure earth,