Adding an SL-30

I plan to add a Garmin SL-30 to my Garmin stack (GNS430, GTX430 transponder, GMA 340 Audio Panel, CDI) I have a Comant comm antenna, Archer VOR/GS antenna with a Comant splitter for the 430.

So, what do I need to do?

Do I need a 2ND comm antenna?

Do I need a triplexer/ 2nd splitter to split off signal to the SL-30?

Is there an easy way to toggle between the 430 and SL-30 signal to the CDI?

What is the nature of the wire harness sold with the SL-30 by Van's and Stark?

Lots of questions, many thanks for help.

Roy Samuelson
RV7A (Flying whenever it stops raining)

Lots of wiring!

Hi Roy,
I have a Garmin 300XL Com/GPS with a Narco MK-12D Nav/Com. In order to switch the CDI (HSI in my case) I had to add a MSI Avionics INSSDU III relay box and annunciator panel. You may not need that much for your setup but it does require relays that allow you to switch the CDI between the two sources (radios). I also put a second com antenna on so I didn't have to deal with any kind of isolating tap. As for the Nav function, I originally had a diplexer when I had two Nav units. Don't cascade (put two in series i.e. output of one into input of second), diplexers or you can loose a lot of signal strength for the downstream nav unit.
Hope this makes sense. As always, your milage may vary!

Paul

pczar3
RV-6A
N694BP reserved.

If you desire to run the same CDI, then indeed you'll need some sort of multiple pole relay to switch the feed to the CDI. I'd recommend a 2nd Comm antenna for the SL-30, either a bent whip or straight whip (top or bottom)... The SL-30 has a built in Diplexer for GS, but you'll still need to feed it a NAV lead, either from an existing one, or a new one so a larger splitter may be in order if you want to feed it from the existing archer.

Regarding the harnesses from Stark & Van's, they are like all of us Garmin Dealers - built to your spec's. FYI...Van's doesn't actually do their own harnesses, they come from another shop.

There really can't be a good "canned" or one size fits all harness, because the leads differ depending on what you're hooking the SL-30 to. With an EFIS there are a lot less wires than an analog CDI, so of course that changes the harness requirements. If you want a lead for hook into a 396/496 it's a simple serial wire. Powers/Grounds are pretty straight forward, as are the audio lines. You just need to spec the lengths you want along with what you're hooking the radio up to.

Just my 2 cents as usual...

Cheers,
Stein