Wayne,

You may want to consider using a Mini-Circuits ZFSC-2-1B splitter. I bought
one on eBay for around $12 plus shipping last year. I used it to connect my
SL-30 and Garmin 430 to a single Bob Archer antenna. First I split the
antenna output with the Mini-Circuits splitter. One line goes to the SL-30.
The other goes to a diplexer with VOR and GS outputs. These go to the 430.
Works okay, but it does reduce the range a little.

Mike Reinath
LNC2 N3602M
San Jose, CA