Mike Reinath wrote:

"I amthinking of using a Mini Circuits ZFSC-2-1 splitter (5-500 MHz), available
on eBay, to split the signal. One output would go to the SL-30. The other
would go to a diplexer and into the VOR and GS inputs of the 430."

I have hooked up SL30/430 installations using the combination you've described and it works fine.  I once tried a Comant CI-505 which connects to a single nav antennaa and provides 2 VOR outputs and a glideslope output. While this works fine for the 430 the SL30 receives VOR only, no glideslope. (If I'd thought about it a little harder I would have realized this was the case before I tried the CI-505.  Gotta remember to think before I buy.)

Another combination that will work is a Comant CI-502 followed by a Comant CI-507.  The CI-502 splits the signal, same as the Mini-Circuits part, but probably costs more.

Tom Gourley