Radio intercom

Robin8er · #1 10-05-2017, 09:20 AM

I have a garmin sl40 that has a built in intercom. It seems like nobody uses intercoms that are built into the radio. Is there any reason not to use it? I did a quick search and didnt find anything.

N804RV · #2 10-05-2017, 10:22 AM

It looks to me like it is intended for single comm radio/2 place intercom. If you only intend to have one radio and carry one passenger, then its a great way to go.

But, I think you'll have to jump through a few hoops to integrate a 2nd radio with this setup. Also, is there a way to bring nav audio into this intercom without engineering some sort of home-brew interface?

erich weaver · #3 10-05-2017, 10:33 AM

The general consensus has been that the SL40 intercom sucks. Not the case for the intercom on the newer Garmin GTR200 however, which reportedly works quite well. I refer you to Stein at Stein Air as a higher authority on the matter but think you will hear the same thing from him

erich

noelf · #4 10-05-2017, 11:07 AM

I use a SL 40 as a "portable" radio/ intercom when I am the Ground Controller for our Formation Flight Team.

As a radio, it works great. As an intercom, it also works great. I wired the unit up as a two place radio/ intercom. This allows me to train new guys in our group as I talk to flight lead.

I also have the external "cabin speaker" wired in. This allows me to switch on the speaker so that "other folks...security, LEO's, etc" can listen in if they want.

I do not have any other inputs to the radio / intercom, so no need to switch between different audio sources.

BobTurner · #5 10-05-2017, 11:34 AM

I have an SL-30 - still the best nav-com ever made, IMHO. But the intercom has some issues. Going by memory:
No easy way to input anything other than 2 mikes. Multiplexing in music, for example, will trip the squelch.
IIRC there is only one squelch circuit; one person talks, both mikes go hot. Twice the background noise (not an issue in a quiet airplane, definitely an issue in an RV).
This radio was built when no one had automatic squelch, and the manual squelch adjustment is hidden several layers deep in the menu - an operational challenge if you need to adjust it in flight for some reason.

But within these limitations it does work, and may be a zero extra cost solution for some owners.

Robin8er · #6 10-05-2017, 03:36 PM

Thanks for the info. I'm building an RV 8 and dont have plans for listening to music while flying, so I think I'll just use the radio built in intercom.

snopercod · #7 10-05-2017, 04:23 PM

Quote:

Originally Posted by Robin8er

It seems like nobody uses intercoms that are built into the radio.

I do. My Icom A-210 has an intercom with adjustable settings and it works well.

catmandu · #8 10-05-2017, 04:33 PM

I just upgraded to a GNC-255a and against Stein's advice in a post here from a while back, I ditched the dedicated intercom. Just the two inputs from the headsets with the audio alerts from the GRT into the aux audio on the GNC.

I use the bluetooth function of the headsets for music and telephone. After one adjustment to the intercom settings after the first flight, all squelch and levels have been working fine for some 25 flight hours.

KRviator · #9 10-07-2017, 05:14 PM

I have an Xcom VHF as my single comm radio, and utilise the built-in intercom happily. It even has an external music input available that I use for the Dynon audio, as I have a Bluetooth headset.

Unless the built-in intercom is pretty average, there's no reason not to use it.

DennisRhodes · #10 10-07-2017, 08:26 PM

Quote:

Originally Posted by snopercod

I do. My Icom A-210 has an intercom with adjustable settings and it works well.

if you would sometime please post the setting numbers for that A210 intercom. I also have one but have never found the right settings for mic gain, squelch and etc. I never have been able to use it. Best I remember the mic would stay open all the time due to hi cabin noise level. As result, I added a portable with auto squelch that has worked pretty well.