Radios ... what to get?

Have you ever heard a super clear, crisp transmission from an aircraft? Not often, but every once in a while I hear someone call in, and the audio quality is excellent. I always want to run down that pilot/aircraft and see what is in his stack.

I'd love to sound that good. I am in the planning stages for my panel, and I've decided on Dynon for the EFIS part, but there are various compatible, non-Dynon radios, as well as Dynon's offerings to choose from.

Any advice on radio/intercom/headset combos to achieve audio nirvana?

Easy..

Either a Garmin SL-30 or -40 are both crisp and clear.

Best,

Others have reported that we have a very clear audio, thats the configuration:

Headset: Bose Aviation X
Audio Panel / Intercom: Garmin GMA340
Radio: Garmin SL30

We have also a GTN installed but the audio quality of the SL30 is better (the gtn is still an excellent unit).

Not only the components are necessary for good audio, also the wiring where noise could be induced is important, as well as a good antenna system.

Read also Bub Nuckolls Aero Electric book, specially the Grounding and Noise chapters.

I have had good luck with the iCom 200 and 210. In checking their website, I noticed they now have a 220 but I'm not sure what the difference between the 210 and 220 are.

I've heard nothing but glowing reports on the Garmin GTR200 which includes an excellent built in intercom.

Dynon EFIS / Radio

I have a Skyview Touch 10" with the Dynon Comm and Intercom. If you go with Dynon, you'll appreciate the tight integration between the EFIS and the radio / intercom. Being able to pass off all the frequencies from your EFIS selected airport, with one button, is really nice. You also control many of the radio and intercom setup functions directly from the EFIS. I've never operated another radio with the Dynon so I'm not saying they won't work equally well. I'm just suggesting you research the level of integration you may give up (or gain?) if you choose a non Dynon radio. My all-Dynon setup with either my Bose X or LightSpeed Zulu get's great reports and has excellent reception.

wjb said:

Have you ever heard a super clear, crisp transmission from an aircraft? Not often, but every once in a while I hear someone call in, and the audio quality is excellent. I always want to run down that pilot/aircraft and see what is in his stack.

I'd love to sound that good. I am in the planning stages for my panel, and I've decided on Dynon for the EFIS part, but there are various compatible, non-Dynon radios, as well as Dynon's offerings to choose from.

Any advice on radio/intercom/headset combos to achieve audio nirvana?

Click to expand...

I thought the same thing and went old school for comm #1- a KX-155 - when I made the decision. No regrets.

I'd add also that the antenna and proper cabling plays a part here as well - maybe as much or moreso than the radio. Ensuring a proper ground plane, high quality antenna, and good connections are all examples of factors that come into play here.

Microphones

As a manufacturer of microphones (not for aviation) I am often surprised at how little attention people pay to that part of the system. Grounding, antenna mounting and location, solid power wiring are all very important. The antenna mounting and ground plane issues are equally about keeping the RF fields out of the audio wiring as they are for radio coverage. Most of the recent (last 20 years) radios from the bigger companies have very good audio quality for transmit and receive. The big jump was with the later King Silver Crown and Collins Microline models. The microphones however are all over the map, and people don't take the time to adjust the microphone gain in the radio and/or the microphone output level for consistent modulation.

If you're looking for crisp military-style transmit audio, use the microphones they do, preferably the noise cancelling dynamic types like the M87/AIC (from any of the mil vendors.) You will need a preamp/impedance converter for use with civilian radios, but they are readily available and some mics have them built-in. The more modern electret noise cancelling mics like the Gentex 5060-4 are also good. Some radios (the Garmins for instance) have fairly good automatic gain control, but for others you really need to check your mic with your radio and a modulation meter or scope and adjust the radio's mic gain. It's not hard to do, but confirm that the levels are set correctly, and keep the microphone at the same distance from your mouth when you're using it.

dljosephson said:

but for others you really need to check your mic with your radio and a modulation meter or scope and adjust the radio's mic gain. It's not hard to do, but confirm that the levels are set correctly,

Click to expand...

That is if you happen to have a modulation meter or scope handy------and know how to use it, and what to look for, and how to correct the issue if you find one.

Not trying to be a smartass here, but you are a professional in the business------most of us are just homebuilders.

Never heard myself but I love my SL40. It is all I have, which was an eye opener for me too. I had never flown with one radio before I bought this plane and now I have absolutley no desire to have a second. I am VFR only though. Works for me.

Be careful what you wish for

This is complicated. If the guy transmitting is sitting on the ramp a mile away, engine off, then the best sound quality will be when everything in the system - mike, audio amp, transmitter, receiver, audio, headphones - has a wide frequency passband, 20 to 20,000 Hz. But add a noisy cockpit, move him 40 miles away (weaker signal), and he won't sound as good - too much background noise. In that case a system with a more restricted passband will sound better, as it removes more noise than important signal. Getting that compromise optimized is the tough trick. A good mic is a good start. Some audio panels will attempt to recognize repetitive noise like engine and prop and selectively remove those signals. This takes a lot of digital sophistication.

GTR 200 is the way to go

The Garmin GTR 200 radio is awesome. Been flying with it for over a year. Crystal clear reception and transmission. The built-in 2 place intercom is great.

Upgrade my panel and replaced the SL40 with the GTR200. No regrets.

M87

As a another microphone engineer, just curious what characteristic about the M87 dynamic NC mic lends itself to better performance in this application compared to an electret condenser NC microphone?

GTR200

I have also used the Garmin GTR200 for almost two year with excellent transmit and receive clarity. The stereo intercom is also a nice feature that works very well.

Chad