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Dynon SV-Intercom -2S Opinions ???

Vern

Well Known Member
Is anyone using the Dynon SV-Intercom in lieu of a traditional audio panel?
Your opinion please?

The manual says that if you have two radios you need a microswitch to select the radio that transmits. I suppose one would use the radio volume to select the radio you are listening on.

What say ye?
 
I have the intercom and COMM radio from Dynon. The intercom works fine. You control the volume on it for intercom communications, and the volume knob on the radio for radio communications. I really only adjust the squelch on it between flying and ground operations. It has two audio inputs and both seem to function well for hooking up your iPhone to listen to music or podcasts.

The Dynon COMM has "dual-watch" capability, so I use that whenever I need to be on approach and also try and pick up ATIS. I have the space for the second radio, but haven't put one in yet. Not sure for my use if I would need it or use it for my VFR flying. If I was IFR and/or needing to listen to VOR's, I would get a real audio panel.
 
Is anyone using the Dynon SV-Intercom in lieu of a traditional audio panel?
Your opinion please?

The manual says that if you have two radios you need a microswitch to select the radio that transmits. I suppose one would use the radio volume to select the radio you are listening on.

What say ye?

I have a home-brew intercom which functions similarly. Yes, you use the radio?s volume control(s) to select what you listen to. To ID a VOR, turn up the nav volume (VOR output is wired to an ?always on? input).To swap radios, flip the microswitch, turn up the new volume, turn down the old.
 
Interfacing to GTR 200 and GNC 255

One of the nice features on both these radios is the capability for the audio from the selected frequency to be ported to the left ear and the backup channel ported to the right ear when the monitor function on the radio is selected. The problem is that using the SV-Intecom-2S radio 1 & 2 inputs they take only a mono signal so that the radio feature wouldn?t be available. I wondered if anyone had considered putting a DPDT changeover switch to select between the GTR200 and the GNC255 wiring the intercom radio 1 designated input to the left channel of the selected radio output and the intercom radio 2 input to the right channel of the selected radio input. If this would work it would solve two problems. Having to turn the volume down on the non selected radio and having the capability to monitor the alternate frequency in the other ear. So there would be two switches external to the intercom - one to select the radio being transmitted on - the other to select the radio being listened to. If there were a convenient 3 pole two way switch it could all be achieved with one switch.
May be worth wiring up that configuration and seeing if it works.

KT
 
Turning the volume up and down to switch between coms got a little old, so I just added a "com1/both/com2" switch. It works fine, but had I to do this over again, I'd just bite the bullet and put in a real audio panel. Now I have two switches to flip to go between coms, one for the mike and one for the audio.
 
Update

Since I asked the original question a year ago , I pulled the Dynon unit and put a cover over the hole. I installed a Garmin com panel so my audio would be setup for two com radio use.
 
As I get closer to finishing wiring my panel the issues with using the Dynon intercom for IFR bother me more given the non ideal options for radio switching and control. I haven?t given up yet and switched the intercom out for a more conventional audio control panel but I am close. My original baseline was to not get into designing any electronics (something I did for the first 20 years of my working life). My focus was about staying on track to finish building the airplane and not get sidetracked into electronics design and manufacturing. So its back to the drawing board to figure out a strategy that doesn't require a new panel layout and creates something that will have the features of a conventional audio panel. I may end up with an interim solution. Will post when I have a solution.

KT
 
With the Skyview radio's dual-watch feature, I've pretty well convinced myself that I don't need a second radio, even for IFR. That, in turn, mitigated the same concerns being mentioned here as to the wiring and switchology to allow for two radios.

However, the caveat here is that, well, I'm not instrument-rated yet, so I'm lacking in real-world experience to apply here. Is there a particular IFR situation that would definitively call for two radios instead of just using dual watch? The only thing I can really think of is redundancy in case of a failure. For that, I intend to tote along a handheld, and the plane can either have a switch box to allow tapping into the ship's antenna, or just a remote antenna kit to use inside the plane.

For the type of flying I intend to do (VFR and everyone's favorite "light IFR"), I feel this is a satisfactory setup.
 
In my year-old post above (#3) I mentioned that I have a Dynon-like home built intercom. It takes two actions - a switch, plus ?turn up the volume? - to change transmitters. But, in nearly 9 years of flying this plane, both vfr and ifr, I have transmitted on #2 exactly two times (not counting doing it just to make sure it still works!). Both times were because #1, using a belly-mounted antenna, had trouble on the ground. I feel no need to change audio panels to a more deluxe version. OTOH, I like having two radios. I use #2 radio to listen to ATIS (no switching involved, just turn up the volume). Yes, #1 has a monitor mode, but around here ATC is so busy you have listen on monitor mode about 10 ATIS cycles to get all the numbers. It?s easier to listen on two radios simultaneously.
Same thing for VOR/ILS morse code - just turn up the nav volume so you hear both (although with the SL-30 I actually use a pre-set nav volume and switch it using a button on the SL30 itself).
 
It's a personal decision. I like having two built in coms. Handhelds are lower power and there's the spaghetti of wiring usually involved. Just personal preference plus years of flying certified planes with complete panels.
 
I've been flying the last half dozen years, including IFR, with a single comm radio but with a second "monitor" frequency that will generate audio only when the primary frequency is clear. The monitor frequency works okay and its main use is for getting ATIS in flight. I can also use it on the ground when taxiing for monitoring tower and building situational awareness so that I have a clue as to what traffic is in the area before I call in the first time.

I (long, irrelevant story) came across a Comm 2 that will fit in the panel without cutting metal, and I'm going to install it and wire it in to the existing audio panel some time. The main advantage is that when I receive a departure frequency from clearance delivery, I can put that into a radio right away, even though it won't be the next frequency used (clearance, ground, tower, departure). I'll also be able to monitor 121.5 all the time, and I think we're all still supposed to do that if we can.

As for having a switch for transmitter select and turning volumes up and down -- don't. If you regularly switch radios, that will be a big pain.

BTW, in the bad old days before flip/flop radios, the deluxe setup was two radios (!). To switch from one to the other, you used the audio panel to swap transmitters with a toggle switch or knob, then turn off one comm with one toggle switch and turn on the other comm with another toggle switch. It was really cool when audio panels came with an AUTO function that would swap receiver and transmitter together. I think the custom of audio panel atop the stack came from those days, when the audio panel was used so frequently. These days, I think the autopilot controller deserves top billing.
 
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Ed, please report back in a year. I?ll bet that you find that you do not regularly switch between transmitters.
Yes, I recall the bad old days. A common error was for students (primary or instrument) to forget which of the two radios they were actually using, and then change the ?active? one instead of the ?standby? one. Modern flip-flops are a great idea!
 
Ed, please report back in a year. I’ll bet that you find that you do not regularly switch between transmitters.
Yes, I recall the bad old days. A common error was for students (primary or instrument) to forget which of the two radios they were actually using, and then change the ‘active’ one instead of the ‘standby’ one. Modern flip-flops are a great idea!

I've been flying behind the Dynon SV-Intercom and Dynon Radio for around 3 years and 250 hours. I make use of the radio monitor function to listen to a second frequency fairly often. It's very useful, and short of having two radios, it's a nice feature. I'm now making some panel changes and adding an IFD-440, so will have two radios and have been thinking about alternate ways to handle this. My current bias is to add a second switch on the grip to toggle between transmit radio 1/2. I was planning on just turning the volume up/down/off for listening, but since I'm cutting a panel, am now thinking of putting a radio 1/both/2 switch on the panel for receive.

This discussion has been helpful. I suspect I won't often switch to radio 2 unless having tx/rx difficulties. My antenna is on the belly, and my home class D airport is one that I can't talk to all that well on the ground, so it might be better from the new IFD with its antenna in the wingtip. I'll also try to report back on this thread in a year after flying behind the new set up.
 
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Ed, please report back in a year. I?ll bet that you find that you do not regularly switch between transmitters.

You'd lose that bet. The plan is that #2 will have stored frequencies for 121.5, ATIS, clearance and ground at home base. Once I go to tower, I'll use only comm 1 for the rest of the flight with #2 monitoring 121.5.

If I'm away from home base, I'll use #2 the same way at class D/C airports, but won't preset the frequencies.

But we'll see in a year...
 
Stereo radios with the SV-Intercom

I sent a question off to Dynon support and got a call back about interfacing the Garmin radios to the SV-intercom with the intent of preserving the stereo capability of listening to the primary radio channel through the left earphone and the standby channel through the right earphone. I floated the idea of using the HDX non-muted input pins switched between radios as the radio input and wire the HDX input to one of the radio inputs through an externally mounted summing amp since I don?t need Dynon?s Flossy speaking to me in Stereo. (I know - I said I wasn't going to get back into any electronics design work). Dynon tech support thought that was an interesting idea but didn?t offer any confirmation it would work or compatibility with signal levels, impedance etc. Tech support did offer to pass my suggestion along to their engineering dept. if I wrote it up in an email, which I will do. While I was considering how to switch the TX and RX signals I did a quick search on the web for illuminated audio panel like switches that would work for the human interface of making this look and work like a standard audio panel. I found some nice LED illuminated latching push button switches and ordered some samples of different colors. I have room alongside the intercom to mount four of the selected switches for control of the two radio audio and transmit functions so will finish filling in the details when I have more information from Dynon engineering or have built and tested a prototype whichever comes first.
KT
 
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