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MGL V6 teething problems

G

gerrychuck

Well Known Member
My local avionics guy installed a new MGL V6 for me last week, and my first opportunity to use it was today. Unfortunately, all did not go well. I use an ANR retrofitted (Headsets Inc kit) HGU 55 helmet, and although I was able to transmit and receive through it, I couldn't get enough volume to be able to understand transmissions or hear sidetone well enough to try flying with it, although I could hear well enough (barely) on the ground with the engine off. Tried one of my Lightspeed ANR headsets, and it was marginally better, so I tried flying with it, but volume was nowhere near enough to be able to understand what was being said to me. Later, in the hangar, I tried a DC H.10.30 set, which was no better. With all headsets/helmet, transmissions to the unicom base 500 yards away were received 5x5, but my hangar renter reported hearing me call when backtracking on the runway (he was inbound) and said that transmit quality was poor. Talked to my avionics guy, and he suspects the d-sub connector behind the radio is not mating properly, which he was concerned prior to this and was planning on replacing before I fly to OSH this weekend.

So...while my tech is troubleshooting, is there anything in the setup menus that I am missing here? There are mic level adjustments, but I don't see anything with regard to volume, aside from the obvious - the volume knob on the unit.

Gotta get this fixed this week, or my first trip to OSH is off:( Any ideas or insights appreciated.

On a related note, I was trying out my Vertex handheld tonight, with the headset adapter I bought for it. Very low volume on receive and no response to transmitted radio checks using either the helmet or the Lightspeed headset, with excellent volume and no problem with transmit using the radio in its
"bare" mode without the headsets. Tried my trusty David Clarks, and they worked perfectly through the handheld. Tried changing to new batteries for the helmet and Lightspeed with no change in performance. Then I tried my OTHER, identical Lightspeed set, which worked as well as the David Clarks! Tried going back and forth a few times, with the same results; one Lightspeed set works perfectly, as well as the David Clark passive set, and the other Lightspeed set works very poorly, as does the helmet. I really don't get this...
 
For receive, try just pushing the big Jack in to the first click. You may have stereo wiring glitch. For transmit, review the manual section on setting mic levels. Sounds like your headset/helmet mics may be all over the place. Start with your passive Clark's and VOGAD setting on medium.
 
aerhed said:
For receive, try just pushing the big Jack in to the first click. You may have stereo wiring glitch. For transmit, review the manual section on setting mic levels. Sounds like your headset/helmet mics may be all over the place. Start with your passive Clark's and VOGAD setting on medium.
Click to expand...


VOGAD....ah yes. I forgot to mention that my standalone PS Engneering intercom is still installed and working. The original plan was to do the full install of my GRT HX system, plus the V6, with everything properly coordinated, but my avionics guy informed me a few weeks ago that he would not be able to get the whole project done before Oshkosh, so I asked if he could get the V6 in by itself, as I really wanted the dual scan capability flying down in loose form with a friend. Kind of wished I'd stayed with my well-sorted and trusty Becker right about now. I will try the trick with the phone jack; thanks.

As for the mics, both the David Clark passive headset and the helmet are using David Clark electrets.
 
Judging by your description you have some serious wiring or setup issues.

You mention that you have an external intercom system.
If that is the case the manual tells you to switch the internal intercom system off. Having both on can lead to some interesting results - they are rarely what you expect.
Switch the IC sidetone completely off - that task is now left with the external intercom system. Leave only the TX sidetone.
Make sure your wiring guy has actually used the correct audio outputs. There are a bunch of them and they are stereo plus there is one mono which is often mistaken for what it is - it's intended to feed a black box voice recorder.
Make sure your wiring guy has not simply connected the two stereo outputs together. That is a no-no. In your case you can just use one of the outputs (the pilot one, you can likely ignore the pax output since your external intercom does that).

You now have a more complex system with various level controls for both mic level (on the radio and likely another one for the intercom - the signal it sends to the radio). You need to balance this so things will work.
You have the same situation the other way around - a level on the radio (volume) and likely two levels on the external intercom system (input level and volume). You need to set that up.
Set your mic levels at the radio to 0db (that's kind of mid range). Now at least you have a reference and then adjust the external intercom so it sends a decent audio level to the radio for TX. The transmitter in the V6 has an automatic gain control so it will compensate over a fairly wide range.

On the receive side - make sure your volume on the radio is about mid-way and then use all other adjustments on the external intercom. If you can't get enough volume out of it - you definitely have a wiring issue - the V6 can drive a speaker directly and has plenty of audio output power.

Now to your TX. Good TX at short range but not if there is a few hundred yards of space in-between sounds like trouble. Have you connected an SWR/Power meter between your radio and the antenna ? Does the radio produce its advertised power (should be around 6-7W) and do you get a good (that means low) SWR which would indicate that the antenna is matched and is likely working ?

Be aware that a bad match under some circumstances (where frequency and cable length conspire against you) can blow the transmitter if you try hard enough.
A radio with a blown transmitter does indeed still work most of the time but only has very short range as the power available to the antenna is very low and comes mostly from a pre-driver.

Make sure your installer knows what he is doing. You get some excellent guys in our experience but unfortunately not all of them are. The comment that the issue is likely due to a connector mating problem is somewhat worrisome.

Rainier

CEO MGL Avionics
 
Great Product Support

Yep, that's definitely the kind of support that makes or breaks a small company. Nice job MGL!
 
Thanks Rainier! I very much agree with the two posters above; your response is very much appreciated and does represent an impressive level of customer service.

I think TX is pretty strong; I did have one report of weak transmit, but every radio check I did was read back as 5 x 5, and the last couple I did I was broadcasting from inside my metal hangar, with the door closed, and was still read clearly a few hundred meters away. I'm pretty confident that generating adequate volume receiving transmissions is my main issue. Clarity is fine as well; I just don't have enough volume.

I will go through the menus to make sure settings are as you suggest. I'll have to figure out how to set input level on the intercom. Changing the volume level on the intercom doesn't seem to affect the volume from the radio, and didn't with the previous installation either.

I will run your comments by my avionics tech. He is very experienced. I think the comment from him regarding the connector was a bit of a quick reaction based on the fact that he was already concerned with the engagement of the positronic anti-vibration locks he re-used from the Becker installation, and that his initial radio checks when he did the install seemed to work well.

Thanks again for the quick and helpful response.
 
And the winner is....wired to wrong audio output. My guy compared his wiring drawing to Rainier's information,came over and changed to the "pilot left" pin from "audio out", and I have all the volume I can handle and then some.

The upside to all this is that I ended up spending a lot of time working through the radio's menus and ended up learning a lot about how it works in a very short period of time.

Thanks to everyone who provided suggestions, and particularly to Rainier for taking the time to respond in detail, which saved a huge amount of troubleshooting time and led us directly to the problem and the fix. This is my first contact with MGL, and I am very favourably impressed! Thanks again:)
 
Very glad to be of help - that's what I'm here for.

Even more glad that it was something small (it usually is) and that you have a capable tech to sort you out (A good technician is worth his/her weight in gold).

Sometimes we get people installing these things that, well, should not be doing this and it can become really difficult and frustrating to sort out the mess. I am happy this is not the case this time.

Rainier

CEO MGL Avionics

(I'm just signing with this as I got blasted many years ago on this forum for not posting under my credentials - that was an innocent mistake I'm not about to repeat - thanks for understanding)
 
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