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By thegasguy
After a very traumatic and protracted install of a new instrument panel, I have encountered an annoying glitch today.
My new Trig 8.33 TY91 radio works perfectly ( tx and rx) apart from there is no p2 to p1 intercom ( the other way works but is quiet) and no p1 sidetone.
If I pull the p1 small plug out a bit I get the "deadness" disappearing and a little bit of sidetone, but it's not right.
P1 using new Bose ANR and p2 my old faithful DC's.
Oddly, plugging a mate's Zulu ANR into p1 and the Bose into p2 and all is well.
Swapping the DC's and Bose round doesn't work.
I've just read up on setting up squelch and intercom volumes, I'm hoping that fixes it.
Anyone else found this? Silly mis- connection maybe?
We have re- wired just about everything, it's possible.
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By Paul_Sengupta
Is this the recurrence of the old microphone incompatibility thing when fed through a "simple" (connected together) intercom setup?

You might need a separate microphone pre-amp, or a decent intercom, to connect up.
By thegasguy
It shouldn't be the mic problem, the Trig website says that standard aviation headsets will be ok without an intercom.
I have an intercom that I removed, but am really reluctant to re-fit it as there is no room now !
As the plug half-in seems to affect some sort of a change I suspect a faulty socket or wire - it's all been in and out a good few times.
I would love to pop up to the airfield an play with the radio settings but all 3 holiday days up there would make the missus way beyond annoyed!
Another puzzle ( to me) is that there are 4 bands on the plug but only 3 wires in the socket as far as I know.
Fingers crossed I can get it right for the LAA Rally.
By riverrock
4 bands?
Do you have standard Dual GA connectors or one of the other varieties? There should be 2 or three bands / wires in the headphone side of the standard dual GA connectors (ground, right (if stereo), left (also mono) ) plus three bands and 2 or three wires in the microphone side (PTT (optional), mic, ground).
4 bands sounds like you have a different type of connector. When you are pulling it out slightly, a connection will be being made into the ring that you need.
The pins are here: ... ockets.pdf
A TY91 is mono only AFAIK so the stereo ring should either not exist, not be connected or the right and left channels connected to each other. Do you get sound in one ear?

Lightspeed Zulus can be set using dip switches to be mono only (which is the standard I think) so it might be that the Zulus are essentially shorting out the extra ring, getting round the issue. I don't think the Bose A20 are as flexible.

So I'd re-confirm you've got the right headphone socket & it is all wired correctly.
By thegasguy
I've just got out both of my headsets to examine the plugs.
The DC H10.13.4 's have two bands/ connection points on the big plug- main shaft and Chess pawn end pin, and 4 on the small one. I say that there are 4 on the small as I see 3 black insulating rings. First the main body then insulating ring, then a 'waisted in' conductor, then very thin insulator, then plain conducting ring, then insulator (reducing diameter) then pawn shaped end conductor.

The Bose is different, the large plug has an extra insulator in the main conductor to split it in two. ( stereo?)
The small plug is the same, 4 separate sections of metal.

I think it was the small plug giving me trouble, so no surprise that both headsets gave the same fault.

Why Lightspeed Zulu's didn't ( on the ground later) is a curve ball. My mate said they had 4 bands when he checked- to his surprise.

The aircraft has bog standard connectors that worked fine on my old 25khz Icom.

I really want to go to Sywell next week, but won't risk non-radio. Help!
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By Paul_Sengupta
thegasguy wrote:It shouldn't be the mic problem, the Trig website says that standard aviation headsets will be ok without an intercom.

Someone mentioned the Mandy Rice-Davies quote recently...

Anyway, unplug the small plug on the DCs and see what happens. Your passenger will still be able to hear you but you won't be able to hear him/her. See if everything else works when you do that. DC microphones are renowned for pulling down others when you have a "simple" intercom.
By riverrock
thegasguy wrote:The DC H10.13.4 's have two bands/ connection points on the big plug- main shaft and Chess pawn end pin, and 4 on the small one. I say that there are 4 on the small as I see 3 black insulating rings.

Yes - Bose A20 can handle stereo.
There are two types of compatible microphone (small) connector which can go into the same socket.
Even though the military spec 642/5B (bottom) looks to have an extra segment, that whole bit between the two insulation bands is treated as insulation rather than an additional electrical connection, so its only got three connections.

The tip part of the mic lead (push to talk) is generally not connected (was only used for old hand held mics).
By thegasguy
Thanks, that gives me some ideas.
I didn't think to unplug the DC's in flight but p2 could hear me and I couldn't hear him -much as Paul says.
Until I get the menu up on the radio I can't tell if the sidetone and squelch are right down, that might be it - or part of it.
As the two small plug 'bands' are one connection and the tip doesn't do anything, then pulling it back and getting 'something' implies a faulty socket and low volume combined?
Anyway, I can't do any detective work until tomorrow now, so thanks again - fingers crossed.
By thegasguy
Ok- I can put this one to bed.
First, apologies to all helpers- it was the big plug giving me problems not the small one. I can't see them in the air now and they are 'the other way up' on my side.
I first set up the radio volumes etc, but no real improvement.
Then two experienced local pilots helped me to determine that a wire was on the wrong connection. Basically the 'tip' wasn't connecting until I half pulled out the plug, allowing it to touch the erroneously wired ring.
I took off that wire and soldered it onto the tip connector. It worked but crackled- turns out the bit the plug body touches was a poor connection due to a weak spring effect. Some brute force - sorry- careful adjustment, soon sorted that out.
Result, a very clear and impressive radio and intercom-
I can now say that Bose A20 ANR and standard DC's work perfectly together on a Trig TY91 with no need for a seperate intercom.
Thanks to all that helped.
See you at the Rally I hope.
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By Ian Melville
The TY91 has an inbuilt intercom with additional aux input, so unless you want headsets in 4 places or additional aux inputs, there is no need for an external intercom or audio panel.
Though Trig only state the TY91 is comparable with "conventional aircraft headsets", these days most intercoms can cope with different mic requirements.
By thegasguy
The new setup was used 'for real' this weekend and performed perfectly. Only the built in intercom squelch needed adjustment in the air, as the extra noise held it open -leading to white noise all the time.
A bit fiddly as the words are very small on the display, but we managed easily enough and it shouldn't need doing again.
I recommend the Trig Ty91 for use with Bose ANR and DC's based on my experience. I went through Southend CAS to Clacton and back, and everyone heard me, and I heard them as well. Not much else needed really.
By the way, thank you Southend, no fuss; friendly service- as always in my experience and very very kind to my friends in a Luscombe.
By Robin500
Interesting thread, as I've just purchased a TY91 and intend installing it myself! I was/am concerned about the intercom audio quality. Now you've sorted the problem, are you completely satisfied with the intercom audio be crisp and clear?
By thegasguy
I was also concerned about the built in intercom, as I'd only used the usual external one before.
Rest assured, it's really good. Set up the intercom squelch a little higher ( or is that lower ?) than seems necessary on the ground, as the engine noise triggers the mic in flight if you get it wrong. ( exactly as an external intercom would ) Easily sorted out if you practise accessing the settings menus before flying.
The intercom volume is also easily set up and the audio is very clear.
As far as I can tell you don't alter them again after that.
I thnk that the Trig is a cracking bit of kit and easy to fit and use.
Definetly get it from one of the wholesalers that supply a free harness, it's very useful and time saving.
Having the radio gubbins and control head seperate allows it to squeeze into a small panel space as well.
I have no connection with Trig by the way !
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