Auto Mute with Sigtronics Sport 200 and Yaesu FTA550

The place to raise issues, ask questions, swap ideas and discuss anything related to aircraft engineering, maintenance and building.
NB Any opinions expressed in this forum are not necessarily those of LAA Engineering

Moderators: John Dean, Moderator

Post Reply
garich
Posts: 8
Joined: Mon Jul 07, 2014 1:01 pm

Auto Mute with Sigtronics Sport 200 and Yaesu FTA550

Post by garich » Sun Sep 06, 2020 1:05 pm

Dear Forum,

We have recently installed a Sigtronics SP200 intercom and a Yaesu FTA 550 handheld 8.33KhZ compliant radio in our Jodel D1112.

All functions are found to be working satisfactorily but, annoyingly, all inbound transmissions mute whatever is being said on the intercom.

Not a problem if flying solo but with pax onboard the constant interruption when in the circuit or enroute and monitoring LARS frequencies is proving tedious.

There does not appear to be a selectable "auto mute" option on either the intercom or the radio.

Has anyone else found this a problem and more importantly, found a solution?

Yours in head-scratching puzzlement,

Garic
Garic Howles
040925

Ian Melville
Posts: 914
Joined: Mon Feb 11, 2008 8:21 pm

Re: Auto Mute with Sigtronics Sport 200 and Yaesu FTA550

Post by Ian Melville » Sun Sep 06, 2020 4:55 pm

Can you clarify which model you have?
SP200 or SP200S?
Ian Melville
032644

garich
Posts: 8
Joined: Mon Jul 07, 2014 1:01 pm

Re: Auto Mute with Sigtronics Sport 200 and Yaesu FTA550

Post by garich » Mon Sep 07, 2020 7:33 am

Hi Ian,

We have the SP200.

Cheers,

G
Garic Howles
040925

Ian Melville
Posts: 914
Joined: Mon Feb 11, 2008 8:21 pm

Re: Auto Mute with Sigtronics Sport 200 and Yaesu FTA550

Post by Ian Melville » Mon Sep 07, 2020 2:02 pm

The reason I ment ask, is because the SP200S has...
If you like to listen to music when you fly, then the Sport 200 S Stereo is for you. Use Satellite Radio, MP3 or CD players as your audio source with stereo headsets for true stereo sound. With full or partial music muting for intercom and full mute for radio reception and transmission, you will be able to enjoy your music and never miss a radio call. When radio / intercom use is ended the music will gradually return to its previous volume.
Which if wired incorrectly could cause the symptons you are getting.
I cannot see any mention of a Mute function on the SP200 (as you found out). However it may be considered the normal? It may be that Sigtronics have decided that incomming Radio takes priority over Intercom, but I would have expected to have had a say in that decision and have something like the jumpers mentioned for the SP200S, and it to be documented.

I have a FTA550 and headset adaptor, all I have to do is find the SP200 I am sure is kicking around somewhere! and I can try it on the bench. I am assuming yours is installed as per the FTA750 instructions?
Ian Melville
032644

garich
Posts: 8
Joined: Mon Jul 07, 2014 1:01 pm

Re: Auto Mute with Sigtronics Sport 200 and Yaesu FTA550

Post by garich » Tue Sep 08, 2020 8:10 am

Hi Ian,

"yes", we installed the SP200 following the diagram for the Yaesu 750, as found on the Sigtronics website.

The one bit we haven't implemented is the "optional" 1/2 or 1/4 watt resistor in the blue circuit for the aircraft headphone jack.

The brown and white wires connect directly to the jack for the Yaesu headset adapter as we do not have an aircraft hand mic socket.

Thanks for taking the trouble to look into this.

Cheers,

Garic
Garic Howles
040925

garich
Posts: 8
Joined: Mon Jul 07, 2014 1:01 pm

Re: Auto Mute with Sigtronics Sport 200 and Yaesu FTA550

Post by garich » Thu Sep 10, 2020 4:50 pm

Dear All,

Have just been talking to "Dino" over at Sigtronics in California and he has confirmed that the SP 200 should not be muting the intercom when receiving inbound transmissions.

He also confirmed that fitting the "optional" 1/4 or 1/2 watt resistor into the handheld radio headphone circuit should solve the problem.

Cheers,

G
Garic Howles
040925

Ian Melville
Posts: 914
Joined: Mon Feb 11, 2008 8:21 pm

Re: Auto Mute with Sigtronics Sport 200 and Yaesu FTA550

Post by Ian Melville » Sun Sep 13, 2020 7:08 pm

Garic,
Test results in :)
I was able to reproduce your issue with the system wired as yours is without the 220 Ohm resistor.

Adding the resistor (225 Ohm in my case) gave an approximate equal balance in level between incormig radio traffic and intercom. That is as per the briefing sheets and Dino's advice. You do need to bump up the radios volume a few notches to compensate.

I dropped the resistance to 150 Ohms and feel this would be a low as you would want to go with partially muted intercom.

For anyone else reading this. The document, SPA-200_Yaesu_FTA-750_Inst.pdf, to follow is available from the Yaesu website. It is also applicable to the FTA550
Ian Melville
032644

garich
Posts: 8
Joined: Mon Jul 07, 2014 1:01 pm

Re: Auto Mute with Sigtronics Sport 200 and Yaesu FTA550

Post by garich » Tue Sep 15, 2020 3:01 pm

Hi Ian,

That's some very useful and time saving information.

Thank you so much.

We will go ahead with fitting a resistor as you described and see how we get on.

Many thanks,

Garic
Garic Howles
040925

Post Reply