R

rv8pilot

Member
Hi Guys

Want to hear if I am the only one with this problem on the australian radio
X-COM 760 installed in my RV8 the problem is every time I press the mike button the radio opens both mikes (pilot and pass.) which means that there is a lot off noise in the transmission. this happens both from the front and rear seat.
We have removed the radio from the plane and made a complete new wiring on the work table just to be sure the plane was wired correctly,but result was the same
appriciate any help
jorn moller
OY-RVS RV8 o-360/fixed
255 hours and still smiling every time
 
xcom

Do you have the 3 position switch installed that turns off the intercom, isolates the rear passenger or completely enables the rear passenger?

I think I have a sympton of the same problem when the switch isn't in Intercom Off. If it's in either "on" position, I think the rear passenger is sometimes able to transmit. I decided I could live with that. I'm just getting out of phase 1 so I haven't taken any passengers up. These are just observations made during the installation and initial checkout.

On the other hand, I have been able to completely lock out all the buttons and knobs on the radio. Not even the power button would do anything. I also think my radio sometimes transmits relatively weakly and has short reception. It seems to have good days and bad days in this department. I was told that the software upgrade that's available on their website and which I haven't downloaded/installed might because there's some new software to address some secondary oscillator issue...

Have you noticed anything similar?
 
hi lucky
Thanks for the reply,for your problem I cant say that I noticed anything off that kind my radio is fairly new,so it proberly is updated (delivered may 2006)
I will install a new switch to see if I can live with it
Jorn Moller
 
mic gain?

Hi Jorn,

Is it possible that the mic gain for the passenger is set too sensitively? In any case, I'd contact the guys in Australia to get their feedback.
 
hi Mikey
Well the guys down under mailed us and called us idiots,and told us to wire the radio per plans ,we checked again and took the radio out and rewired in in the shop,same problem,and for 5 weeks they have not answered any mail,
my radio guru is living off installing radio gear in aeroplanes every day,so evrything is checked and then checked again,seems there is a software problem in the radio,and no easy solution,Will we see you at Hoganas in sweden????
sincerly Jorn
 
Radio squawk

This might be totally irrelevant, but I'll offer it as a straw to grasp.

As a novice builder, I made a very basic mistake when I wired my Garmin 250XL through the PS Engineering intercom. I had run all my control stick wires (including push-to-talk) into a simple terminal block mounted under the floor. That way if I ever needed to unhook the stick I wouldn't have to remove or cut any of the panel wires; Simply unscrew the wires from the terminal and lift the stick out.

Unfortunately, I ran one short of terminals to hook wires to. So, thinking that the front stick PTT and rear stick PTT could share a common circuit, I wired both PTT lines to the same terminal. What happened in real use was that the PTT microphone function worked only when the headset was plugged into the rear headset jack -- no microphone function from the front jack. It appears that the PS Engineering intercom requires separate circuits for each jack. Once I removed one of the PTT wires from the common terminal block, both front and rear PTT worked as they were supposed to.

I offer this on the off-chance that you may have front and rear wires sharing a common connection somewhere.

Hope the explanation is not too confusing.

Chris
 
Headset issue?

This may be a completely separate problem than you're experiencing, but I thought I'd throw it out just in case.

I had an issue with my XCOM that prevented the passenger mic from muting. Their customer service rep was not very helpful. However, after a few email exchanges, he put me in contact with the radio's designer, who is a very nice fellow.

It turns out they saved a few components in the radio by combining the mic bias circuit with the mic muting circuit. The el-cheapo headset I had connected to the passenger position wasn't drawing enough bias current, and the result was a perpetual hot mic.

Solution: use a different headset (David Clark worked for me), or put a resistor across the mic jack. For a resistor value, I'd start with something in the 2.2k to 10k range (based on TLAR). The optimum value would depend on the headset you're using; a higher value would be less likely to mute the mic, a lower value will tend to attenuate the mic output.

Good luck,
Paige
 
possible solution

:confused:I too have an XCOM and am just in the middle of wiring it in my airplane. Is it possible that you have somehow wired the Co-Pilot PTT into a momentary switch in order to take advantage of the frequency change option using this wire? I'll find out next week if I've done it correctly, but am also worried about this "option" that might cause a double transmit situation.
Ron
RV-4 flying in 10 days (I hope)
 
From XCOM Avionics

The radio in question in the above correspondence has turned up to our business today.

Now I'm not saying there is nothing wrong with the radio but when a customer grinds the four corners of the front face with a bench grinder and then expects the radio to continue working I don't know what to say.

Sometimes, it is not the fault of the equipment but the actions of the owner. In all our correspondence with the owner he is never once mentioned grinding the radio corners down. If you can imagine the heat this would inject into the radio is probably enough to desolder something not to mention the vibration caused by running the radio on a bench grinder.

Please note: do not grind the corners of your radio with a bench grinder if you will not fit into your panel for whatever reason !!

Thanks Michael Coates XCOM Avionics
 
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