lost AP74

[rvg8tor]

Hopefully someone has had this and knows how to fix it. This may or may not be a problem since I am transmitting in my garage.

My system is D180 EFIS, HS34, AP74 Garmin 430W and Garmin 240 intercom, radio 2 is ICOM A210.

When I transmit on the A210 my AP74 Lights come on and flash and I get AP74 lost alert if the transmission is long enough. I can get the AP74 back. It does not seem to effect the HS34 DSAB connection.

The problem seems to be associated with the antenna on the left side of the belly, what ever radio I hook up to that antenna, I get the AP74 to drop. My twisted pair of wires from the pitch servo run on this side and the pitch and roll wires join at a terminal block near the base of this antenna, I did this so I only had to run one set of wires though the wing spar area

Maybe this is all due to being in a basement level garage.

 

[dynonsupport]

It's basically affecting DSAB, period, and isn't going to be related to the fact that you're in your garage. To confirm that it's interference, you might try disconnecting the wires that go to the pitch servo, if you can. Unfortunately, you may need to relocate those DSAB wires a bit further away from the antenna. We may also have another solution for you, though I'm not sure about that. Give us a call at 425-402-0433 and mention that you've been asked to call about this.

 

[rvg8tor]

Problem solved. I narrowed things down to the AP74 and HS34. As I transmitted I would watch the DSAB network and could see what dropped first. It was the AP74, if the transmission was longer the HS34 would drop. I removed the AP74 from the DSAB network and did not have an issue so I figured it must be that wire.

I took the panel out to get to the AP74 wire. When I wired the AP74 I used a twisted pair that was in my D180 harness labeled "not used". I did not cut the wires, instead I looped the wire down the main wire bundle that runs behind the panel. I removed this loop and cut the wire shorter to make a more direct run to my DSAB hub and this did not go behind the radio stack.

I also removed a wire from my Safety Trim harness that was not being used, it was a power wire for a trim indicator, this too was behind the radio stack.

After installing things again and several radio checks on many different frequencies I have no DSAB issues anymore. And I am still transmitting in the garage. I am actually able to get a radio check with the center control in may area, hill in back has the repeater I think.

One small issue I have now is there is a small whine in the intercom what the AP74 back lighting is on (when control is set to dimmer setting background lights come on).

I hope this helps someone else.

 

[Brantel]

I think all of us experience the noise from the AP74, HS34 dimmer....Dynon has not said much about it. At least one guy on here was working on some solutions for this but I have not heard from him in a while.

Dynon, what say you on the dimmer noise from the AP74 and HS34???

 

[dynonsupport]

We've recently noticed some noise from the dimmer in the modules as well, but in flying tests that noise wasn't perceptible, so we hadn't considered it a big issue. Are you able to hear the noise once the engine's running?