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Uavionix Tailbeacon....not for M4

Posted: Sat Nov 23, 2019 4:28 pm
by ragwing8
Received the UAvionix Tailbeacon and tried to install it. No way that thing will fit in the rudder. The diameter of the unit is maybe .020 less that the frame mount for the current position light. Even if I could force it in, the taper of the fabric would stop it within a couple inches of insertion.

Looking for alternatives.....

Anyone with an M4 and Whelen wing tip strobe install the Skybeacon? I’ve got the combo nav/whelen strobe.

Btw, my M4 is the early version. Don’t know if rudder frames dimensions are different on late model M4.

Posted: Sun Nov 24, 2019 2:21 am
by G-MAWL
Hi Ragwing, is there a possibility of making a nylon ring spacer and longer screws to prvent it reaching the fabric ?
I have a vested interest in asking !!

Derek

Posted: Sun Nov 24, 2019 4:22 am
by Akafrank
Check the previous skybeacon message on the forum, lots of information. I was unable to install it in my M5 but others were successful. I ended up putting in a Garmin 335.

Here's an alternative:

https://www.aircraftspruce.com/catalog/ ... x0QAvD_BwE

Ralph
Akafrank

Posted: Sun Nov 24, 2019 7:55 am
by Mog
Check the thread AKFrank posted, but long and short, the tail beacon fit my M4 just fine.

Posted: Sun Nov 24, 2019 2:26 pm
by ragwing8
I found where the interference is on mine. There is a “bossâ€￾ on the lower side of the rudder frame light socket ring. Looks like just sloppy manufacturing, but that boss extends up into the socket ring on the bottom probably a /32 of an inch. I could insert the beacon on the 35 degree angle (really stretching the fabric), but it would absolutely not rotate, as the bottom of the beacon housing hits that boss.

Unable to post a picture.

Being mine is a very early model, Ser. #26 it may be the later rudder frames are better made,[/img]

Posted: Wed Dec 04, 2019 3:11 pm
by ragwing8
Got the Tailbeacon installed okay. Wound up tapping the screw holes for the light so I could use the screws supplied. Fits snug and secure.

Then the fun began.

During the set up, the app would not connect with the Tailbeacon WiFi using my Android phone (Motorola).

Put the app in my iPad mini and it connects no problem.

After a couple days trying to get it to work, uavionix is sending a replacement.

It will just not see the transponder signal. (KT76A), although Houston approach control picks it up perfect.

Tech support has had me adjust the transponder minimum threshold several times, to no effect. It has to be done while the transponder is being queried by ATC (or with a ground test box).

That meant I had to fly to Houston and land, use the app on the ramp where there is radar coverage..... It never saw the code.

Finally I got tired of going to KIWS to configure it, I adjusted the stall speed of the unit to 140 knots, so the WiFi would not cut out while airborne ( in radar coverage where I live in podunk) and tried several different transponder threshold settings while airborne. Still no luck.
FYI, the WiFi chip shits off at 100kts gps speed, according to uavionix tech support, so I stayed at 80.

Pretty frustrated at this point. Trevor at uavionix tech support has been as helpful as could be, so with so much time already invested in this thing, I’m gonna give it one more try when they send a replacement.

My mechanic had the same issue with a C172 on the SKYBEACON, gave up and advised me against using the beacon. Maybe I shoulda taken his advice.

More later.

Posted: Wed Dec 04, 2019 6:46 pm
by Mog
Wonder if this is associated with a particular transponder. I was nervous that I would have issues as well, but my install was smooth as silk and has not presented a problem so far.

Posted: Wed Dec 04, 2019 7:30 pm
by Dale Smith
Mog, curious what transponder are you running?

Posted: Wed Dec 04, 2019 10:28 pm
by ragwing8
Mine is a KT76A. I’ve wondered if it could be the transponder, but if Tracon can see it and it returns are correct, it seems unlikely.

I just had it recertified two months ago.

Posted: Thu Dec 05, 2019 3:13 am
by Akafrank
I'm curious how you have the unit grounded. I had a long talk with uAvionics about my install problem and they mentioned to also be aware of grounding problems. They said while the hinge provides an adaquate ground for the light, sometimes it causes problems for the tail beacon communication. In anticipation, I ran a hard ground wire to the rudder control arm which should provide a solid connection to the frame.

BTW, the unit can be made to fit the Maule Rudder. A spacer may be required and significant adjustment to the opening required depending on how the fabric had been applied.

Let us know the final determination.

Ralph

Akafrank

Posted: Thu Dec 05, 2019 5:42 am
by ragwing8
Mine is grounded through the mount. The wire is left loose , per their advice.

I sanded/ filed away some of the fabric lapped over the frame where it mounts.

Were they specific about what kind of comm problems?

I’d like to know specifics of how you routed that wire, as others probably would also.

Posted: Thu Dec 05, 2019 7:04 am
by andy
I come at the ground issue as a radio technician. I know that uAvionix says that the ground through the two rudder hinges is adequate, but my experience tells me otherwise. The rudder hinges are not perfectly flat against the frame tabs as the rudder moves so that's the first point where a ground problem could occur. The contact surfaces get dirty and wear as the rudder moves. The hinges are usually lubricated with non-conducting grease, which picks up dirt over time, increasing the likelihood of a poor ground.

Modern computerized avionics are very sensitive to ground problems and often reboot if the ground is intermittent. I experienced this first hand with my JPI EDM-800 engine analyzer years ago. I ended up running a dedicated ground wire all the way to the alternator at JPI's recommendation and it solved the problem.

The hinge ground is perfectly fine for a tail light and I'm sure that's why Maule didn't run a separate ground wire. If the ground becomes intermittent, you can just clean off the hinges when you land. Since you don't use the navigation lights during the day, most people never notice if the tail light is intermittent. Running a piece of avionics that is sensitive to ground faults is a different story.

It's a pain to run another wire to the tubing on the rudder frame but the good news is that you don't have to run it all the way to the TailBeacon socket. Any solid connection to the chrome-moly steel tubing that goes to the socket should be fine. You just need to make sure that the socket has a good electrical connection to the tubing and that the ground wire has a good connection to the same tubing.

Posted: Thu Dec 05, 2019 7:10 am
by Mog
I have a Narco AT50. Keep in mind that the beacon does not read your squawk code the same way radar does. If it did then it could get confused when flying around other aircraft. The Sky/Tailbeacon listen for electrical noise in the wiring you supply it with. Through that noise the unit can pickup pulses from the transponder and decode them as a squawk code. So the unit would not work correctly if it was independently powered by say a battery.

Posted: Thu Dec 05, 2019 2:10 pm
by Akafrank
To ground the tail beacon, I ran a wire from the remote avionics rack behind the baggage compartment to the tail following the positive thru the fabric and attached the wire to the rudder yoke that is bolted to the bottom of the rudder. Although the bolt sets on the fabric, I believe the bolt contacting the yoke which is inside the steel tube makes a good ground.

At the beacon end, the Maule drawing actually shows a stud inside the tail welded to the top tube. It is not there on my aircraft so I planned on drilling a hole thru the top about an inch and a half back to accept a #6 screw to attach the ground directly to the frame. I never got to that point as I decided too much was required to open the hole to accept the tail beacon and installed a new Garmin 335 transponder instead.

It has been 6 months since I talked with uAvionics but as I recall they mentioned the unit uses the ground for communication which is why it must be a good clean ground. The hinges may work fine or they might not and I know of no way to check.

The tail beacon is a good inexpensive way to meet the 2020 requirement if it actually is plug and play, every aircraft is unique.

Ralph
Akafrank

Posted: Fri Dec 06, 2019 7:55 am
by Andy Young
Just curious: given the struggles some people seem to be having getting the Tailbeacon to work, why not just go with the Skybeacon (wingtip version)? That’s what I’m using, and it was quite painless to install and set up.