UAVIONIX SKYBEACON TAILBEACON Freqecy Drift

2nd505th

Pre-takeoff checklist
Joined
Apr 11, 2018
Messages
108
Display Name

Display name:
2nd505th
I've had two avionic techs say they will not install the UAVIONIX SKYBEACON ADS-B products. One described a frequency drift issue, the other one called it a cavity. That some altitudes are not reporting correctly. Anyone heard of this?
 
First, you do not need an avionics shop to do the install...A&P can install...signed off by IA. Ask your IA for help...
 
Please report back on what they are talking about. When I had my old cavity tube transponder, I had an altitude encoder that would not report altitudes above 9k accurately, pre-ADS-B. You sure you heard right that it was the Skybeacon which was giving problems? I am skeptical based on the way you said it.
 
Doesn’t sound very accurate technically.

Altitude comes from your encoder and the sky beacon’s GPS separately. Two different things and GPS altitude doesn’t drift.

Frequency wise, it’s just a 978 MHz transmitter for data. Not exactly a difficulty in RF engineering design these days, and nothing whatsoever to do with altitude reporting.

Would love to hear more, but almost afraid of what these geniuses came up with. If they have test data showing a problem, I’m sure uAvionics would love to see it, too.

Debating whether to add an eye roll prior to hearing more information about what they (think they) saw.
 
Altitude comes from your encoder and the sky beacon’s GPS separately.
The sky beacon picks up the altitude (and squawk code) as the transponder sends it via electrical noise on the power wire so both are sending exactly the same information.
 
Doesn’t sound very accurate technically.

Altitude comes from your encoder and the sky beacon’s GPS separately. Two different things and GPS altitude doesn’t drift.

It doesn't use GPS altitude. It has its own static pressure sensor.
 
The sky beacon picks up the altitude (and squawk code) as the transponder sends it via electrical noise on the power wire so both are sending exactly the same information.

Fair enough. I assume by “electrical noise” they just receive the RF from the existing transponder.

I assumed the little thing had a GPS also but if it doesn’t, okay.

If something is “off frequency” in these setups it is going to be the 40 year old POS transponder that should have been replaced. LOL.
 
Fair enough. I assume by “electrical noise” they just receive the RF from the existing transponder.
Garmin has a patent on that - hence the work around using noise on the power wire.As the transponder sends 1s and 0s, there apparently are noise spikes on the power.

I assumed the little thing had a GPS also but if it doesn’t, okay.
It does - but it is required to transmit the same baro altitude as the transponder.
(just double checked - 91-227 D: transmits both the barometric and geometric (which I assume is GPS) altitudes)

If something is “off frequency” in these setups it is going to be the 40 year old POS transponder that should have been replaced. LOL.
That.
 
Garmin has a patent on that - hence the work around using noise on the power wire.As the transponder sends 1s and 0s, there apparently are noise spikes on the power.

Garmin patented receiving transponders. LOL. They would.

It does - but it is required to transmit the same baro altitude as the transponder.
(just double checked - 91-227 D: transmits both the barometric and geometric (which I assume is GPS) altitudes).

Yeah I was going on knowing that both needed to be transmitted. :)
 
Yes this is in regard to the UVAVIONIX wing and tail beacon products. Which should not be called tailbeacon as it replaces the white position light. In any regard, from talking with Uvavionix they said they work well with the old tube transponders. He also said they do not interrogate the transponder directly like Garmin, rather wait for data that is collected in the air during a radar sweep. It would seem to me that if your transponder is off frequency, then ATC is not going to see you correctly regardless of ADSB out.

But another question, it almost seems that this Uvavionix device is acting as a middle man. It sends transponder code, altitude from your encoder. So no added value there. And it also sends your tail number. What is the value added besides that? It took a radar sweep just to get your tail number? What am I missing? Of course I understand that pilots with ADS-B can see you whether you are near radar or in the middle of nowhere.
 
Yes this is in regard to the UVAVIONIX wing and tail beacon products. Which should not be called tailbeacon as it replaces the white position light. In any regard, from talking with Uvavionix they said they work well with the old tube transponders. He also said they do not interrogate the transponder directly like Garmin, rather wait for data that is collected in the air during a radar sweep. It would seem to me that if your transponder is off frequency, then ATC is not going to see you correctly regardless of ADSB out.

But another question, it almost seems that this Uvavionix device is acting as a middle man. It sends transponder code, altitude from your encoder. So no added value there. And it also sends your tail number. What is the value added besides that? It took a radar sweep just to get your tail number? What am I missing? Of course I understand that pilots with ADS-B can see you whether you are near radar or in the middle of nowhere.

Their products are a lower cost solution that provides your aircraft with ADS-B out capability so that you can fly into rule airspace. Also they can be installed by an A&P and signed off by an IA without the need of going to a dedicated avionics shop. This was the reason I bought mine as the wait times for any avionics shops in my area was around 6 months, and since I am based at a Class C airport, that would have effectively grounded me until I became ADS-B out compliant. So now I can continue to fly, that is if free time/weather would allow me...
 
My understanding was that ADSB out must send something ever N seconds. So it's hard to believe it is reliant on a ATC radar sweeping it.
 
Just FYI, We've been running the Skybeacon for maybe 6 months now and 0 complaints from the Feds or anyone else doing aerial photography in the heart of the Bravo here in Dallas. If there's a problem with the unit, I'm sure we'd be hearing about it already.
 
OK after doing a little reading (lazy me) it appears ATC, TRACON, etc can always see you through a network of satellites, ground stations and bouncing off of other ADS-B equipped aircraft. They can see you, your tail number, your GPS altitude. But a radar sweep which normally gathers the transponder and encoder data adds to the data sent by ADS-B. At least that's the way I'm seeing it now. But then I don't always get it.
 
I don’t see a problem. It was approved for use and works fine, and especially with the ease of installation. (I don’t have one, but it’s because I was adding WAAS NavCom capability to the plane and just made sense to replace my transponder).
 
Their products are a lower cost solution that provides your aircraft with ADS-B out capability so that you can fly into rule airspace. Also they can be installed by an A&P and signed off by an IA without the need of going to a dedicated avionics shop. This was the reason I bought mine as the wait times for any avionics shops in my area was around 6 months, and since I am based at a Class C airport, that would have effectively grounded me until I became ADS-B out compliant. So now I can continue to fly, that is if free time/weather would allow me...
My home field is near a C and the Chicago mode C veil, so to not have it would have meant detours in many flight directions. The skybeacon for me was a no brainer: $1500 total (after rebate), quick install, and it works fine with my old transponder. I figure if the transponder goes out, I can buy replacements on Ebay for $75, or with a 8130 for $300. Just did a check, there are over 100 of my model transponder for sale there right now.
 
But another question, it almost seems that this Uvavionix device is acting as a middle man. It sends transponder code, altitude from your encoder. So no added value there. And it also sends your tail number. What is the value added besides that? It took a radar sweep just to get your tail number? What am I missing? Of course I understand that pilots with ADS-B can see you whether you are near radar or in the middle of nowhere.
It's Next Gen for crying out loud! This is what all ADS-B units do. ATC gets the same information that they got via radar and this lets them do amazing Next Gen things. Amazing.
 
OK after doing a little reading (lazy me) it appears ATC, TRACON, etc can always see you through a network of satellites, ground stations and bouncing off of other ADS-B equipped aircraft. They can see you, your tail number, your GPS altitude. But a radar sweep which normally gathers the transponder and encoder data adds to the data sent by ADS-B. At least that's the way I'm seeing it now. But then I don't always get it.

ATC will see primary radar via bouncing the radar signal off your airplane and secondary radar via a transponder. With mode C, the transponder can return pressure altitude. A mode S transponder will return the call sign and ICAO aircraft identifier. ADS-B includes the same information provided by a mode S transponder, that is the N number and the ICAO aircraft identifier plus the squawk code, the pressure altitude, and the ident feature. In addition a form of GPS altitude, velocity information, latitude-longitude, integrity and accuracy data, and an indication of the ADS-B In capabilities on board the aircraft. For ADS-B Out units that obtain data from the transponder, they do it in a variety of ways, some use a serial interface, some have a 1090 MHz receiver and sniff the response from an interrogation (TCAS, TAS, or ground radar) or via sniffing the voltage fluctuations on the electrical buss. Those that use one of the sniffing techniques rely on more than just ground stations to interrogate the transponder, they also can use replies to TCAS or TAS aircraft in the vicinity or overhead.
 
My understanding was that ADSB out must send something ever N seconds. So it's hard to believe it is reliant on a ATC radar sweeping it.

ADS-B broadcasts position updates once per second. Depending on where you are, your altitude, the type and number of radar systems interrogating you this can vary between a few seconds and a dozen seconds. Transponders also reply to other interrogations from TCAS and TAS systems in other aircraft.
 
I had no interest in one at all. How do you know form the cockpit the fool thing is even working?
 
I had no interest in one at all. How do you know form the cockpit the fool thing is even working?
How do you know form the cockpit any fool adsb-out solution is even working?
 
How do you know form the cockpit any fool adsb-out solution is even working?
The one on my panel has lights and shows the transponder code. It could break without me knowing, but at least I know it has power and is trying to squawk the right code. Also, fishing out your phone to change transponder codes while you have a handful of airplane seems at best ludicrous.
 
I am sure those shops just want to sell you the $6000 fix so they can make more money! They probably are not Skybeacon dealers and do not want to deal with only making a hour labor!
We did one on my buddies 170 last week and it was less than 1 hour!
 
As far as the local TRACON is concerned, they're perfectly okay with non ADSB aircraft in their airspace provided they have a transponder and mode C. They have everything they need to know to do their job. I suspect that a non ADSB aircraft contacting the local Class C approach control won't be turned away but I haven't had the occasion to test this theory. I have heard a local flight school without ADSB in their aircraft are continuing to operate at a Class D airport.
 
Also, fishing out your phone to change transponder codes while you have a handful of airplane seems at best ludicrous.
Why would you have to do that? Just change the squawk on your transponder.
 
The one on my panel has lights and shows the transponder code. It could break without me knowing, but at least I know it has power and is trying to squawk the right code. Also, fishing out your phone to change transponder codes while you have a handful of airplane seems at best ludicrous.
That does seem ludicrous. It’s also not at all how it works. Don't let that stop you from telling people that do know how it works how dumb they are for using them.
 
Last edited:
fishing out your phone to change transponder codes while you have a handful of airplane seems at best ludicrous.

You misunderstand the Iphone connection to the Skybeacon/Tailbeacon. The App is only used for the initial setup and can only be used on the ground within the first 5 minutes from power up. Once set up there is never a need to have a smartphone around again. I have been using my Tailbeacon for sometime without any problems.
 
The one on my panel has lights and shows the transponder code. It could break without me knowing, but at least I know it has power and is trying to squawk the right code. Also, fishing out your phone to change transponder codes while you have a handful of airplane seems at best ludicrous.

You have absolutely NO idea what you're talking about.
 
I had no interest in one at all. How do you know form the cockpit the fool thing is even working?
Form your point of view, how do you know your fool keyboard is working? Form my point of view, its not.

As far as the Skybeacon, I can see it lit up, just like your fool transponder. I can also look on Foreflight, under the category of "own ship" and not only see it working, I can see how well its working, nic, nac, and the padiwack.
 
I have heard a local flight school without ADSB in their aircraft are continuing to operate at a Class D airport.

Yes, as long as the Delta airport is not within a mode C veil or other prohibited airspace.
 
The one on my panel has lights and shows the transponder code. It could break without me knowing, but at least I know it has power and is trying to squawk the right code. Also, fishing out your phone to change transponder codes while you have a handful of airplane seems at best ludicrous.
D7871CA1-5791-4076-800B-2BADF009C2F3.jpeg
 
I see nothing wrong with a Skybeacon it it suits your needs and budget. It was my understanding that the blade antenna has an LED that blinks to warn you if there is a malfunction. Your legacy transponder/encoder works same as always.

Of course, you will only see this LED on a high wing aircraft.
 
As a low wing flier, I have also added a step to my pre-taxi checklist to verify my SkyBeacon is OK by connecting to it via wifi on either my phone or my ipad and checking status in the app.
 
As a low wing flier, I have also added a step to my pre-taxi checklist to verify my SkyBeacon is OK by connecting to it via wifi on either my phone or my ipad and checking status in the app.
Prior to this, Did you call up the tower and ask if your mode c was working?

I could care less if it’s working and the people that do will let me know if it’s not.
 
It would seem to me that if your transponder is off frequency, then ATC is not going to see you correctly regardless of ADSB out.
Not true! Even if your transponder return isn't received, ATC sees your ADS-B return via the network of 800+ ADS-B transceivers on cell towers.
But another question: it almost seems that this uAvionix device is acting as a middleman. It sends transponder code, altitude from your encoder. So no added value there.
Well... except that other aircraft, and ATC, can receive that, even if you're below radar coverage.
And it also sends your tail number. What is the value added besides that? It took a radar sweep just to get your tail number?
No, the unit knows your tail number. Your transponder does not.
What am I missing? Of course, I understand that pilots with ADS-B can see you whether you are near radar or in the middle of nowhere.
 
Back
Top