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#### Aerowerx

##### Well-Known Member
My old cell phone broke, so yesterday I went out and upgraded to a Motorola Droid Maxx smartphone. Also got Better Half one as an anniversary present (she is supporting my aviation habit!).

So I have been sitting here sipping my coffee and looking at aviation apps for android.

Just came across a $10 USD ADS-B receiver app, which requires the Avare app. Both apps are free, with the$10 price tag for the hardware receiver, which I guess is a USB plug in originally for European TV reception.

Being a ham radio operator and frustrated radio astronomer (I have an aversion to starving---not many paying jobs in that area:gig, I was quite interested in the little USB receiver, and may investigate it further for other non-aviation apps.

I know there are some old threads on smartphone apps here on HBA, but was also wondering what the latest/best apps were for flight instruments and navigation.

#### Aerowerx

##### Well-Known Member
UPDATE: It appears that the $10 price may be outdated. I just found the recommended receiver on Amazon, and it is$21.95 USD. May be cheaper elsewhere, though.

#### BBerson

##### Well-Known Member
HBA Supporter
Doesn't need to be certified or have a long range. If it works in class G airspace, it would be better than flying with nothing as others could see the target.

I figure the drone guys will develop something cheap.

#### Vigilant1

##### Well-Known Member
Doesn't need to be certified or have a long range. If it works in class G airspace, it would be better than flying with nothing as others could see the target.

I figure the drone guys will develop something cheap.
I'm guessing the FAA will frown on any ADS-B Out transmissions that don't come from equipment they have blessed. The whole ADS-B architecture depends on accurate data from the participants.
Sure, there's no requirement to put out >any< info today in uncontrolled airspace, but I think in their paradigm they would prefer no info (and a continuance of see and avoid in VMC) than info that doesn't meet their standards (with the required inspections, calibration, etc). Protecting the ADS-B program so that the transition can continue may be as important as protecting aviators, to the degree the goals are not the same.

#### BBerson

##### Well-Known Member
HBA Supporter
I'm guessing the FAA will frown on any ADS-B Out transmissions that don't come from equipment they have blessed.
I don't know if the FAA approves experimental or hand held or portable transmitters.
Could be compliance with FCC is required.
The quality of the signal should be needed for a Drone or anything, I think.
What rules apply to Homebuilt kit VHF radios?

#### Aerowerx

##### Well-Known Member
Could be compliance with FCC is required.
Certainly, but I think you would have to satisfy both agencies.

What rules apply to Homebuilt kit VHF radios?
In the USA, you can build anything you want so long as it is a receiver and does not cause undue interference with other devices. (Yes, receivers do radiate.)

As far as transmitters are concerned, you can build anything you want. You just cant use it unless you have a valid amateur radio license and the transmitter meets those technical requirements and frequency ranges. Or it must be type certified by the FCC for use outside the amateur bands.

As for the cheap ADS-B receiver, I don't understand all of what they were saying on the web site, but apparently it works only for 1090 MHz (what the big boys use at higher altitudes???), and 980 MHz is used for lower altitudes (or on the ground). So it's usefulness might be limited in experimental aircraft.

#### fredoyster

##### Well-Known Member
This is part of my education that stopped decades ago when proficiency in Morse Code was required for amateur radio. It my understanding (and an admittedly rather ignorant one) that these kits could be assembled by anyone, but only legally used by someone with an amateur radio license. It's my further understanding that for a consumer product the FCC only cares that it not radiate interference. This seems to be a fairly easy bar to clear with the FCC. Getting the same device type certified with the FAA requires complete testing per RTCA DO-160G or similar.

Maybe someone here that is as nuts about radio as we are about aircraft can clarify this?
Any radiator, intentional or otherwise, must comply with FCC rules, which go far beyond not creating interference. Below a certain radiated level, you're only required to do your own testing, self-certification and marking. This permits ramp testers (except within 100 kHz of 121.5) to be sold under Part 15 without further approval, for instance. For anything practical for interacting with ATC you need to get FCC equipment authorization. It's not as difficult as meeting FAA TSO, but still a lot of hoops to jump through.

For some radios, like comm radios and most nav receivers, no FAA approval is required for VFR installations in experimental a/c. There are TSO'd radios and ones that aren't. Yaesu makes a handheld that has com and nav with VOR/LOC/GS (!) and GPS (but without an aviation database) for $400, or$200 without the GPS and GS. You have to dig in to each individual rule to figure out what's required. ADS-B out, either Mode S (1090ES, basically additional data both broadcast and in your transponder return) or UAT (978 MHz) as I read it requires both the transmitter and WAAS GPS to be made under the relevant TSO, which in turn calls for compliance with a raft of RTCA requirements and FAA oversight. DO-160 is not so difficult, for low altitude unpressurized aircraft, but the software checking requirements (DO-178 and friends) are not simple -- and then add those requirements to the Minimum Operational Performance requirements for the specific device.

#### Aerowerx

##### Well-Known Member
... send your completed kit back to Jim Weir for checkout before you could operate it.
Yes, that has been done. But very few companies actually did that and they usually didn't last too long (or that product didn't last). I also wonder how many builders actually sent their's back.

I remember that the Heathkit Company made a strobe light kit for general aviation. You were supposed to send it back so they could check it over, per FAA requirements, before installing it in your certified aircraft. Again, how many actually did?

#### Rob_O

##### Member
Half of the price difference between those two Yaesu radios is the lithium battery pack you must buy to get the added gs and gps features. Bad way to sell batteries as a good percentage of these radios will likely wind up hardwired to an experimental aircraft. Not real sure I would want to do an ILS landing on a matchbook size screen though.

#### aeromike49

##### Well-Known Member
I have been doing research on this subject as I plan on buying a GRT Mini X and connecting with the TRIG transponder to have ADS B output on the 1090 Frequency. From what I read the position information for now - until 2020 - for EXPERIMENTAL aircraft only does not have to be a certified unit - the ADS B code that the unit puts out will be ZERO indicating that it is not a certified unit which ATC can then use this code to reject the signal if and when they so choose - the transponder does have to be certified (TSO) and has to be re-certified every 24 months regardless of experimental or certified aircraft it is installed in. So what it looks like is the use of an uncertified position (GPS) unit will be allowed on Experimental aircraft until the 2020 date. The transponder must be a TSO unit regardless of aircraft type or date. ADS B in you can get that anyway you want as it is receive only.

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