Ideas About Next Generation FA Antenna


#1

Expecting Next Generation FA Antenna with built-in Filter and RF Amplifier (dc power on coax).

The Filter & Amplifier should be individual snap-fit cartridges, like two(2) AA batteries, snap fitting into the battery holder. The Amp and Filter should each be replaceable by a blank pass-through cartridge. This will give easy installation/removal of Filter and/or Amplifier, and enable users to easily tailor their system according to their needs.

Any comments/suggestions?


#2

Rather than a blank pass-through, eliminate the transition all together. Snap on to add. Keep It Simple and minimize the number of transitions/failure points… :slight_smile:

Cheers!
LitterBug


#3

Given our high-level goal of broad ADS-B/MLAT coverage, we’re putting our hardware efforts towards enabling a lot of good sites rather than a few great ones. Don’t get me wrong, we think the huge numbers being put up in the “personal distance best” thread are fantastic and I’m hoping to join the thread when we upgrade the setup on top of our office, but this is not where maximizing our worldwide coverage is going to come from.

We recognize it’s ideal to locate the amp at the antenna, but the cost and complexity of doing so makes it less appealing for us to expend our efforts on. An antenna with a proprietary cartridge based integrated filter/amp misses most of our hardware development criteria and goals:

  • Using industry standards for interchangeability/interoperability
  • Targeting low complexity improvements (individual bolt-on or direct replacement parts)
  • Dropping prices, or keeping them at existing low levels
  • Improving worldwide distribution of quality ADS-B hardware

Putting the amp on the dongle allowed us to get amps in the hands of thousands of users “for free” to the extent our dongle is no more expensive than competing non-amped dongles. I don’t think a power inserter/discrete amp/DC blocker/etc kit delivering better performance than our on-dongle amp could be done for twice the price of our dongle, much less “free”.

Users looking to locate the filter/amp at the antenna can do so with the Pro Stick using either a long USB run, or also colocating the RPi and using Power over Ethernet. I believe these options are comparable in price and complexity to DC power on coax setups.

If you want to guess what we’re going to do next, consider the criteria/goals listed above and take a look at what we’ve done in the past:

  • First an outdoor antenna, at a third the price of the DPD or BS1105.

  • Second an ADS-B optimized, broadly available, low cost filter. We wanted to do a SAW filter for size reasons, but couldn’t get the cost/performance where we wanted them, so we accepted the larger size of the cavity filter.

  • And most recently, a dongle with a “free” amp and less-flaky connector.

I’d like to see our antennas halve in price. I’d like to see our filters be smaller and $5. I’d like to see our dongles retail at $10.90 (or $9.78). But we haven’t figured out how to do any of those yet.*

I will tell you two things our next hardware development won’t be:

  • Cables, since they’re already broadly available at low prices with a variety of connectors/adapters
  • An antenna with a proprietary cartridge based integration of filter and/or amp
  • I would also like a pony. For the office.**
    ** And a robot to clean up after it.

#4

Mduell,
Very well stated, and I especially agree with the last two!

Cheers!
LitterBug


#5

Inexpensive USB Dongle with Amp(not locked to a few frequencies like ModeS, UAT and FLARM) - Check
Inexpensive Antenna and Dual band Antenna - check.
SOC MB 10 times faster then available at the beginning of last year(not by FA) - check.
Ingenious Software support for MLAT without requiring special hardware - check
Complete setup, RPI3,SD,Ant,Dongle,Filter (less cables and box) for about $US120 - check
Make your own Antenna for less.
idiot proof SD card build - check
Runs for a few dollars a month in power costs. I have an older TV that uses more power in standby mode than an RPI3. check
I think it is pretty good value for money.
(I have a setup, 3ft off the ground on the side of the house, that received over 275,000 position hits today. I am in a busy area).

The inline/Masthead amp is fraught with issues:-
temperature variations, including possible direct sunlight.
waterproof and warranty for this.
Which waterproof connectors to use. N, SMA, F, etc?
Which inline power to use. BiasT ~5V or Satellite injector power ~12V?

These are appreciations from someone that has an airspy, DPD Antenna, LMR400 UF Coax and just ordered a Ceramic filter Hab Amp


#6

Agreed, this is realistic and important goal.

If you want to guess what we’re going to do next, consider the criteria/goals listed above and take a look at what we’ve done in the past:

  • First an outdoor antenna, at a third the price of the DPD or BS1105.
  • Second an ADS-B optimized, broadly available, low cost filter. We wanted to do a SAW filter for size reasons, but couldn’t get the cost/performance where we wanted them, so we accepted the larger size of the cavity filter.
  • And most recently, a dongle with a “free” amp and less-flaky connector.

I appreciate FA has done a lot of excellent work. Thanks.

I’d like to see our antennas halve in price. I’d like to see our filters be smaller and $5. I’d like to see our dongles retail at $10.90 (or $9.78). But we haven’t figured out how to do any of those yet.*

This is great. Thanks.

  • I would also like a pony. For the office.**
    ** And a robot to clean up after it.

boohoo… I also want these. :smiley:
.


#7

I’d like to see an inline amp for the masthead - connectors to match FA antenna, and a 5v power injector (USB connector) to match same with SMA connectors to match FA filter etc.


#8

“the Pro Stick using either a long USB run, or also colocating the RPi and using Power over Ethernet.” is, IMO the way to go.

Some considerations might be:

Take the existing FA Pro board out of the case, apply aluminum heatsinks to the critical parts, then seal the boards using either epoxy, elastomer, or other waterproofing material, leaving only the heatsinks exposed. The USB connector can be made moisture resistant by using a boot of some rubber or appropriate elastic material, or simply applying electrician dielectric grease to the connection.

An RPi, Orange Pi, or similar can be treated the same way, with heatsinks on the critical components and then seal the board with above described method and unused ports with rubber protectors.

48v POE to a 5v/Ethernet converter is desirable as the converter can take a wide range of voltage from 10v to 48v and make it 5v. That means voltage drop over relatively long CAT5 runs becomes insignificant to the resulting voltage and current feed for the computer and stick. Wall wart style POE injectors are $12, and the voltage converter/splitter is $12.

The FA Filter is quite effective, and can be integrated into the stack forthwith.

The antenna can be added to the stack and be a J-pole, coaxial dipole, collinear, or coaxial collinear, all of which will fit in a piece of PVC pipe along with the electronics at the bottom, and a weatherproof RJ45 jack at the bottom. Add some appropriately angled venting to the sides with a drip hole at the bottom, and this should withstand most climates.

Outdoor rated/direct burial/UV safe/waterproof CAT5 is about $0.07/ft. in bulk or $25 for 100’ with connectors. ($0.25/ft.)

Off the shelf, this can be built for around $100. In mass production, a combined package could be much lower. No coax, no jumpers, lots of planes.

If you’ll send me the electronics pieces, I’ll be happy to put it all together for a demo :slight_smile:


#9

Thank you for your stance on proprietary hardware this is something I like to hear.
I like the option of being able to change things up and not have to rely on FlightAware to make what I want/need.

As far as what I would like to see?
A cheaper dedicated 978MHz antenna for around the price of the 1090MHz only antenna not one which covers 1090MHz as well at twice the cost.


#10

With two separate dvb-t dongles for 978 & 1090, one needs two separate antennas as well.
Under this condition, two single frequency low cost antennas are better than two high cost dual frequency antennas.


#11

We got the extra 2db gain on the dual band with the idea that people wanting both frequencies would split it (which should be -3db if I recall my EE101) and end up at about the same place as a dedicated antenna.

I’m personally kind of surprised at the level of interest in 978 on the ground, given that 978 TIS-B is just what’s on 1090 ADS-B and 978 FIS-B is no better than weather products you can find online for free. That leaves the bug smashers with 978 ADS-B as the reason to do 978, and there’s generally not much equipage unless you happen to be near one of the training fleets that did 978.


#12

UAT does nothing to assist FA tracking. No reason to pursue that or tailor gear for it. Makes sense.


#13

At least for me bug smashers are more interesting to observe than straight flying heavy bodies.

How do you figure?
UAT tracks can be sent to FA through dump1090/PiAware.


#14

Maybe I need to give it another shot. last time I tried dump978 I got nothing.


#15

@k5ted
uat2esnt converts UAT to MODE S which can then be sent to dump1090.
github.com/mutability/dump978#u … b-messages


#16

I still only get 45-50 “real” adsb planes a day on UAT which is a very small drop in the bucket compared to the 3000+ a day for 1090. I don’t count the TIS-B broadcasts as “real” planes. Maybe as we get closer to the 2020 deadline or when the price of the UAT systems get cheaper we will begin to see significant UAT traffic. Or maybe when Amazon starts shipping via drones with onboard transponders: http://www.aviationsafetymagazine.com/issues/34_16/features/ADS-B-For-Small-Drones_10936-1.html

Cheers!
LitterBug

Or possibly google: [https://www.flightglobal.com/news/articles/google-targets-low-cost-ads-b-out-avionics-market-410473/](https://www.flightglobal.com/news/articles/google-targets-low-cost-ads-b-out-avionics-market-410473/)

#17

I agree there is very little UAT traffic at the moment. My antenna is still inside and I only see an aircraft or two a day. I hope to see considerably more when I setup the outside antenna(I have the dual band FA Antenna but may splurge for the DPD one)

The 2020 mandate should help a lot, however, note that in the US, cars have had unleaded petrol/gas for 40 years and the aviation community is still balking at its use. We have seen the same issue with decent drivers licence security, NYS drivers nearly lost the ability to use their licences as IDs to get on commercial aircraft this year. It had to be extended again, despite being told about the issue 10 years ago.

The promise of UAT was 1090 like position reporting with the carrot of free “realtime” weather and traffic via TIS-B and ADS-R. It was also supposed to be much cheaper than the 1090 equipment. I believe that we are getting there, however, it is expensive and time consuming to certify the equipment, especially considering it can only be used in the U.S. Anyone thinking of flying International will need to consider 1090.

A low power version, similar the the EU FLARM, for gliders, would also be nice. It seems silly to use a different system, however, I understand the power limitations for gliders.

There are many aircraft that don’t fly in Class A airspace (above FL180 in the U.S.) so don’t require the full 1090 setup. There are very very helicopters that fly that high. Few GA aircraft fly that high. I am sure that there are many “puddle jumpers” that don’t fly that high too. They would be worth tracking, even if FA is not that interested in them.

Personally, if I could afford it(I don’t even have an aircraft), I would like dual in/out UAT and 1090 for safety and awareness reasons. Free access to weather and other FIS info would be great. I know that it won’t help with non-electrical aircraft, but they may not even have Mode A/C so radar may not help much either. I also like the SAR aspect. Being able to have an accurate last known position would mean that searches for people like Steve Fossett wouldn’t take 9 months to find the AC.


#18

The 1090/978 UAS (drone) transponder lives:
http://www.uavionix.com/product-2/

From this perspective, a massive number of localized short range receivers makes a lot of sense due to the low flight level < 500 feet. Long range receivers are not going to be picking up the low level flights.

Cheers!
LitterBug


#19

Another interesting DOC related to Google’s plans for UAS:
.pdf

Cheers!
LitterBug


#20

I expect the puddle jumpers will equip with 1090, not 978.

Lots of aircraft that can’t reach FL180 are doing 1090 anyways.