I wonder if it sees Mode C also.
It wouldn't be too difficult to receive also Mode-C with such a dongle, but unless you know the exact beam direction and interrogation timing you can't get a lot of information out of the transmission.
Are there many Mode-C only transponders left? Not around here, AFAIK
There are airfields, non radar equipped obviously, which have one of these boxes "around".
Biggin has something similar - a proper NATS radar feed that they aren't allowed to use ... officially (actually, rumour has it they will soon be allowed to use it to give a proper radar service).
It is absolutely invaluable - ATC can query dodgy position reports and altitudes, and have good warning of aircraft inbound. It seems to pick up Mode-S flight IDs as well - if the radio is busy and you can't get a word in edgeways they will often ask if you are on frequency as you pass 5 miles.
Are there many Mode-C only transponders left?
In the UK there is a sizeable community who have not upgraded, due to
The very few TMZs in the UK are Mode C, not Mode S 
You need Mode S for flying abroad, de facto, but most planes never do that. Maybe Le Touquet...
Also most of southern Europe seems to have ignored Mode S totally.
a proper NATS radar feed that they aren't allowed to use
Rumour has it that this costs £100k/year...
But Biggin pays Thames Radar a commercially confidential flat rate for the radar service - also reputed to cost some similar amount. If Biggin get radar, they won't need to use Thames anymore.
ATC can query dodgy position reports and altitudes, and have good warning of aircraft inbound
Exactly what I was told, but they can't let it be known overtly that they know "you" are lying about your position
Actually they would get a good result with a used TAS600 box off Ebay, hooked up to something to display it. That would show Mode A and C too. With N-regs they would also get the tail number.
Exactly what I was told, but they can't let it be known overtly that they know "you" are lying about your position
The usual phrase is "I can't see you in your reported position".
After quite a bit of debate, must've been 25 years ago, It was decided that no airspace in the US under 18,000 feet would require Mode S. So yes, there are quite a few Mode C transponders still operating - in most of the worlds light aircraft.
I would have calmer flying if I rarely saw another aircraft in flight - but operating from an airport with 650 operations per day, surrounded by other similar airports, it's not likely to be the case. We do have an occasional mid-air collision, perhaps one per decade locally, and it's interesting to conjecture why it isn't more often.
One answer is virtually all aircraft having Mode C, and all airports locally having Radar data piped in from a centralized Radar facility. Beyond that I think it is just a matter of accumulated experience, airspace problems got analyzed after every midair and changed if appropriate. It's not been a theoretical exercise, and the required infrastructure has been installed.
The usual phrase is "I can't see you in your reported position".
hmmmm, clever, very clever
London Info wouldn't be able to do that because everybody knows they are sitting in some place with no windows.
After quite a bit of debate, must've been 25 years ago, It was decided that no airspace in the US under 18,000 feet would require Mode S
But, the USA used the carrot of TIS to get people to adopt Mode S.
In Europe, carrots are not necessary. The population is very compliant 
But, the USA used the carrot of TIS to get people to adopt Mode S.
There was rumour this could be enabled in the UK for very little money - has anyone heard anything concrete?
I am looking at PowerFlarm and the website says
"In summary it detects: •other ADS-B equipped aircraft without PowerFLARM •other Mode-C/S XPDR equipped aircraft ( estimated range and real altitude difference but not direction) •other aircraft with normal FLARM compatible systems "
In Europe GA where there isnt much transmitting ADS-B, isnt the limitation descriibed above (where mode-C/S aircraft will only be indicated by their range and altitude, and not direction), really makign this no more effective than a ZAON MRX (the small device). I cant see how something like SkyDemon could display another aircraft equipped only with Mode C/S if it cant show the direction.
Thoughts?
I agree
If somebody built a FLARM box which does azimuth on Mode C/S targets, they would have a winner.
I suggested this to the PowerFLARM chief designer and he was completely uninterested.
I suggested this to the PowerFLARM chief designer and he was completely uninterested.
I presume you talked to the Butterfly Avionics guys at AERO. They are not the designers, the PowerFLARM box is from Switzerland, done by FLARM. Butterfly does sales and support.
I find the box to be remarkably good with the latest firmware. Today it showed all traffic. The other day it warned me of a glider that got really close and the biggest surprise was last week when I had an ADS-B target (a triangle at an exact position) and this turned out to be a microlight!
My PowerFLARM is connected to a yoke mounted Garmin 695 and sends data via TIS. The Garmin 695 does an excellent job at displaying the targets. With the latest firmware it got its own traffic screen. My 695 is hooked up to the audiopanel and I get aural traffic warnings.
