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Thread Tools | Display Modes |
#11
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New Transponder for us
On Dec 8, 2:48*pm, jcarlyle wrote:
What Darryl said. You might like to know that the avionics technician who did my VFR transponder checks went to his computer and got the proper ICAO code from the FAA. The reason is the "S" in Mode S stands for selective, and they want to be darn sure ATC is broadcasting to the proper aircraft. All seems very reasonable and I would have no intention of using an incorrect ICAO address. Did your technician also check that the transmitted registration number, which seems to be a separate data entry on the TT21, was correct? Andy |
#12
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New Transponder for us
Yes, he did.
-John On Dec 8, 5:38 pm, Andy wrote: All seems very reasonable and I would have no intention of using an incorrect ICAO address. Did your technician also check that the transmitted registration number, which seems to be a separate data entry on the TT21, was correct? Andy |
#13
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New Transponder for us
On Dec 9, 7:18*am, Darryl Ramm wrote:
On Dec 8, 12:03*pm, jcarlyle wrote: For two reasons: *(1) it costs less to perform the biannual inspection, and (2) you aren't broadcasting your tail number to the Feds. Of course, you'll only get a 10 year life out of it... -John On Dec 8, 2:54 pm, Andy wrote: Why would anyone buy a mode C transponder when for only a little more one can buy a mode S unit? Andy Actually the 10 year life is not completely accurate, even if I agree a bit with probably the sentiment behind it. I just don't want any glider pilots with Mode C transponders to think their transponders have an abslute hard limit where they stop being useful in 10 years. Mode C transponders are usable it the USA well beyond 10 years - but to meet the 2020 ADS-B data-out carriage requirement (a requirement for power aircraft in similar airspace as transponders are required now) you would need to add a UAT transmitter or replace the transponder with a Mode S with 1090ES data-out. Right now its impractical from a cost, STC paperwork hassle (on non-experimental) and final -B rev compliance requirements on many products, to add ADS- B data-out to most light aircraft or gliders but you can install a Trig TT21 and in future update the firmware and add the ADS-B data-out GPS. How current aircraft owners manage the transition to the 2020 ADS-B data-out mandate will be interesting to see - i.e. whether Mode C equipped aircraft add UAT devices or swap out their transponders to get new Mode S units with 1090ES data-out. I expect many will take the transponder upgrade route since it is a chance to refresh older transponders which they still need to carry (in may owner aircraft) and older transponders can become a maintenance liability, so why not refresh both in one box? For newer Mode C transponders there exists more of an argument to add a UAT device. In the glider community in the USA with PowerFLARM looking like important and popular technology Mode S 1090ES data-out is a better technology to consider than UAT data-out. Darryl Don't forget, mode S will use a lot less power under non-trivial interrogation... From soggy Oz, ]See ya, Dave |
#14
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New Transponder for us
On Dec 8, 4:18*pm, Dave Nadler wrote:
On Dec 9, 7:18*am, Darryl Ramm wrote: On Dec 8, 12:03*pm, jcarlyle wrote: For two reasons: *(1) it costs less to perform the biannual inspection, and (2) you aren't broadcasting your tail number to the Feds. Of course, you'll only get a 10 year life out of it... -John On Dec 8, 2:54 pm, Andy wrote: Why would anyone buy a mode C transponder when for only a little more one can buy a mode S unit? Andy Actually the 10 year life is not completely accurate, even if I agree a bit with probably the sentiment behind it. I just don't want any glider pilots with Mode C transponders to think their transponders have an abslute hard limit where they stop being useful in 10 years. Mode C transponders are usable it the USA well beyond 10 years - but to meet the 2020 ADS-B data-out carriage requirement (a requirement for power aircraft in similar airspace as transponders are required now) you would need to add a UAT transmitter or replace the transponder with a Mode S with 1090ES data-out. Right now its impractical from a cost, STC paperwork hassle (on non-experimental) and final -B rev compliance requirements on many products, to add ADS- B data-out to most light aircraft or gliders but you can install a Trig TT21 and in future update the firmware and add the ADS-B data-out GPS. How current aircraft owners manage the transition to the 2020 ADS-B data-out mandate will be interesting to see - i.e. whether Mode C equipped aircraft add UAT devices or swap out their transponders to get new Mode S units with 1090ES data-out. I expect many will take the transponder upgrade route since it is a chance to refresh older transponders which they still need to carry (in may owner aircraft) and older transponders can become a maintenance liability, so why not refresh both in one box? For newer Mode C transponders there exists more of an argument to add a UAT device. In the glider community in the USA with PowerFLARM looking like important and popular technology Mode S 1090ES data-out is a better technology to consider than UAT data-out. Darryl Don't forget, mode S will use a lot less power under non-trivial interrogation... From soggy Oz, ]See ya, Dave Dave is correct that Mode S transponders will consume less power in some environments where they are being interrogated as a Mode S transponder since they do not see the extra Mode A/C interrogations (at least not those from a Mode S capable interrogator) and so need to transmit fewer replies than a Mode C transponder. However that does *not* get close to explaining the apparent high power consumption (1.1 Amp!!) of this Mode C transponder vs. the Trig Mode S transponder. The exact details of power consumption in different situations for SSR radar depends on details of the ATCRBS ground interrogator. The transponder will still likely get hit by multiple interrogations per sweep and the individual transmission from the Mode S transponder may well take more power than that a Mode C transmission. The power required for a Mode A/C transmission depends on the squawk code (==pulse pattern) but the power required for the Mode S data-packet does not change like this. In complex TCAS I and II environments the Mode S transponder will see fewer interrogations but even a Mode C transponder will only reply to a small fraction of the realtively high interrogation rate of a TCAS system since TCAS uses the "whisper-shout" trick to cause Mode C transponders within a certain distance range to reply. Its all that TCAS Mode C interrogation and replies from some of the Mode C transponders that is a bandwidth hog (and why goign to Mode S only in the USA might have been a good idea to support ADS-B 1090ES). Mode S is much more elegant. TCAS discovers the Mode S transponder by its acquisition squitter (advertising it is there without needing to be interrogated) and the TCAS interrogator can interrogate Mode S transponders uniquely without using the whisper-shout hack. If being interrogated by a Mode C only interrogator (e.g. by GA aircraftTCAD/TAS systems (which have traditionally not supported Mode S interrogations) then the Mode S transponder will transmit Mode A/C replies without any of the Mode S stuff. Darryl |
#15
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New Transponder for us
On 12/8/2010 4:51 PM, Darryl Ramm wrote:
However that does *not* get close to explaining the apparent high power consumption (1.1 Amp!!) of this Mode C transponder vs. the Trig Mode S transponder. According to the brochure I downloaded, the remote version of the unit only requires 200 ma, instead of 500 (still at 28 volts). That's still pretty high for a version without the encoder, but it makes me wonder where the 300 ma is going. Someone could call the company to find out, but really, I see little value in it when the Trig is so good. If you want to save some money, offer to buy a used Becker for, say, $1000-$1200, and get one from someone that's thinking of upgrading to a Trig. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) |
#16
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New Transponder for us
Someone could call the company to find out, but really, I see little
value in it when the Trig is so good. If you want to save some money, offer to buy a used Becker for, say, $1000-$1200, and get one from someone that's thinking of upgrading to a Trig. I'm just waiting for Trig to produce a transceiver too. |
#17
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New Transponder for us
On Dec 8, 6:59*pm, Eric Greenwell wrote:
On 12/8/2010 4:51 PM, Darryl Ramm wrote: However that does *not* get close to explaining the apparent high power consumption (1.1 Amp!!) of this Mode C transponder vs. the Trig Mode S transponder. According to the brochure I downloaded, the remote version of the unit only requires 200 ma, instead of 500 (still at 28 volts). That's still pretty high for a version without the encoder, but it makes me wonder where the 300 ma is going. Someone could call the company to find out, but really, I see little value in it when the Trig is so good. If you want to save some money, offer to buy a used Becker for, say, $1000-$1200, and get one from someone that's thinking of upgrading to a Trig. -- Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me) Either Sandia is quoting numbers for an encoder with heater full on (unusual to do so), or they have an inefficient encoder design or their control head draws a surprising large amount of power (for something with an OLED display), or some combination of all of that. A good rough number for steady state consumption for an ACK-30 encoder (what most of us with Mode C transponders in gliders use today) is a bit over 60mA @ 12VDC without the heater on. Heater full on they can draw 400mA @ 12VDC (luckily the heater should not be on often in usual use - but if you are flying in wave especially make sure the encoder box is insulated and protected from drafts). But even then even if you were compete nuts and wanted to spend money on a Mode C transponder today the headless version of this transponder is still not an option until somebody has a controller that can control it. BTW the heater in the encoder built into the Trig TT21/22 kicks in starting at 4C down to -25C where it is full on. At its peak it consumes 1.7 Watts (= 140mA @ 12VDC). Very impressive numbers. Data is from Trig engineering. I have a pair of very nice electrical heated boot insoles that I brought for wave flying and they consume almost the same as the spec on this Sandia transponder implies it does at 12VDC. Possible since I have 2 x 18Ah batteries, a engine driven generator, and a large solar panel in my motor glider... but still if I'm going to just absolutely burn power for the hell of it its going to be for important stuff like keeping my feet warm not to run this junk. Darryl |
#18
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New Transponder for us
On Dec 8, 1:48*pm, jcarlyle wrote:
What Darryl said. You might like to know that the avionics technician who did my VFR transponder checks went to his computer and got the proper ICAO code from the FAA. The reason is the "S" in Mode S stands for selective, and they want to be darn sure ATC is broadcasting to the proper aircraft. I was being tongue in cheek with my previous post. There's no reason, given the price and low power draw of the Trig TT21, that anyone should even consider buying anything else right now (unless they're replacing an existing transponder with the same type). -John On Dec 8, 3:37 pm, Andy wrote: As to broadcasting the tail number *- the TT21 installation menus allow the aircraft ICAO code and the registration to be set but I don't think there is an equipment requirement for them to be set. *In other words I think it will work if the defaults are left unchanged. Is there any regulation that requires a mode S transponder to transmit that data in US?- Hide quoted text - - Show quoted text - Price is the reason $400 to $500 less than the Trig Mode C. Richard www.craggyaero.com |
#19
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New Transponder for us
On Dec 9, 7:38*am, Richard wrote:
On Dec 8, 1:48*pm, jcarlyle wrote: What Darryl said. You might like to know that the avionics technician who did my VFR transponder checks went to his computer and got the proper ICAO code from the FAA. The reason is the "S" in Mode S stands for selective, and they want to be darn sure ATC is broadcasting to the proper aircraft. I was being tongue in cheek with my previous post. There's no reason, given the price and low power draw of the Trig TT21, that anyone should even consider buying anything else right now (unless they're replacing an existing transponder with the same type). -John On Dec 8, 3:37 pm, Andy wrote: As to broadcasting the tail number *- the TT21 installation menus allow the aircraft ICAO code and the registration to be set but I don't think there is an equipment requirement for them to be set. *In other words I think it will work if the defaults are left unchanged. Is there any regulation that requires a mode S transponder to transmit that data in US?- Hide quoted text - - Show quoted text - Price is the reason *$400 to $500 less than the Trig Mode C. Richardwww.craggyaero.com Trig does not make a "Mode C" transponder. Darryl |
#20
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New Transponder for us
On Dec 9, 7:46*am, Darryl Ramm wrote:
On Dec 9, 7:38*am, Richard wrote: On Dec 8, 1:48*pm, jcarlyle wrote: What Darryl said. You might like to know that the avionics technician who did my VFR transponder checks went to his computer and got the proper ICAO code from the FAA. The reason is the "S" in Mode S stands for selective, and they want to be darn sure ATC is broadcasting to the proper aircraft. I was being tongue in cheek with my previous post. There's no reason, given the price and low power draw of the Trig TT21, that anyone should even consider buying anything else right now (unless they're replacing an existing transponder with the same type). -John On Dec 8, 3:37 pm, Andy wrote: As to broadcasting the tail number *- the TT21 installation menus allow the aircraft ICAO code and the registration to be set but I don't think there is an equipment requirement for them to be set. *In other words I think it will work if the defaults are left unchanged.. Is there any regulation that requires a mode S transponder to transmit that data in US?- Hide quoted text - - Show quoted text - Price is the reason *$400 to $500 less than the Trig Mode C. Richardwww.craggyaero.com Trig does not make a "Mode C" transponder. Darryl- Hide quoted text - - Show quoted text - Sorry I agree on the Mode S tell the other vendor to correct his web site. Trig TT21 Class 2 Mode C Transponder with Built-in Altitude Encoder $2095 If you compare to the 35,000' $700 to $800 Less Richard www.craggyaero.com |
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