Portable Transponder ?
Thread Starter

Joined: Jan 2008
Aviation Qualifications: ATPL
Posts: 38
Likes: 63
From: The Smaller Antipode
Portable Transponder ?
I guess if I Gargle it, or Wiki it I can find some answers, but briefly ... does anyone know of a 'portable' transponder that I can use in a Druine Turbulent (no generated electrical power ) microlight ?
I fly off an "unattended" airfield, i.e. no ATC in Class G airspace, but we have a mandatory broadcast zone for the benefit of the Dash 8 Air New Zealand commuter service four or five times a day, so no NORDO a/c are permitted, and I have rigged up a handheld radio with a fixed aerial and spare battery, but the zone is also Transponder Mandatory down to 2,000 ft. agl. so that Air NZ can see us on their TACAS gear, but their pilots are putting pressure on our CAA to lower the TM section down to ground level.
Unless I can find a small transponder to work off a battery, similar to my radio, then I will be permanently grounded.
Thanks.
I fly off an "unattended" airfield, i.e. no ATC in Class G airspace, but we have a mandatory broadcast zone for the benefit of the Dash 8 Air New Zealand commuter service four or five times a day, so no NORDO a/c are permitted, and I have rigged up a handheld radio with a fixed aerial and spare battery, but the zone is also Transponder Mandatory down to 2,000 ft. agl. so that Air NZ can see us on their TACAS gear, but their pilots are putting pressure on our CAA to lower the TM section down to ground level.
Unless I can find a small transponder to work off a battery, similar to my radio, then I will be permanently grounded.
Thanks.
Joined: Jul 2010
Posts: 2,807
Likes: 10
From: Ansião (PT)
There are some being marketed especially towards gliders, should be equally useable for you. You'll have to carry some kind of battery, though, which may be a lot of weight. Ah, I see you are already carrying a battery for the radio, well, if it is juicy enough it can supply the transponder, too. When not transmitting, i.e. when not interrogated, power draw is quite limited, at least for the newer generation solid state transponders.
Last edited by Jan Olieslagers; 6th March 2016 at 06:47.
Joined: Jul 2007
Posts: 1,158
Likes: 62
From: 51.50N 1W (ish)
A German company did one for the military, but not available to the GA market. A number of people do boxes with a transponder in, normally including a battery, for balloon pilots. Try the balloon community.
It wouldn't be difficult to fit a TRIG TT21 in a Turb, plus a 10AH LiFePO4 battery pack (or SLA if you don't fill the tank/go on a diet etc.).
You wouldn't even need to have the control unit on the panel, just leave it on 7000, 1200 or whatever is the generic VFR squawk locally.
It wouldn't be difficult to fit a TRIG TT21 in a Turb, plus a 10AH LiFePO4 battery pack (or SLA if you don't fill the tank/go on a diet etc.).
You wouldn't even need to have the control unit on the panel, just leave it on 7000, 1200 or whatever is the generic VFR squawk locally.

Joined: Apr 2000
Posts: 264
Likes: 4
From: south of 60N
Murg
you could try one of these
Transponder | Dittel Avionik
There was some talk about NZ aviation regulators sponsering a low power mode S transponder for the gliding world some years ago but i am not sure if it came to anything.
you could try one of these
Transponder | Dittel Avionik
There was some talk about NZ aviation regulators sponsering a low power mode S transponder for the gliding world some years ago but i am not sure if it came to anything.
Thread Starter

Joined: Jan 2008
Aviation Qualifications: ATPL
Posts: 38
Likes: 63
From: The Smaller Antipode
Murg
you could try one of these
Transponder | Dittel Avionik
There was some talk about NZ aviation regulators sponsering a low power mode S transponder for the gliding world some years ago but i am not sure if it came to anything.
you could try one of these
Transponder | Dittel Avionik
There was some talk about NZ aviation regulators sponsering a low power mode S transponder for the gliding world some years ago but i am not sure if it came to anything.
Never thought of balloons ! Surely they are big enough to See and Avoid !! and don't usually lift off active airfields ( do they ? ) but will enquire.

Joined: Jul 2002
Posts: 179
Likes: 0
From: essex
Joined: Feb 2016
Posts: 165
Likes: 0
From: Greater London Area
Could somebody please explain to me the concept of a "portable" transponder?
A transponder nowadays means almost everywhere a Mode-S XPDR. Part of the technology is the transmission of the registration of the aircraft, so "portable" does not make sense to me, as the current technology is bound to the registration and hence aircraft anyways. Yes, you can carry some, but why should you? Low power does make sense and many of the modern solid state ones are (i.e. a TT31 does pull only 0,5A when active, so very little batteries would drive that sufficient - 12V/2Ah is good for 4 hours and is what, 300 grams?), but portable?
A transponder nowadays means almost everywhere a Mode-S XPDR. Part of the technology is the transmission of the registration of the aircraft, so "portable" does not make sense to me, as the current technology is bound to the registration and hence aircraft anyways. Yes, you can carry some, but why should you? Low power does make sense and many of the modern solid state ones are (i.e. a TT31 does pull only 0,5A when active, so very little batteries would drive that sufficient - 12V/2Ah is good for 4 hours and is what, 300 grams?), but portable?

Joined: Oct 2006
Posts: 896
Likes: 0
From: Strathaven Airfield
Simple.
A portable, self-contained low-power , squawk 7000 unit will tell anyone else equipped with radar, TCAS or whatever that there is something around that doesn't want to be hit by another aircraft, and probably doesn't want to hit them either!
No-one really cares who the pilot is, what the G-REGG of the aircraft is or anything else. Just that someone is in the air.
And if it could be the price of an iphone, all the better.
There are people flying around in aircraft that cost less than some drones!
And if you have a share in an aircraft, that often costs well below the price of any currently available transponder (and its installation).
So price is important. And safety is important. Keeping it simple makes it work.
So why not put the three together?
Ah! I forgot! This is aviation we are talking about.
A portable, self-contained low-power , squawk 7000 unit will tell anyone else equipped with radar, TCAS or whatever that there is something around that doesn't want to be hit by another aircraft, and probably doesn't want to hit them either!
No-one really cares who the pilot is, what the G-REGG of the aircraft is or anything else. Just that someone is in the air.
And if it could be the price of an iphone, all the better.
There are people flying around in aircraft that cost less than some drones!
And if you have a share in an aircraft, that often costs well below the price of any currently available transponder (and its installation).
So price is important. And safety is important. Keeping it simple makes it work.
So why not put the three together?
Ah! I forgot! This is aviation we are talking about.
Joined: Aug 2003
Posts: 1,579
Likes: 0
From: Not a million miles from EGTF
Simple.
A portable, self-contained low-power , squawk 7000 unit will tell anyone else equipped with radar, TCAS or whatever that there is something around that doesn't want to be hit by another aircraft, and probably doesn't want to hit them either!
No-one really cares who the pilot is, what the G-REGG of the aircraft is or anything else. Just that someone is in the air.
And if it could be the price of an iphone, all the better.
There are people flying around in aircraft that cost less than some drones!
And if you have a share in an aircraft, that often costs well below the price of any currently available transponder (and its installation).
So price is important. And safety is important. Keeping it simple makes it work.
So why not put the three together?
Ah! I forgot! This is aviation we are talking about.
A portable, self-contained low-power , squawk 7000 unit will tell anyone else equipped with radar, TCAS or whatever that there is something around that doesn't want to be hit by another aircraft, and probably doesn't want to hit them either!
No-one really cares who the pilot is, what the G-REGG of the aircraft is or anything else. Just that someone is in the air.
And if it could be the price of an iphone, all the better.
There are people flying around in aircraft that cost less than some drones!
And if you have a share in an aircraft, that often costs well below the price of any currently available transponder (and its installation).
So price is important. And safety is important. Keeping it simple makes it work.
So why not put the three together?
Ah! I forgot! This is aviation we are talking about.
Last one I think was around 2009/10, but I think that the idea was quietly dropped, as the manufacturers wouldn't proceed unless the Mode S requirement was mandated.
Last edited by robin; 8th March 2016 at 08:07. Reason: typo

Joined: Oct 2006
Posts: 896
Likes: 0
From: Strathaven Airfield
Oh yes, forgot about the other reason for portability:
We have 32-odd aircraft in our hangars. Very rare more than half are flying at any one time.
So, as we do with fuel trolley for instance, maybe an idea to have some "club" transponders. Split/shares the cost.
Do we need registrations - well, yes, you can reprogramme. But, again, this makes more complex.
Keep it simple, make it cheap.
Think: what do we want things to do?
Unfortunately, all these committees are filled with people of a different mindset to simple leisure flyers.
We have 32-odd aircraft in our hangars. Very rare more than half are flying at any one time.
So, as we do with fuel trolley for instance, maybe an idea to have some "club" transponders. Split/shares the cost.
Do we need registrations - well, yes, you can reprogramme. But, again, this makes more complex.
Keep it simple, make it cheap.
Think: what do we want things to do?
Unfortunately, all these committees are filled with people of a different mindset to simple leisure flyers.

Joined: Jul 2002
Posts: 179
Likes: 0
From: essex
Home
Kinetic did build a portable transponder many years ago know as the LAST devise.
This looked like a large handheld GPS ..
They tried to get it approved by the CAA, when the CAA had to approve these things now done by EASA. But they ran it to problems with the device range being only about 50 miles due to output wattage being low.
Kinetic did build a portable transponder many years ago know as the LAST devise.
This looked like a large handheld GPS ..
They tried to get it approved by the CAA, when the CAA had to approve these things now done by EASA. But they ran it to problems with the device range being only about 50 miles due to output wattage being low.




