Primarily for general aviation discussion, but other aviation topics are also welcome.
johnm wrote:Did you do the bit in bold ??

Hold the FUNC key down whilst pressing the on button.

FUNC then moves forward
START/STOP moves backwards
CRSR key moves from field to field within a page

Find the ADDRESS HEX entry and make sure it matches your hex code (which you can get from G-INFO)

Find the FLT ID entry and change it from 'PWR-UP ENTRY' to 'CONFIG ENTRY' and put in your reg without any spaces (eg GABCD)

Also, after I’ve done all that is there a need to effectively ‘enter’ it, or do I just press FUNC to move off that page?
By johnm
You can move off the page and then power off the transponder to save the entries. I'm fairly sure that the GTX 328 will show call sign if entered correctly in the same way that the GTX330 does.
Right. HEX is correct.


And reg is correct (my blacking out).


So, I can only assume it doesn’t transmit in the same way as a more modern Mode S, hence the very straight line in my track (I can’t possibly fly that straight) and the Twitter comment from FR24.

I’ll just leave it as it is I think.
TheFarmer wrote:Maybe it’s this?

I think the above is the answer.

A friend has one in his aeroplane - pretty sure the GTX328 is only Mode S and not capable of ADSB-out from GPS (like the GTX330 is) which is why he only sometimes shows up on the likes of FR24 and then without the detail you get with a properly configured ADSB-out/GPS signal.

But then Im in no way an authority on this stuff... though Id like to lean if anyone feels like posting here!!

Regards, SD..
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By Cub
You are using a transponder that does not do ADS-B out and trying to track the emission via a ‘toy’ app.

If you switch it off you will be operating illegally (SERA) because the installation is perfectly detectable and interoperable with proper ground based ATM surveillance systems and with certified ACAS systems, delivering a significant safety net to yourself and other airspace users. However, without ADS-B out detection via a wide range of GA interoperable ‘devices’ and apps is not guaranteed.

Kind of epitomises in one thread the emissions debate on this forum for the past few years.
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By derekf
G-INFO advanced search on hex id will provide all details including registration number
For non-G reg a/c some of the popular flight tracking sites also can provide the information (via google)
The Farmer, as written above, the Garmin GTX-328 is a basic Mode-S transponder without Extended Squitter (GTX-330ES required for that), The GTX-328, when correctly configured, will emit your aircraft's 24-bit address in the non-ES (elementary) Mode-S interrogation responses. Apps such as Flight Radar 24 are not guaranteed to pick up these basic Mode-S transmissions, as for such transmissions, they rely on a technique known as multilateration, whereby multiple ground receivers (typically 5+) are required to find the geographical position of the Mode-S elementary return. It may well be that you were in an area where this MLAT requirement was not met.

Iceman 8)
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Iceman wrote:The Farmer, have a look at page 8 of the following document. The unit has to be configured at installation to enable the user to alter the Flight ID. It may well be that your unit is not configured correctly.

Iceman 8)

Thanks iceman.

I think it’s configured as well as it can be and the age of the unit / MLAT thing is the reason it’s not giving my reg. The Hex is correctly entered and a FR24 search with my reg comes up with my flights, so it’s not confusing it with another aircraft.
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