My NAZA GPS is REPAIRED!!

[Gav]

:laugh:As some of you guys know (forum chat) I have been suspicious of my Naza gps since a mid air crash in Dec.  The GPS outer case was wrenched open a little but all I did was just re-set the case with some glue.   It worked on and off after that with it taking forever to get a sat lock. 
I resigned myself to thinking I would just have to buy another.  So opened up the GPS case again (more difficult this time with my added super glue)...noticed the gps antenna itself had 2 hairline cracks running through the ceramic.  Flexed it a little and sure enough the crack was running all the way through basically the antenna was in half.  It was toast.

Just desoldered the antenna and it fell appart - no chance of picking up anything in that state.   I was thinking of pinching the gps antenna from my wifes car which has an old style navigation system.  You know the type, the little external antenna sits on the dash behind the windscreen... but thought hmmm better not even though it never gets used anymore.   So I ordered a £6.36 inc vat GPS dielectric from RS Components.  collect on Monday.  Well for 6 quid it has to be worth a punt.  Otherwise 100 smackers for another Naza GPS module booohoohho  waaaaahahahaaaaa  >   :wallbash:

Will keep you posted if it works.  If it doesn';t then I will go sit in a dark room for a long time.

http://uk.rs-online.com/web/p/gps-antennas/7249075/?searchTerm=gps+dielectric&relevancy-data=636F3D3126696E3D4931384E44656661756C74266C753D656E266D6D3D6D61746368616C6C7061727469616C26706D3D5E5C442B5C735C442B2426706F3D3926736E3D592673743D4B4559574F52445F4D554C54495F414C504841267573743D677073206469656C6563747269632673633D592677633D4E4F4E4526




Also here';s the reason my gps got smashed

! No longer available

[johnrs]

be interesting to see if this works

[KK1W]

Sure looks like it should work. If the SMA connector snaps in I would think you';ll be fine. You said it was marginal with the smashed antenna, even if this one isn';t perfect it should be a lot better.

Looking though the .pdf spec sheet I noticed a predicted 5 MHz drop in center frequency when put in a radome. Makes me wonder if the ones being sold without a radome would work better if we put them in one. They also specified the gain figures with a 70mm ground plane under the antenna, FWTW.

The antenna bandwidth is pretty wide, so without a radome you';ll have lower gain and higher SWR (or return loss). Without the ground plane the gain will probably be lower and the pattern slightly different? I';ll have to talk with some of my other radio friends to get up to date on this stuff.

But my money is on it working just great 

[benchmark]

I will be interested in hearing if it works , i am afraid the naza firmware will not recognize it as firmware in general is written to recognize a particular GPS unit and there are hundred different ones out there , unless you find the exact same gps module that DJI uses.
Let is know the outcome.

[Gav]

I';m not sure I follow? 
I';m only replacing the patch antenna on the original module itself.

The exact same patch antenna is available in china but am using the rs components one as a possible  quick fix.

See how it goes.

[Gaza07]

I think it will work as the gps unit its self is still on the naza board your just changing the antenna and im not sure the naza gps which is only a ublox neo 6m can tell if its been changed,
I cant tell from the pictures if there is a small circuit under the antenna the active part ?
if there isnt then your going to just need to remove the active part from the replacement as it must be on the board with the gps module, I hope it all goes well Gav 

[benchmark]

I always assumed that the patch antennas were unique for any GPS units own internal algorithms for computing coordinates. Thats what i meant. If that particular algorithm is changed , the firmware cant recognize it. At least that is what immersionrc say about their EzOSD gps unit if its to be replaced. Like i said, i may be wrong or the gps antenna you bought may even be interchangeable with DJIs own model, let us know , i think its a good experiment considering the cheap price.

[KK1W]

From looking at the spec sheet it';s just a 50 ohm patch antenna. If the connector fits the rest of the NAZA GPS shouldn';t be able to tell the difference. That being said it will be good to see confirmation - thanks for being the guinea pig!

[Brian]

I hope this works as I';m always crashing!!

Brian

[Gav]

I hope this works ....

Brian

You and me both mate LOL

Can';t wait to collect the antenna and try....  pleeeeeease work 

[Gav]

OK earlier I fitted the replacement antenna - went outside and I got a sat lock within 30 seconds.  I could of jumped for joy when I saw the GREEN only flashing light.  Just this minute got back from a test flight too with good gps correction and position hold.  I also initiated a butt clenching failsafe RTH /RTL and it came back.  RESULT!



RS COMPNENTS part number 7249075

[Gaza07]

Excellent news Gav very well done I';m sure this will help others in the future 

[benchmark]

Wow, that is great news, i would have bet it wont work. I gotta save this thread inc ase i have to do likewise one day. Well done again 

[Gaza07]

There is a bookmark feature in the extras bit on the froum that will keep a bookmark to threads you want to keep 

Wow, that is great news, i would have bet it wont work. I gotta save this thread inc ase i have to do likewise one day. Well done again 

[Brian]

That is awesome news mate! I';ll be keeping this in my bookmarks in case the same thing happens to me!

Brian

[Smeagol]

Well done Gav ... don';t need it yet  but maybe ... just maybe ... 

[Gav]

This post is just for reference.  Below is a link to buy an exact gps antenna replacement (albeit pre mounted to a board with pig tail).  If you';re ok with ';diy repairs'; and don';t mind the risk of spending 20 quid or so for a diy fix, then this could also be an option (might be able to tease off the gps dielectric from the small board it is mounted on):

http://www.aliexpress.com/store/product/GPS-ANTENNA-connecting-wiht-module/606369_445451135.html

also hobbyking

http://www.hobbyking.com/hobbyking/store/__31135__NEO_6M_GPS_Module.html

[realpastaman]

Thanks GAV mine is also fixed after a Pile Driver Crash on the GPS!!!!!
[attachimg=1]

[blankers]

Gav,

Looking on the RS site they have 4 gps antennas ranging from £1.96 - £5.75 exc vat. They all look pretty much the same. Why did you choose the one you did ?

Would anything be gained by changing the existing 2mm antenna for a 4mm antenna ?
It';s bigger so must be better.....right ?

[Gav]

I went for a replacement as close as I could get, locally, to the smashed one.  I guess checking / comparing the spec of other antenna, will tell you if its better.  Check out
Acquisition & Tracking sensitivity.
:)
http://www.labsat.co.uk/index.php/en/applications/receiver-sensitivity-testing

Cheers
Gav

[realpastaman]

Have you seen these? I';ve just repaired a NAZA lite with one! at $10 thet are a bargin! Great quality and arrived really quickly.

http://www.ant-king.com/homeweb_en/catalog_detail.php?infoscatid=8&ifid=7