GPS antenna repairs

[JussiH]

So, you ripped the u.fl connector of your GPS antenna or need a longer wire on there...?

Here is a method to replace the antenna wire, using a normal Soldering iron and some Chipquik lowmelt desoldering alloy. If you can solder, its very easy to do, and does not require special skills or tools (apart from the chipquik alloy, of course) It can also be done with traditional hotair rework methods.

If you are very careful, I think it should also be possible to lift the antenna cover with a hotair gun that is normally used for paint-stripping. But if you venture into that, make sure you dont accidentally desolder the filter components underneath the cover or overheat the whole antenna...

http://www.digikey.dk/product-detail/en ... ND/1164267
or
http://www.digikey.dk/product-detail/en ... -ND/304148

I am not gonna go into details about how to work with chipquik, but here is a video:
http://www.youtube.com/watch?v=7kyaz4Zrd78

Stuff you will need:

SMA -> u.fl pigtail from some Ebay vendor - cut off the SMA end:

Apply the chipquik to one side of the cover, heat up and lift/bend it up so you can access the pads underneath:

Remove the old wire and clean up pads with desoldering braid or use the method suggested by chipquik (cotton swabs and isopropyl alcohol):

Cut off the SMA end of your pigtail, and remove the shield and insulation like this:

Solder new wire in place:

Clean the pads for solder and flux residue with desoldering braid and alcohol. Bend cover back in place and solder it in place:

Done!

Keep the wire lenghts as short as possible! The attenuation for the 1.13 mm cable is on the order of 1.5-2db per meter at 1575.42 MHz. Lenghts up top 15-20 cm should not be a problem...

[LPR]

Jussi

Thanks for the good tutorial on GPS cables. I plan to build a one foot long connecting cable for my GPS antenna. I'll buy one off ebay and I know were to find some ChipQuik.

Larry

[epyonxero]

Are there u.fl extension cables that dont require soldering? Like a u.fl female to u.fl male.

[JussiH]

[Max]

Thanks Jussi, nice writeup!

Question: does changing the connector length affect the antenna gain? And if so, does anyone know the numbers involved? eg. how long can it be w/out noticeable negative effects.

-Max

[Kisssys]

My lead is 4 times the length of what comes on the antenna with not noticeable change in performance. I think I looked at the charts and it wouldn't be over a .5 db by adding 10cm.