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external antenna

Posted: 20 Jan 2019 10:05
by moidabord

Could you please help me about one thing ?

I need to connect an external antenna to this card :


What I did : (cf. schema above)
  1. Solder the core of external antenna to the GREEN hole.
  2. Solder the shield of the antenna to the two RED points.
  3. Cut the built-in antenna like shown by the ORANGE lines

The antenna is a 868Mhz One , frequency used in France, where I live, for z-wave products.


This Does not work …. Did I do something wrong ?

Re: external antenna

Posted: 22 Jan 2019 09:11
by Arek
in manual there is only about breaking pcb antenna, but on internet You can find something about unsoldering resistor somewhere else about inductor so it is not clear.

Re: external antenna

Posted: 22 Jan 2019 15:31
by moidabord
I think I crawled every single page indexed by google about that subject... and still cant't find any answer to that question...

I thought this forum was the best place to ask my question, but maybe not..... is there a more appropriate place??

Re: external antenna

Posted: 25 Jan 2019 19:03
by Arek
Any help, advise?

Re: external antenna

Posted: 27 Jan 2019 22:51
by Arek
sorry for the size of the image but it must be readable...
so I had "few" free minutes (with 6month daughter it is not so easy ;)) I found my old ERSA soldering station and I did solder the u.fl socket and also You need to un-solder 0ohm resistor R3 and solder to R4 pads (or just make a tin jumper) (it cut off pcb antenna)
if You did break PCB antenna You only need to do R4 jumper

Better timing, more device in the range, RRSI -94 to -91 dBm

BUT sometimes on channel it is showing 0?! only in noise meter mode - on background history didn't record it (maybe some suggestions from PoltoS?)


Re: external antenna

Posted: 28 Jan 2019 14:09
by pierre2302
What is this razberry card?

Is this an official version?

What is the difference with this one?

Re: external antenna

Posted: 28 Jan 2019 19:08
by Arek
This a Razberry2 EU board. Official version of what? modification - no (I'm waiting for official manual), board - it is official version.
I don't know what is technical different between this two boards...but on the first look I would say - colour ;)

Re: external antenna

Posted: 28 Jan 2019 23:20
by moidabord
Thanks Arek for the help.

Unfortulatly, It does not give any result.
I unsoldered the R3 and made a bridge with the R4 , but there is simply no change...

the only device detected is the one placed just side by side with the controller...

Not far from giving up.... :(

Re: external antenna

Posted: 29 Jan 2019 20:35
by Arek

Re: external antenna

Posted: 30 Jan 2019 17:14
by ronie
Hi @ all,

please see the attached image and the instruction further below:
raz2_neu_antenna.png (988.9 KiB) Viewed 712 times
The 0 Ohm resistor is by default soldered on the red PCB antenna contact points. To use Wired Antenna or U.Fl Connector it is necessary to place the resistor on the green contact points.

> Unsolder 0 Ohm resistor from red marked position and solder it on the green marked position.

Wire length for 868 MHz:
λ =34,54 cm
λ/2 = 17,27 cm
λ/4 = 8,63 cm
(length shouldn’t influence the transmission quality, but it’s worth to test which length will give the best solution – start with the longest and reduce the length step by step until you are satisfied with the solution)