Mystery component on Yun board?

I have managed to successfully attach an external antenna to the Yun, but it is a hack.

I had misread this thread, bought a “SMA Female Plug to IPX U.FL Female Pigtail Cable” ( http://www.ebay.co.uk/itm/231098912466) , connected it to the Yun and saw no improvement.

Under a microscope, I could see that both the socket and plug were female. (see attached photos).

As I had nothing to lose, I thought I would have a go at creating a pin that would bridge the two female connectors. 1/0.6mm solid core wire fitted snugly in both connectors. I guessed at the correct length. Luckily i seemed to judge it about right and the plug is held firmly on the socket.

Amazingly, it worked. The Yun seems to auto sense the stronger signal. With no antenna connected to the SMA connector, the signal strength was about 35%. With the antenna connected, it bumped up to about 80%. I plugged/unplugged it a handful of times to convince myself it was working.

Obviously, with no soldering, this is might not be the most reliable of connections.

I would be interested to know from an RF expert whether I have managed to fluke a solution or whether the RF signal can jump the gap of a “not great” connection.

Let me know if you can reproduce my results.

Pete.

Custom made connector:

original murata connector, price not working( $80) and height is not. I got customer engineer drawing done. but MOQ is too high. plus Intellectual property?

Case to hold custom made connector.

sonnyyu:
Custom made connector:

Wow. Interesting solution, but it costs more than the Yun! No wonder you didn’t go into production.

It’s a bit of a hack, but I think Pete’s solution is much more practical.

pete_dl:
I would be interested to know from an RF expert whether I have managed to fluke a solution or whether the RF signal can jump the gap of a “not great” connection.

I’m not an RF engineer (as far as I’m concerned, RF is black magic!) but while I’m sure that the “not great gap” is introducing some reflections that may affect signal quality, it’s hard to argue with the success you’re reporting.

Does anybody know if there’s a way for the Yun to report signal quality (or signal/noise ratio) in addition to signal strength?

ShapeShifter:
Wow. Interesting solution, but it costs more than the Yun! No wonder you didn’t go into production.

80 is murata price, I got quota about few for 10K MOQ. I don’t need 10K for my single Yun. :money_mouth_face: Plus It might be murata Intellectual property?

ShapeShifter: ... Does anybody know if there's a way for the Yun to report signal quality (or signal/noise ratio) in addition to signal strength?

 iw dev wlan0 survey dump
Survey data from wlan0
        frequency:                      2412 MHz
        noise:                          -95 dBm
        channel active time:            105 ms
        channel busy time:              36 ms
        channel receive time:           35 ms
        channel transmit time:          0 ms
...

sonnyyu:         noise:                          -95 dBm

Thanks! This would be the interesting number to see with Pete's "imaginative" adapter. But of course, to really know if it's significant, it would need to be compared to the noise figure for a a "proper" adapter...

Still, it would be interesting to see Pete's noise figure with and without the external antenna.

|500x241

They are completely incompatible with the U.FL type.... No amount of forcing, twisting or whining is going to get these to mate.

http://forum.arduino.cc/index.php?topic=188976.msg1574902#msg1574902

The top connector inside have to build in with forcing to connect well & cut off build in antenna.

I have replaced the original outlet with one that will mate with any ordinary antenna lead. I have mounted my Yun + sensor shield in an old wireless router case, using the antenna giving me good house wide connection I am not an R.F. engineer but can solder with a magnifying loupe to my eye, requires a steady hand

|500x274

Those connector works fine with following limitations:

  • void warranty
  • require handyperson
  • lost auto switch between int/ext antenna

awardblvr: Here's an article on how these work:

http://www.murata.com/articles/ta0791.pdf

These are for test...Not intended to be used as a permanent connector for range extension. You may get lucky. It is rated at 100 cycles max. (Remember they probably used a number of these cycles during manufacturing.)

What does "rated at 100 cycles max" mean?

thataintworking: What does "rated at 100 cycles max" mean?

In this case, a cycle is a single instance of mating and disconnecting the connector. This connector is rated for 100 such cycles, after which the manufacturer does not claim that it will still make connections properly. In other words, it is a low duty cycle connector that is not designed for frequent connections/disconnections. If you are going to use it, plan on leaving the antenna connected and don't mess with it a lot.

It seems the 100 cycles refers to how many times you can physically plug and unplug this connector…if you get the adapter cable you will see that it snaps on with gentle pressure…so my guess is that if you continued to physically plug and unplug this connection…more than 100 times…eventually it would wear out. But as for function, it works well for me, and gave me significant signal boost- wifi signal from 150" away.

here are the parts I used:

http://www.digikey.com/product-detail/en/132171RP/ACX1247-ND/1011924

http://www.digikey.com/product-search/en?site=us;lang=en;vendor=490;Keywords=MXHS83QE3000

acastronovo: It seems the 100 cycles refers to how many times you can physically plug and unplug this connector...if you get the adapter cable you will see that it snaps on with gentle pressure...so my guess is that if you continued to physically plug and unplug this connection...more than 100 times...eventually it would wear out. ...

You guess is correct. the other side adapter cable will last thousands times more than this connector.

This connector is design for RF calibration purpose only, more less few times use, but adapter cable is design for RF calibration thousands RF circuit boards.

pete_dl: I have managed to successfully attach an external antenna to the Yun, but it is a hack.

I had misread this thread, bought a "SMA Female Plug to IPX U.FL Female Pigtail Cable" ( http://www.ebay.co.uk/itm/231098912466) , connected it to the Yun and saw no improvement.

Under a microscope, I could see that both the socket and plug were female. (see attached photos).

As I had nothing to lose, I thought I would have a go at creating a pin that would bridge the two female connectors. 1/0.6mm solid core wire fitted snugly in both connectors. I guessed at the correct length. Luckily i seemed to judge it about right and the plug is held firmly on the socket.

Amazingly, it worked. The Yun seems to auto sense the stronger signal. With no antenna connected to the SMA connector, the signal strength was about 35%. With the antenna connected, it bumped up to about 80%. I plugged/unplugged it a handful of times to convince myself it was working.

Obviously, with no soldering, this is might not be the most reliable of connections.

I would be interested to know from an RF expert whether I have managed to fluke a solution or whether the RF signal can jump the gap of a "not great" connection.

Let me know if you can reproduce my results.

Pete.

I know microwave Pete. There is no 'jumping a gap' with microwave. You'd need a plasma for that. In fact as frequencies get higher and higher signal begins to travel only on the outside surface of the conductor to a greater and greater degree.

You've succeeded with your novel pin and I'm about to do the same thing, because my fingers are literally 50x the size of these connectors, otherwise I'd solder in a U.Fl male. I have access to a PCB microscope at the NW Maker Lab, but my fingers are too big (since I'm old) and I'm not so steady anymore.

One thing to be aware of is, assuming you'd used copper wire, it will oxidize; this means the outer surface. Notice all other components are gold-plated. You have to make this connection gas-tight to prevent this. I'll use silicone grease ("dielectric grease", auto parts store) to fill my connection. I always inject it into RJ45's when I'm making up cables, whether they'll go outdoors or not. I'll do my best to file the ends of the pin flat.

Then I'll hot-glue the wire to the board to reduce strain on the connectors, since this is going in my Tesla. I've rooted it and the Yun will give me remote access to the (hacked) car.