Any danger in using router antennas for NRF radio?

  • I took apart an old Linsys WRT45G 1.1 router I had laying around and decided to use that to enclose my gateway. It's big, but I like it for nostalgia purposes. The antennae on the back are much larger and connect to a much larger connector -- I'd like to use them because they fit in the holes that are already there. They are both 2.4GHz -- is there anything I should be aware of before I switch my little sma antenna out for this larger?

  • Hero Member

    @linus72982 did a similar thing works as good as a std. Nrf24l01 with antenna.

  • @linus72982 To be safe I would use the nRF24L01 PA LNA adapters as they already have an SMA connector and are designed to be used with an external antenna. I would then find some SMA to I am guessing TNC (which is what I am guessing the connector is on the router) pigtail adapters and you should be able to replace the existing connectors for the pigtails in a bulkhead fashion. Verify the type of connection that your antennas have and get a pigtail adapter to match whatyou have. Once you have that set up the SMA connectors should connect easily to the nRF radio and work rather well. They both run on 2.4GHz, so there should be no trouble.

    One thing to note about SMA connectors. They have two different styles of these connectors.

    The first one if you look at the outside threaded end, you will notice that there is a male center pin that protrudes from the connector. Looking at the other end with the hex head, the center is the hole that receives that pin.

    If you look at the second link on the outer threaded end, the center is the hole for the pin that is now on the hex head end.

    All of the nRF24L01 PA LNA modules that I have seen use the pigtail in the first link.

  • A quick related question:

    If I add the router antenna, I shouldn't get any increased range or anything unless I up the power, in which case I'll have to tweak the radio component to handle it, correct? So, now I'm wondering if this is even worth it other than for looks and how nicely it fits into the case. Also, if I wanted to use both of the router antennas, would I have to boost the power even further or just split it?

  • @linus72982 You will probably get slightly better range with one of the antennas. The original antennas that come with the modules are probably 1/2 wave antennas whereas the ones on the router could possibly be 5/8 or maybe even full wave which might give you a little gain. The receiving end of the module might not see much with the added length, but where you would get the boost is when it is transmitting. I am not sure that you would want to hook up both antennas as that may hurt your SWR on the transmitting end which would hinder performance rather than help.