Direct fit RTL-SDR antenna ?

[alan_d]

Can anyone suggest a RTL-SDR antenna that would mount directly onto to the USB dongle?
Or an alternative dongle with an antenna directly mounted?
The existing mag-mount on cable is rubbish.

Or a case and suitable dongle that allow a threaded connector mounted on the case instead?

Thanks in advance.

[Paul_Sengupta]

The big problem with mounting the antenna to the dongle is that the MCX connector allows the antenna to rotate, so you need to also have some sort of mechanical restraint to hold it in place (blutac or something!). You can buy MCX to SMA converters, then use an antenna with an SMA connector (I use a small "chilli" antenna, it's good enough for ADS-B from transponders).

You can get dongles with SMA connectors on, but they're larger than the mini one supplied.

I've found the two MCX to SMA connectors I have are quite loose, though I haven't got one of the 90 degree ones.

Converters:

https://www.ebay.co.uk/itm/SMA-Female-Jack-To-MCX-Male-Plug-RF-Connector-Cord-Adapter-Straight-Gold-Plating/322923073860

https://www.ebay.co.uk/itm/1pce-Adapter-Connector-SMA-female-jack-to-MCX-male-plug-90-for-Antenna-Router/222098410756

These are the NESDR dongles with SMA connectors:

https://www.ebay.co.uk/itm/NESDR-SMArt-SDR-Premium-RTL-SDR-USB-Stick-w-0-5PPM-TCXO-SMA-R820T2-RTL2832U/152704226308

This sort of dongle comes with the adaptor, but apparently these Nano 3s in their metal heatsink cases transmit a fair amount of heat back to the Pi.

https://www.amazon.co.uk/NooElec-NESDR-Nano-Enclosure-R820T2-Based/dp/B073JZ8CC2

Antennas:

The only "native" directly attached MCX antenna I've found is the telescopic sort, like the one included in this bundle:

https://www.amazon.co.uk/NooElec-NESDR-Nano-OTG-Bundle/dp/B0747LVW59

SMA antennas - the larger they are the more you'll pick up, but even the small ones have a 40 mile range for transponders.

https://www.ebay.co.uk/itm/900-1800MHZ-SMA-male-plug-GSM-GPRS-Antenna-for-Wireless-Data-Transfer-5CM-Chili/222099445289
https://www.ebay.co.uk/itm/900-1800MHZ-SMA-male-90-GSM-GPRS-Antenna-for-Wireless-Data-Transfer-5CM-Chili/222099444914
https://www.ebay.co.uk/itm/900-1800MHZ-SMA-male-90-GSM-GPRS-Antenna-for-Wireless-Data-Transfer-10CM/222099444734
https://www.ebay.co.uk/itm/900-1800MHZ-SMA-male-Built-in-GSM-GPRS-Antenna-for-Wireless-Data-Transfer-10CM/222099445033
https://www.ebay.co.uk/itm/900-1800MHZ-SMA-male-plug-GSM-GPRS-Tilt-Swivel-Antenna-for-Ham-radio-11cm/222099445367
https://www.ebay.co.uk/itm/GSM-900MHZ-Omnidirectional-Wireless-Module-Antenna-SMA-Head-5DBI-well-best/231429960178

Note these are examples and not recommendations.

Or check this list out for proper 1090MHz antennas:

https://www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&_nkw=1090+antenna&_sop=12

[alan_d]

Paul,

Wow, thanks for all the links, i'll look through them later.
I saw that someone had 3D printed a case a while ago to incorporate everything, that's another option with the right antennas as I have a 3D printer. Happy to print cases for others if a suitable design already exists ?
I'd like to get to the point of a 'one box' solution (maybe with power-bank incorporated) rather than the mass of cables and stuff now.

Alan.

[Paul_Sengupta]

Some people are building their units into Stratux cases as available on Amazon.

https://www.amazon.co.uk/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=stratux+case&rh=i%3Aaps%2Ck%3Astratux+case

[alan_d]

They look interesting, might be a good option.
I assume that I could use the 1090MHz antenna supplied with that case into the dongle, and the other antenna mounted to the bridge with a suitable cut-out.
Do we know if GPS would go through the plastic case OK ?
Could add a DC socket into the case instead of relying on the delicate micro-USB socket on the Pi...

[Paul_Sengupta]

Yes, the GPS is normally ok, but the Stratux case has a small hole through which you can route the wire of the GPS Mouse if you need an external GPS.

[Ancien]

You really don't need a special antenna.
Just remove 69mm of the coax sheathing from the end of whatever length of extension cable that you need [as short or long as you like] from your adsb dongle and cover this bit with heat shrink. Thread through a suitable plastic sucker and stick to side window or screen. See photo.
It's as minimalist as you can get and dirt cheap. IT WORKS. Excellent range. Nothing to break and very easily carried when changing planes.
Why does everybody want to spend so much on unneccessary add-ons?