USB dongle Ant-In to female f-type?

Hi all,

Looking at my rig tonight (as part of rebuild), my antenna input goes out to a BNC pigtail (c3") then into a bnc to ftype pigtail, then into the main feed coax.

AFAIR, the ant-in on the dongle is SMA?

Is there a SMA (or what ever ant-in is) to female f-connector adaptor or straight through pigtail?

Thanks :slight_smile:

(BTW - without my amp, power supply, external antenna or filter - just running direct from self-build ant internally to the dongle. Picks up - frankly - booger all :wink: Little dissapointing really - was hoping it would pick something up with oout the amp (till I get me new bits).

Collectd shows no adsb signal range at all, and Message Rate and Aircraft seen max out at 0.8 / 0.8 on the charts…

Most dongles are MCX, but it can vary. You probably want a short pigtail rather than an adaptor, just to reduce the mechanical stress on the dongle connector.

I have some SMA and some MXC.
Neither are F-type(looks like SMA but is not).

What brand and model is it?

There are cheap and better, RG195, pigtails.

This is SMA
http://rtlsdrblog.rtlsdrblog.netdna-cdn.com/wp-content/uploads/2013/04/main_dongleonly_site2.jpg

These are MXC


Thanks @johnhawkes2030 - dongle definately has the MXC (push fit, def no thread like the SMA).

I’ll have a look around for MXC to male F-type.

Thinking pig tail from the dongle, straight into the power supply / injector for the amp?

@Obj - with my external ant out of the loop (pending rebuild), I’m using my original spider ant that I build from info on here.

USed to work really well using exactly this same rig (including my crappy BNC pig tail I hacked together!), but with amp and psu.

Collectd shows very little reception or anything, eith sporadic spikes between “none” and “a few” aircraft range plots…
I apreciate it’s difficult to comment till I post pics (this weekend), but the sporadic nature of the results is what I saw before I realised the coax was full of water.

I’m now of course on completely different coax - all the way from the (dry) antenna and the dongle.

Does this suggest an intermittant connection somewhere, or just poor range with out the amp?

The three questions I have for you are: **How long is your coax run, What kind of cable is it, and what are your gain settings?
**
If you turned the gain down on your dongle when you were using the pre-amp, you might need to turn it back up.

If your cable is something sub-par for this application like RG-58, and your cable run is 100’ - you’re going to lose almost all your signal before it gets to your dongle, and then lose even more with the impedance mismatch between your coax and adapters.

On that subject, your multiple adapters may be introducing multiple signal-robbing impedance changes, but I can’t say without knowing your setup.

Anyway, first I’d check the gain, then I’d see if the coax run is bad by temporarily plugging the antenna straight into your dongle (through your adapters, of course) eliminating the long cable run to see if that helps.

(my money is on gain)

Micro CoaXial

MCX :wink:

Thanks @JonHanford

Turned out to be a duff cable / bad crimping on my part… :wink:

The dialectic had pulled away from the pin in the BNC, hence wasnt giving continuity…

Re-did both ends, and back to normal now… :slight_smile:

flightaware.com/adsb/stats/user/cy80rg

(Preamp, filter and ant en route for upgrade… :slight_smile: ).