Are There Any LNAs with N-Connectors Available?

If you are going to use an LNA, the chances are that you will want it near the antenna and use a coax cable made for outside use which generally means N-connectors, or at least not SMA connectors, yet all the LNAs that seem to be available only have SMA connections. Are there any available with N-Connectors?

 

Probably not at a reasonable price. What's the problem you are trying to solve?

 

- James
I was trying to keep the LNA as close to the antenna as possible while keeping the possible points where water could get inside connections to a minimum.

- wiedehopf
You are right, that is a steep price - too steep.

You are also probably right about going with the LMR 400 and seeing how it performs before trying to solve a problem that might not exist. The current installation is a home made quarter wave ground plane with the SDR and Pi mounted on the mast directly below the antenna in a weather proof box. It works but I would really like the Pi where it is more accessible. An improved antenna with the LMR 400 cable should be no worse, and in theory should even be slightly better, than what I now have. Time will tell.

Thanks to both of you.

 

I run 50' of LMR240 / KMR240 without issue. If you get closer to 75' then use LMR400 / KMR400. At 25' you can get away with LMR195 / KMR195 or equivalent.

https://globe.adsbexchange.com/?feed=BDapXDiLBDz7

People really get bad advice and overthink this.

I've seen people buy really terrible coax cable then put LNA on it or go through all kinds of complex idiocy because they got bad advice. They will argue that the coax is perfect, blah blah - I make no friends in this regard. Keep it simple. I can place a PCB antenna with 3dB of gain in my paper towel holder on my kitchen island and get 100 NM in a metro are with lot's of ambient RF.

If you amplify a signal, you are amplifying the noise also. Use good coax, use a good antenna that doesn't pick up out of band noise and you will get theoretical range for your location.

The one item that a some people need is a filter, but only if antenna is close to loud transmissions sources - like an FM radio station, cell tower, ham radio transmitter.

1090/978 barrel filter
https://www.amazon.com/ADS-B-Dual-1090-Band-Pass-Filter/dp/B010GBQXK8/

Put your latitude, longitude, and altitude in http://heywhatsthat.com/ - the Upintheair layer will give you an idea of what you should be getting theoretically. You can change the expected altitude son the bottom of the map.

ADS-B is line of sight. If you have obstructions, or antenna is in the attic, etc - you will never get close to theoretical even if you add the most expensive LNA. 1090Mhz also doesn't penetrate materials with high metallic content, like roofing.


FYI, these cables are fantastic. I've probably purchased 100+ of them in the last 2 years for various installs.

https://www.amazon.com/gp/product/B00QZEQ5EA/



I can't stress this enough, don't over think it.

There was this whole thing going around with people running 30 feet of USB cable that required power boosting to overcome the voltage drop so SDR would function properly because some uninformed loud mouth said you have to have the SDR 6" from the antenna. The real problem was this guy was using coax that was not intended for Ghz level frequencies.

 

Also, not to plug our stuff, but if you are US based - we took a lot of time to test and design our dual band antenna.

https://www.amazon.com/ADSBexchange-5-5dBi-N-Type-Female-Antenna/dp/B089Q4BVCB/

 

while its a bit wild, im working on using a high power Cisco WiFi AP Tube. ive broken the seals on the tube to get the electronics out, im looking to see if it has a bandpass filter on it for 2.4 and 5GHz, if it does, ill strip that out. i searched for weeks on end looking for a schematic of the damn thing......its a 2 foot Cisco AIR-ANT1728 AP WiFi access point PVC Tube

ill run the 1090/978 filter in its place, because i have not 1, but 2 Cell towers within a mile of me, one Verizon and one TMobile/ATT both on opposite sides of me about 3/4th a mile each direction, so im getting sandwiched by two towers. i have a small sealed box in the works and i'm going to mount the antenna itself at the highest point of my peaked roof which is just above surrounding treeline, so its basically open sky LOS. ill run the coax through a rubber grommet in the wall with a splash guard to keep it sealed from the outdoors to the Pi, and i already have the Pi4 mounted with ventilation in the attic and 1090dump loaded into it. that runs a Cat5e length down the entire wall which is the same exterior wall as my entertainment basement room where my PC Desk is with my switch and router. those are already jacked in and set for Static IP which is also running a DYNDNS account.


Sorry for the blurry picture on the length one, my cat is a complete butthead and jumped on my back when i took that shot, never thought to take it again. ill get a much cleaner one when i return home from the holiday,

 

here is where its going, most of the trees in the upper left corner are gone now, a new neighborhood was put in well after this Birds Eye image was taken. i blocked all the street names for security obviously and removed the Lat/Long