USB Cable vs LMR 240 - Canada

FlightAware ADS-B Flight Tracking
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Fairly new to the Feeding community and currently just have my Antenna propped in the window but want something better and hidden from my Fiance. Unfortunately my HOA restricts me from having my antenna on the roof so will be doing the next best thing in having it in the attic - shingled roof.

My first thought was to have a plug put in the attic so I could put my PI + Antenna there but being in Canada I worry it would get too cold in the Canadian Winters, also the temperature extremes an attic endures in the summer it just doesn’t seem wise. I’d also like to access my PI easily.

This leads me to my next question, keeping my PI in a temperature-controlled room should I use a USB extension cable to have my USB dongle in the attic with a short LMR cable or should I keep my PI + Dongle together but have a longer LMR 240 Cable. Thinking 15ft (4.72m) cable whether it be USB or LMR 240. USB extension is by far the cheapest option but is it good enough. Thoughts?

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I strongly suggest you keep your Pi and dongle together in the temperature-controlled room and run that relatively short 15ft LMR length of cable to the attic antenna. You would benefit some by using a KMR400 coax cable.
eg.
![XRDS -RF KMR400 SMA to N Cable available in different lengths on Amazon.
I run my Pi4 and FA blue dongle in the house and run a 50ft length of that same cable up to a 49 foot high Vinnant antenna on a mast mounted to the eve of the single-story roof. I do not have signal issues with the 50ft length of that particular coax cable. Easy access to the Pi and dongle is a wonderful thing and the electronics benefits from the AC cooling.

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AC cooling ? Heck we can suffice with just opening the windows over here :zany_face: the few hot days in summer we have here are easy to cope with :smiling_face_with_sunglasses:
The heater has a bigger job to do in this climate :wink:

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Yes, I remember living in upstate New York near to the great lakes for much of my life. That was at a latitude very similar to your’sTom. Not much of a summer and for the most part, no AC in the houses or cars. Sure is different here in central florida.

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If the Pi need to be out of sight (ie. in the attic), PoE is worth concidering.

Some people report success with USB extension leads, but others see a serious drop in performance.

Extream cold shouldn’t bother a Pi so long as you are not getting any condensation - the Pi should be warm enough so that’s not a big risk.

As above, a short run of coax is probably the easiest to install.

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Thanks for everyone’s answers thus far. Really is a learning curve!

PI doesn’t necessarily have to be out of sight but cables in windows is a no go anymore - we have cats too that like to play.

I’ve decided to go with the Coax into the wall and then up into the attic. I currently run a 1m LMR 240 to my antenna that currently sits in the window and already find it very rigid, can only imagine a 400. Not really sure how I’d get a 400 cable out of the wall without introducing a 90d connector & 2nd cable and thus probably introducing more loss or is it rather negligible?

After a little more research, my thoughts are as follows. Use a LMR 240 or even thinner cable (any negative effects?) but introduce a Uputronics LNA at the Antenna and Bias T injector after the USB dongle. LNA supposedly has 27db gain so would negate any loss the cable (thinking maybe 25ft now to allow options) has - hopefully I understand this correctly!?

Having to have my Antenna in the Attic as opposed to outside, I really don’t want to lose any db even the minimal with a 400 Cable, but is there still a need for it (thick cable) if using a LNA?

A thinner cable would introduce more loss but is that something I may actually want so that the LNA doesn’t overpower the FA Pro Stick Plus which already has an LNA though built into the dongle and thus at the wrong end of the cable. I suppose I’ll have to turn the gain on the FA Stick down too if using an external LNA or would Auto Gain sort that?

I do live on the edge of a city (Calgary) with Cell towers etc around so don’t want to introduce unwanted noise but honestly don’t understand it all that well. Open to any and all suggestions. TIA

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The KMR400 coax is pretty flexible for a thicker quality shielded cable. You can pretty easily have a fairly short radius turn in the cable. You certainly don’t want to introduce any 90-degree coax connection in the line. I used to work in the cable industry and detailed testing showed that they induce serious losses and signal noise from reflections. I find that using top quality coax right from the start saves a lot of money and effort in trying to filter and amplify poor signal quality/noise and strength resulting from the inferior coax.

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(Edit: Read you next post, and saw that you are in Calgary.)

Where are you in Canada? I’m in Ottawa.

My entire setup is hanging off the unheated garage rafters. FlightAware antenna, RTL-SDR Blog Triple-filtered LNA and a FlightAware Blue stick. No more than 0.5m of cabling total.

No problem in either winter or summer. The temperature in the summer used to be borderline when I used an RPi 3B+. That has eased up after switching to an RPi 2 Zero W.

Accessing the RPi is via Wi-Fi. Very reliable.