Newbie Equipment Questions

[impala454]

I've been dabbling with SDR for a couple of years on and off and now want to build out a nice system for my home. First a bit of background, I've been a software developer by day for the past 17 years and linux/windows software development/configuration is no problem for me at all. I dabble in electronics both at work and in a hobby basis and can do simple soldering. I've built stuff like an anemometer so I'm handy enough to run cable and build things that need building. I'm in the Houston, TX area pretty close to Ellington Field, so I feel like there's a wealth of interesting stuff to listen to. All that said, I'm a bit overwhelmed with the fire hose of information available out there for SDRs and have a few goals:

1. Set up a permanent ADSB listener which I can then use to help identify planes near my house, and possibly feed data somewhere online.
2. Set up a permanent scanner/listener for local police/fire, and various stuff like FRS/aircraft/etc.
3. Set up a permanent ham setup for participating in my local club (later/longer term goal)
4. Set up a non-permanent dongle I can just fire up SDR# and play with. Not permanent, but "plug in dongle, plug in antenna, and good to go" kinda thing.

Questions I have related to above goals:

1. Antenna(s) - I'd like to choose and purchase an antenna(s) that I can put in my attic. I have a pretty big space available and don't have radiant barrier or anything. What I don't understand completely is, if I get something like a large discone antenna, can I "re-use" that antenna for all of the above (or at least ones where the frequencies make sense)? I've looked on amazon, is there any specific one that's a good "one size fits all" for newbies?
2. Cabling/wiring/splitting - Once I get an antenna set up, I'd like to run the cable down through an existing spot where I ran network cabling, which runs down a wall right to the back of my computer. I'd like to run the cable down to that area and put a nice jack on the wall. Is there issue with this? Do extra junctions create problematic noise? Is there issue with me splitting that line to go to multiple SDRs? If no, is it better to split "early" near the antenna and run more cables, or right by the SDR itself?
3. Other pieces - I see folks using things like ham it up, amplifiers, or other in line filters in their setups. What particular items match up with the goals above? Also is there recommendations on specific ones, and their mounting location? I.e. if I get XYZ amplifier, should it be mounted in the attic near the antenna or is it ok for it to be near the computer at my desk?

Current equipment I have:

• Nooelec NESDR Smart
• Nooelec NESDR mini 2 + the small telescoping antenna it comes with
• Cheap 978MHz and 1080MHz antenna with SMA connectors
• Terk HDTVA with standard RG6 run down to the same closet
• Baofeng UV-5R
• A giant spool of RG6 (like 700 ft) available for any use (could I build antennas with it?)
• Plenty of Raspberry Pis (3/4), arduinos, computers

 

[merlin]

Well, This is awful complicated, My suggestions for permanent setups.
#1> Set up a dedicated SDR and software for ADSB with tp/ip for something like broadcastify.
#2> Get a decent scanner, A scanning SDR setup can get complicated and you would need yet another SDR.
#3> Another SDR(?) something like winradio can do that. #4 below if you just want RX/logging and such.
#4> Your SmarT will do fine, all of the above included with added software and some hardware.
Now for the simpler stuff.
>Antennas and cableing.
A typical dicone is not very big and kept above/away from electrical wiring should do for 50 Mhz through 1300 Mhz.
There are the larger for like 20 meter ham, but a smaller amplified loop in the attic works well below 50 Mhz.
Switching is better than splitting, less loss, but you need a tap for each setup.
I do recommend a good low noise preamp and may need broadcast traps and bandpass filters.
RG6 cable is 75 ohm, for your short runs the mismatch is largely insignificant. RG-58 would be better.
Used for an antenna itself, the RG6 is as good as any.
You can toss those Chinese whips that come come with these cheap SDRs they are not as good as TV rabbit ears.
>OTHER Pieces:
AMPS/TRAPS/FILTERS do better at the antenna, something like 'ham-it-up' you use at the SDR to convert radio below 50 Mhz to VHF that the dongles work best at.(consider, these dongles are designed after TV tuners.)
My best suggestions to get you started and you will have a LOT more questions as you get progress with this.
73s

 

[impala454]

Great, thanks for these answers! Quick follow up:

- You mention RG6 isn't too bad for short runs, how short? I'd guess my run from the antenna in the attic to the SDR near the computer would be about 40-50 ft tops.

 

[Delta2_Coms]

I would consider 40-50ft a short run. RG-6 is a pretty low loss cable and will handle that great.

Just be cautious with RG-6 when you get to the ham radio stuff. Most ham equipment (and other radio equipment) is designed to be used with 50 ohm cable. RG-6 is 75 ohm, which for your receive only applications will be just fine. But when it comes time to transmit on the ham equipment I'd recommend using a 50 ohm cable like RG-8/U or RG-213.

-All the best