Amateur Radio FAQ

[gamer_jim]

I ordered one of those inexpensive USB-SDR modules and was playing around they Airspy last evening. I’m still scratching the surface and trying to learn about Ham radio, but I’m fascinated with how much technology is packed into this software/hardware combo.

I do have a question about Airspy. Do any users know how if it has the capability to work as a scanner? If so how? It seems like it has a built in record function, so it got me thinking that it would be useful if there were a way to scan and auto record any signals, then I could go back afterwards and discover where traffic is occurring.

I have an airspy mini. I wouldn't call it inexpensive at $100. They make better and more expensive ones. You can buy a cheaper SDR for $30-ish.

Yes you can set up the Airspy as a scanner using the SDR Sharp software. I haven't seen it but have watched videos of it being done. You have to manipulate the squelch and there are tons of plug-ins for SDR to make that easy.

 

[ToolAA]

I have an airspy mini. I wouldn't call it inexpensive at $100. They make better and more expensive ones. You can buy a cheaper SDR for $30-ish.



Yes you can set up the Airspy as a scanner using the SDR Sharp software. I haven't seen it but have watched videos of it being done. You have to manipulate the squelch and there are tons of plug-ins for SDR to make that easy.

Jim. I didnt buy the Airspy, I did get the cheap $30 device. I guess I was confused because the software that I downloaded was Airspy software. I’ll look for some plugins and see if I can figure it out.

 

[gamer_jim]

Jim. I didnt buy the Airspy, I did get the cheap $30 device. I guess I was confused because the software that I downloaded was Airspy software. I’ll look for some plugins and see if I can figure it out.

I understand. I have a buddy who has the less expensive RTL-SDR and he does some neat things with it. He can do ADS-B (tracking aircraft), broadcast FM and with the right antenna get decent HAM band coverage.

SDR # has a steep learning curve. I struggled with it too. I can now at least get around and listen to stuff. I don't understand all the filters. Usually when I find an interesting signal I just start messing with the filters until it comes in clearer. There's a couple good tutorials on youtube for SDR#. I never found one that explains all the filters but they do a good job describing the basic interface and how to move around.

I have a Ed Fong antenna on my roof which was made for 2M/440cm but I get all kinds of signals on that thing using my Airspy mini. I've faintly heard shortwave, loudly heard CB radio, 6M on up through 800 Mhz. The Airspy mini goes to 1.8Ghz, I think, but I've never heard anything up there worth listening to.

I found this website, Signal Identification Group. These guys have a good database and instructions on how to identify signals. They also have a discord server where you can chat with them. One night I found a digital signal on 6M and I asked them how to ID it. They walked me through how to record in SDR# and then post it in the Discord chat. They proceeded to analyze it and even though they couldn't ID it was interesting to read the discussion.

Good luck and let me know if there's anything I can help with. I'm no expert but can at least get around SDR# a bit.

 

[ToolAA]

I understand. I have a buddy who has the less expensive RTL-SDR and he does some neat things with it. He can do ADS-B (tracking aircraft), broadcast FM and with the right antenna get decent HAM band coverage.



SDR # has a steep learning curve. I struggled with it too. I can now at least get around and listen to stuff. I don't understand all the filters. Usually when I find an interesting signal I just start messing with the filters until it comes in clearer. There's a couple good tutorials on youtube for SDR#. I never found one that explains all the filters but they do a good job describing the basic interface and how to move around.



I have a Ed Fong antenna on my roof which was made for 2M/440cm but I get all kinds of signals on that thing using my Airspy mini. I've faintly heard shortwave, loudly heard CB radio, 6M on up through 800 Mhz. The Airspy mini goes to 1.8Ghz, I think, but I've never heard anything up there worth listening to.



I found this website, Signal Identification Group. These guys have a good database and instructions on how to identify signals. They also have a discord server where you can chat with them. One night I found a digital signal on 6M and I asked them how to ID it. They walked me through how to record in SDR# and then post it in the Discord chat. They proceeded to analyze it and even though they couldn't ID it was interesting to read the discussion.



Good luck and let me know if there's anything I can help with. I'm no expert but can at least get around SDR# a bit.

Thanks for the info. I built a quick j-pole last night and I found some sort of tv-like broadcast, in english that, I didn’t recognize. I listened for 20min and didn’t hear any commercials or station ID.

I would like to capture commercial aviation traffic. There is a BWI approach at about 10,000 ft right over my home.

 

[gamer_jim]

I would like to capture commercial aviation traffic. There is a BWI approach at about 10,000 ft right over my home.

Air Traffic Control or ADB-S?

 

[ToolAA]

Air Traffic Control or ADB-S?

I would like to listen to Air Traffic Control coms but ADB-S logging would be cool too. Maybe later after I get my feet wet.

 

[gamer_jim]

I would like to listen to Air Traffic Control coms but ADB-S logging would be cool too. Maybe later after I get my feet wet.

Both should be easy if you are that close.

If you are using SDR # they have an option for the band names over the frequencies. Should be about 118Mhz through 187.

For ADB-S I used this tutorial:
https://www.jeffreykopcak.com/2014/...h-rtl-sdr-adsbsharp-and-virtual-radar-server/

Don't worry so much about the antenna. My antenna isn't tuned for that band and I'm receiving data from planes 50+ miles away.

 

[Engine4]

Been doing a lot of listening on HF to see from how far away my antenna will receive. Lots of spanish, guess I'll have to learn that now!

 

[ToolAA]

I played around with my j-pole that I threw together using 1/2” copper pipe. I switched back to a 24” ground plane antenna to compare and it looks like my 64” pole is working pretty good. I did find some air traffic last night but there was a lot of hiss and very hard for me to make out much from the conversation. I did have very clear signals from Baltimore city PD which is probably 15mi from my house.

 

[gamer_jim]

Spent the afternoon with my friend trying to learn digital modes.

 

[ToolAA]

Spent the afternoon with my friend trying to learn digital modes.

Is the emphasis on “Trying”?

I see this was at least a 9 beer attempt.

Also when you say digital modes, do you mean Trunk/DMR communications?




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[gamer_jim]

Is the emphasis on “Trying”?

I see this was at least a 9 beer attempt.

Also when you say digital modes, do you mean Trunk/DMR communications?




Sent from my iPad using Tapatalk

9 would be on the low side.

For modes we are fairly confident with psk, but also tried mt63 between our laptops using baofengs in the same room.

We are still trying to figure this out but learning each time. Today we learned about volume levels and how to set the right tone in fldigi.

Or goal is to be able to communicate digitally across the 14 or so miles between our houses. I'm not sure if that is possible with 2M.


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[Traveler]

9 would be on the low side.

For modes we are fairly confident with psk, but also tried mt63 between our laptops using baofengs in the same room.

We are still trying to figure this out but learning each time. Today we learned about volume levels and how to set the right tone in fldigi.

Or goal is to be able to communicate digitally across the 14 or so miles between our houses. I'm not sure if that is possible with 2M.


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As long as your antennas are high enough that would be easy. Maybe a little harder if you are using 5W HTs, or the antennas are low with no directional gain.

 

[K31]

As long as your antennas are high enough that would be easy. Maybe a little harder if you are using 5W HTs, or the antennas are low with no directional gain.

...and there's no intervening terrain, or buildings.

 

[Engine4]

So I got a QSL card in the mail last week. It's from a guy in NJ saying I contacted him on 80M @ 0323hrs, using my original callsign (before I changed it to a vanity). I didn't do it, so is this mistake normal or was it someone using my sign?

 

[K31]

So I got a QSL card in the mail last week. It's from a guy in NJ saying I contacted him on 80M @ 0323hrs, using my original callsign (before I changed it to a vanity). I didn't do it, so is this mistake normal or was it someone using my sign?

How long ago did you give up your callsign and has it been reassigned?

Did he say he had a QSO with you or merely heard you? I've had SWLers ask me for QSL cards before. Strictly legitimate.

Last, he could have misheard someone's call who was like yours. He may even have your correct other info because he looked you up.

 

[Engine4]

Got the vanity 3/13, too soon to be reassigned. Said he spoke to me 0323, so I know for sure it wasn't me. Guess I'll chalk it up to a misunderstood call sign.

 

[Kagetsu]

9 would be on the low side.

For modes we are fairly confident with psk, but also tried mt63 between our laptops using baofengs in the same room.

We are still trying to figure this out but learning each time. Today we learned about volume levels and how to set the right tone in fldigi.

Or goal is to be able to communicate digitally across the 14 or so miles between our houses. I'm not sure if that is possible with 2M.


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Back when I was in the club. One guy was into packet. I remember they had digipeater for 2M. If I remember all right. It was long ago.

 

[Boxcab]

Sorry for the late reply here, been on the wrong coast for awhile...

A repeater that's mounted on a good sized tower or building ought to be able to hear you fine with 4W from 5mi or so away. I can routinely hit a repeater in AACO from PGCO a distance of about 20mi from the ground. I've even talked tens of miles through a AACO repeater from inside a car with no external antenna. But lot depends on where you are inside/outside, have intervening buildings or terrain between you and the repeater. Also, if you have a weak or low voltage battery, that can lower your output power. I've heard of this happening even with OEM battery packs that use disposable alkaline batteries versus the OEM rechargable NiCads or LIons. A small difference in voltage causes more significant drop in power.

To give another example": I live in Elkridge and can hit the Davidsonville repeaters (AACO) , both 2m and 70cm, from inside my house with 1/2 watt on my HT.

I'm near the Millersville Landfill and can not seem to be heard on W3VPR repeater. I can receive fine. Maybe we can setup a test some time.

Another consideration is that, at least with the other repeaters, if the tone is not correct, you'll hear the repeater but won't get in. If you're using my input file, I can't vouch it is 100% accurate for all repeaters because I added some of them from sources like TMARC but I haven't personally tested each one (since they are all over the state). Also, there are many repeaters that have the same input frequency/output frequency pair but different tones (they try to physically separate these) so you may hear one on a memory for a local repeater when it is actually another distant repeater.

When I have time I'll double check the file, its been awhile.

 

[K31]

I'm near the Millersville Landfill and can not seem to be heard on W3VPR repeater. I can receive fine. Maybe we can setup a test some time.

If you haven't you may want to try the W3VPR North County Repeater 147.075 PL 107.2 located near Curtis Bay.

The Mobileers also have repeaters in Millersville 146.805 and 449.125 PL 107.2

There are also repeaters in Jessup, Columbia and Ashton that have good coverage.