Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

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Which qualities/features does an SDR radio device need to be usable for Amateur Radio?

I know what things to note when selecting an analog amateur radio, but SDR devices have completely different specs, e.g. sample rate and resolution. What do I need to know about the device to make sure it is suitable for working Amateur Radio…
jkj
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Phasing harness for antenna array

I understand that certain antenna designs (particularly phased arrays) require feeding each radiating element with a certain number of degrees of phase separation in order to achieve a desired radiation pattern or beamwidth. I found this 2-meter…
Craig
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Getting Started with Digital Modes on VHF on Linux

I am interested in learning about digital modes using 2m and Linux. I have a couple of older 2m rigs (HTX-212 and an old Yaesu) with no additional hardware, like a TNC. What current resources exist for hardware setup and software configuration for…
Rob Gibson
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Remote SDR on the internet other than WebSDR?

Besides WebSDR, what remote Software-Defined-Radio stations (for shortwave or amateur bands) might be available for open public access over the internet? What protocols do these SDR stations use to stream data over the internet? Do any of these…
hotpaw2
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Why are commercial SDRs so limited in operating frequency?

I spent a bit of time researching SDRs, mostly looking into the possibility of building an all-FPGA-based TRX. There are a lot of commercial ready solutions; some are cheap, some not, but they all tend to be operating from 50/70 MHz frequency…
Ulterior
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Is calling the Palmer Station (Antarctica) via IRLP without prior arrangements acceptable practice?

Until I can get an HF rig, I've been using my HT through a local repeater IRLP node. I've successfully made a few contacts doing that, but I recently noticed that Palmer Station in Antartica has an IRLP Node (#8838) listed. I tried making a contact,…
penguin359
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Would it be possible for a software-defined FM receiver to demodulate two signals on the same frequency?

When two FM signals are transmitted on the same (or about the same) center frequency, either you hear only one or you hear that noise I'm sure most of you have heard. Would it be possible for a software-defined receiver to track both signals and…
Someone
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What is a fixed digital message forwarding system?

What is a fixed digital message forwarding system? I noticed this on the lower end of the 222MHz allocation in the US but it's not explained on the band chart:
Adam Davis
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What is the best time of day/Band to make a contact with Hawaii from the East Coast?

I need to get Hawaii for Worked All States, and live on the East Coast (Virginia). Furthermore, I have a poor antenna, and thus only the prime times of the day seem to really be opened for me. What time of day/band is the best to make the QSO?
PearsonArtPhoto
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How to Evaluate Antenna Data

I found some data on antennas that had been tested for a specific radio. I'm trying to decipher what this data means and how one would go about gathering it. Are there any good resource for learning how to read and understand this…
Dan
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What is the appropriate length of an antenna for a handheld on 2 meters?

I want to upgrade the stock antenna on my Baofeng uv-5r for which I mostly use the 2 meter band. The quarter wavelength for this band is about 19.2 inches, but when I look for antennas, they are typically 15.6 or 7.5, or some other seemingly random…
Ryan J.
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Am I really receiving FT8 signals from 12,000 km away on 144 MHz?

I have been using an Ettus B200 SDR to receive FT8 transmissions in the 2-meter band (144.174 MHz) using the WSJT-X software. Signals are received using a telescopic antenna inside on a window ledge with approximately 1 m of cable. I have made no…
David
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What kind of antenna has a spiral connected to a reflector like this picture?

The description on the antenna says it is used for satellite communication, but it was taken in 1984. Is this an antenna style that is still in use? What is it called? What kind of gain should be expected? Is this a style used primarily or only for…
Jason Petrilla
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Why is my diplexer such a spectacular failure?

I'm trying to create a diplexer for the 2m and 70cm bands so that two antennas can share a feedline to my "shack". My radio is a Yaesu FT60 handheld, 5W max. I have home made a j-pole for 2m, and a neat little ground plane antenna for 70cm, both of…
user14945
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How can I calibrate a SWR meter?

I would like to build my own HF (1.8 - 30 MHz) SWR meter, however I'm not sure how I can calibrate the meter without an accurate power source. I'm targeting a power capacity of 150 W so I can use it with my HF radio. However, my test equipment at…
W5VO
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