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Post by milspec on Oct 4, 2019 8:06:15 GMT 10
In my recent efforts to head down the HAM radio path I discovered Software Defined Radio (SDR) which has taken off recently in the comms world - and I can see why. For about $200 you get a wide band receiver that plugs into your PC and gives you some extraordinary receiving (No transmit) capabilities and a sophisticated user interface to find and listen to broadcasts (SW/MW/HAM/VHF/UHF). If you do have a HAM radio you can link it to the SDR via the PC. For example my HAM radio is a decent bit of gear but it doesn't have a spectrum analyser/Panoramic display, the SDR adds that capability to my HAM radio which can then transmit on those freqs if desired.
In a prepper sense, this kit allows you to monitor the HAM bands. You'll need simple wire antennas (to cover different bands) to pick up the signals.
Caveat, I'm not a stranger to comms but I am new to HAM/SDR, that said you don't have to be a genius to see the benefits of SDR.
I bought an RSP1A and it includes the SDR Uno software which does all the signal processing and display on the PC.
Here's a quick intro without too much geek speak (unlike most HAM radio videos!)
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Post by Joey on Oct 4, 2019 11:23:38 GMT 10
Nice. Will you need a fancy modern *fast* computer to run this program? I'm getting closer to having to fork out for a new computer for myself since mine doesn't allow me to use any video editing software for doing my business videos etc as it doesn't have the capability for a video card upgrade
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Post by milspec on Oct 4, 2019 12:41:51 GMT 10
I built my PC back in 2012, so its not new but I did build it as a video/photo processor at the time. Its working the SDR just fine. Progress report for my setup .... I'm still waiting for a proper HF antenna and some other gear to be shipped to me so in the interim I strung up a 20m length of speaker wire to a nearby tree, no baluns or anything like that and used the SDR to find a signal at 7MHz (suits a 20m wire antenna) which I could listen to on the SDR and I fine tuned it on the HAM radio. I also ran an earth wire from the antenna plug outer case to a copper earth rod outside - that makes a notable difference.
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Post by Joey on Oct 4, 2019 16:33:01 GMT 10
Nice setup. Been wanting to get into radio gear for many years now but never had the capital to get started. Always fancied the Yaesu 457D radio so I could take it mobile if needed.
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Post by milspec on Oct 5, 2019 7:50:48 GMT 10
Nice setup. Been wanting to get into radio gear for many years now but never had the capital to get started. Always fancied the Yaesu 457D radio so I could take it mobile if needed. I'm guessing you meant the 857D because it is compact. I initially considered that one too but in the end chose the 450D because it relies less on menu driven controls. It s probably 2x the size of the 857 but still luggable in a vehicle.
So last night was the first 'evening test' of the SDR and my el-cheapo 20m of speaker wire stuck in the antenna hole. I was super impressed to be listening to a group of Yanks having an extended chat with a group of Aussies plus another conversation in what sounded like Japanese. That was at 7MHz/40m wavelength where my 20m of speaker wire was acting as a 1/2 wavelength antenna. It performed better there than it did at 3.75MHz/80m(1/4 wavelength).
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kiwi
Junior Member
Posts: 45
Likes: 52
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Post by kiwi on Oct 18, 2019 20:58:50 GMT 10
In my recent efforts to head down the HAM radio path I discovered Software Defined Radio (SDR) which has taken off recently in the comms world - and I can see why. For about $200 you get a wide band receiver that plugs into your PC and gives you some extraordinary receiving (No transmit) capabilities and a sophisticated user interface to find and listen to broadcasts (SW/MW/HAM/VHF/UHF). If you do have a HAM radio you can link it to the SDR via the PC. For example my HAM radio is a decent bit of gear but it doesn't have a spectrum analyser/Panoramic display, the SDR adds that capability to my HAM radio which can then transmit on those freqs if desired. In a prepper sense, this kit allows you to monitor the HAM bands. You'll need simple wire antennas (to cover different bands) to pick up the signals.
Caveat, I'm not a stranger to comms but I am new to HAM/SDR, that said you don't have to be a genius to see the benefits of SDR. I bought an RSP1A and it includes the SDR Uno software which does all the signal processing and display on the PC.
Here's a quick intro without too much geek speak (unlike most HAM radio videos!)
Hi. Did you purchase the RSP1A locally or o/s. Currently I am just using a $30 dongle, using HDSDR software, but is only covers limited bands
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Post by milspec on Oct 18, 2019 22:33:19 GMT 10
I bought it from an Aussie supplier.
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kiwi
Junior Member
Posts: 45
Likes: 52
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Post by kiwi on Oct 19, 2019 3:12:53 GMT 10
What was the company and price pls
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Post by milspec on Oct 22, 2019 9:57:08 GMT 10
I took a break from site prep to begin the installation of my HAM radio antenna. The antenna is a 102ft G5RV in an inverted V using 40mm PVC pipe as the riser for the centre of the V. The antenna ends are attached to two big trees about 130ft apart. Ive sunk an earth rod near the end of the ladder line and the coax feed has 10 x 6" turns where it meets the feedline via a lightning arrestor. The RG58 feedline itself is buried directly in the earth where it travels from the mast to the house. The pvc became appropriately rigid once fixed with guy wires. It worked out well with only 1 of 4 guy wires being attached the the ground, as the other fix points were fence posts, trees and the eaves of the house.
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kelabar
Senior Member
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Post by kelabar on Oct 22, 2019 14:03:08 GMT 10
Thanks for this info, milspec.
I'm a complete technophobe but this sounds really good.
With an antenna, an SDR thingy and a PC you end up with what is basically the equivalent of a multi-thousand dollar scanner.
The drawbacks are the need to change antennas to receive different wavelengths and the fragility of PCs as opposed to more rugged, purpose-built comms gear.
Does that sound about right?
I'll speculate here because my comms knowledge, despite several attempts to learn more, only includes wiring up a CB. Possibly morse to text software could be integrated, maybe translation software as well. I would imagine recording of signals would be possible. This would allow saving of incoming signals which could later be processed if the PC wasn't up to doing it in real time. And with the appropriate gear it seems this could work as a transmitter as well, including in the restricted wavelengths. (And pirate radio makes a come-back!)
The ability to hear what is going on elsewhere will be critical in any SHTF situation. This sounds like a very capable low-cost system.
The Wikipedia page says this: - A basic SDR system may consist of a personal computer equipped with a sound card, or other analog-to-digital converter, preceded by some form of RF front end.
I've heard of sound cards but what are other 'analog-to-digital converters'? And I assume an 'RF front end' is an antenna?
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Post by milspec on Oct 22, 2019 14:22:21 GMT 10
kelabar the SDR provides the Rf front end and A/D conversion, the pc software then does the rest. Soundcards are not used with the RSP1A other than for letting you hear the signal audio. I believe most ham setups will use a multiband antenna or a mix of antennas. The SDR I have will show the signals present in a 10 Mhz bandwidth rather than finding and tuning into signals like a scanner would, but I agree than the panoramic display of the spectrum is a bit like the functionality of a scanner albeit with the need to select the active frequencies on order to hear them.
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kelabar
Senior Member
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Post by kelabar on Oct 22, 2019 16:05:33 GMT 10
Excellent. Thanks.
My bad. Poor jargon. I probably should have said "receiver" or "radio" not "scanner". I really don't know this stuff.
It works differently to how I thought but still gives the same functionality. Also easier than I thought. Great. I'll look into it more.
Also feel free to dumb-down the language. I am struggling with even the basic info here so others might be too.
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frostbite
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Post by frostbite on Oct 24, 2019 4:22:03 GMT 10
I've been hearing the 'preppers need ham radio' mantra for 40 years, but I still can't see what purpose ham or long range radio has apart from curiosity value.
What relevance to your local situation does intel from thousands of km away have?
Willing to be edumicated on the subject, if anyone can put up a rational argument.
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Post by milspec on Oct 24, 2019 6:06:20 GMT 10
I've been hearing the 'preppers need ham radio' mantra for 40 years, but I still can't see what purpose ham or long range radio has apart from curiosity value. What relevance to your local situation does intel from thousands of km away have? Willing to be edumicated on the subject, if anyone can put up a rational argument. In my book ham radio is useful for a few reasons: A) News about whatever SHTF within the state and district as well as news from outside your borders if it is a global issue. This news might well influence how you plan your own survival strategies or (importantly) how you react to third parties you encounter after SHTF, bearing in mind that the post SHTF dynamics will continue to evolve - ongoing news might be key to your long term survival. B) Information, 2 way comms gives you the potential for finding information you may not possess yourself. C) 2 way comms with your own people over longer range than you're going to get with a UHF CB.
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