Newbie request for sub $500USD wideband listening equipment

Boombox

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Can anyone fill me in on what frequencies would most likely be used in an emergency situation?
CB might be the best bet on that question in general. Hams probably would use HF, as VHF is basically line of sight only and if it's a SHTF situation repeaters might not be working. So a lot of it probably would depend on your local terrain.
 

KevinC_63559

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25 kHz, 11991.7 meters & 1.3 GHz, 0.23 meters. Pretty big span to ask of one antenna. kHz to several megaherts yes. Too much to dive into here and covered better elsewhere. A wire antenna, etc. is best for lower freqs., and VHF, UHF specific antennas for those freqs. Ever see a cop car with 37 antennas on the trunk lid? Some longer and some just a stub. There's a reason. Or a piano with its range of long to short string sets.
Preelectors still have a place. The rsp's should have that pretty much handled in the box.

Just remember. Below, you hint that you want to use only one antenna. Multiple ports will let you use one for the receivers inherent sensitivity and another for a bias-t preamp. If you remove power (bias-t off) from the lna then you get very little signal. The lna does not switch to bypass its circuitry to straight-through to the antenna. It needs to be on all the time when you use that antenna port. If the port were turned on hooked to a loop antenna directly, you would short out the bias-t circuit. And that wouldn't be a good thing.


Diversity reception. That's the term. Was big on car stereos at one time. FM frequency strength could change in just a few feet of driving. Building reflections or blockage, whatever. Diversity selected the better signal and switched to that antenna. Not much personal experience with it. For HF, It could be a big advantage with 2 identical antenna separated by a distance during heavy fade periods.

Yeah, I agree. Have actually been thinking about 2 antennas, a SW one, likely an active loop, to get started and to learn on, and then a bit later a Discone to expand the frequency range of the rig.

That brings me to my current plan:

Buy a RSPdx and marry it to a Cross Country Wireless pre-amp. When used with their 12V Bias T power injector, it is advertised to have a 50kHz to 150Mhz range. (Apparently using the builtin 4.7V Bias T reduces that low end to 500kHz) That feels pretty outstanding to me for antenna purposes. The combo keeps me on budget and provides a bit left over for lead in wires and experimenting on the physical loop design.
 

KevinC_63559

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CB might be the best bet on that question in general. Hams probably would use HF, as VHF is basically line of sight only and if it's a SHTF situation repeaters might not be working. So a lot of it probably would depend on your local terrain.

Actually contacted my state emergency center. They use between 2.3MHz and 8MHz for their communication, so I should be able to listen in with anything capable of handling the SW range.
 

KevinC_63559

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CB might be the best bet on that question in general. Hams probably would use HF, as VHF is basically line of sight only and if it's a SHTF situation repeaters might not be working. So a lot of it probably would depend on your local terrain.

Locally we are hilly. My 4 acre lake is about 60 feet below where my house is. My 900 foot driveway entrance is one of the highest spots in the county around 1000 feet above sea level.
 

belvdr

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I would build slowly. Only add the preamp if you need it. Where I’m located, I use a dual band yagi and hear everything well.
 

mitbr

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I have an SDRplay RSPDX and think it is the best receiver I have ever owned and have been into radio since the seventies!!!! This sdr has three ant inputs switchable within the software. I use both sdruno and sdr console for software to run the sdr. SDRPlay is getting ready to release new software called SDRConnect shortly. I guarantee you wont be disappointed with SDRPlay.They are an outstanding company buy it from HRO.
Tim :cool:
 

KevinC_63559

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I have an SDRplay RSPDX and think it is the best receiver I have ever owned and have been into radio since the seventies!!!! This sdr has three ant inputs switchable within the software. I use both sdruno and sdr console for software to run the sdr. SDRPlay is getting ready to release new software called SDRConnect shortly. I guarantee you wont be disappointed with SDRPlay.They are an outstanding company buy it from HRO.
Tim :cool:

Thanks. We are T-Minus 7 days for pulling the trigger. Friend has old prof that teaches HAM he is going to meet next week and review our thoughts with.
 

belvdr

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I have an SDRplay RSPDX and think it is the best receiver I have ever owned and have been into radio since the seventies!!!! This sdr has three ant inputs switchable within the software. I use both sdruno and sdr console for software to run the sdr. SDRPlay is getting ready to release new software called SDRConnect shortly. I guarantee you wont be disappointed with SDRPlay.They are an outstanding company buy it from HRO.
Tim :cool:
SDRconnect may bring my RSPdx back to life on my Linux machine, if they ever release it. :D
 

Dirk_SDR

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OK - spent the last day or so going down the SDR rabbit hole.

Been looking for dual port units to avoid having to have an antenna switch (one for < 30MHz, one for > 30MHz). I know I could buy an Antenna switch, but that is yet another box to fail (Did I say that out loud?).

Specifically when I looked at the Airspy HF+ the older model has dual antenna ports, the newer faster-better-cheaper Discover unit only has a single antenna port. Am I right in presuming I'd need to add a switch for (at least) 2 antennas? Not a killer issue - just hate surprises. Apparently has 18 bit converters. $169 List for the Discover, $199 for the older Dual Port

The Nooelect NESDR Smart v5 has a broader range (100 kHz to 1.75GHz vs. 0.5kHs to 31MHz for the Discovery), but a single antenna port like the Discovery so presumably the same switch need. Kits are cheap at $115 and come up with the Ham It Up Upconverter - which for the uneducated like me is confusing. Why do I need an upconverter???

Also stumbled across the RTL-SDR Blog V3 (and its clones) - very inexpensive ($43 kit), but concerned about it only going to 24MHz in direct sampling mode then needing to be tweaked (setting changed) to go higher. Guessing that would be inconvenient.

Finally looked at the RSPDuo - 3 antenna inputs - priced around $300, 1kHz - 2GHz range. 14 bit converters.

Thoughts?

Reminder: $500 budget
Ok, that's a fine rabbit hole, but with many questions...
One of the "wideband" characteristics is that those SDR receivers are e.g. able to receive from ULF to SHF. That means, you will not be lucky with one antenna up to and another above 30 MHz, because even below 30 MHz you'll need perhaps 4 or 5 antennas, if you want to be active from 500 Hz to 30 MHz. Above 30 MHz that's the same.
So an antenna switch will not help: you must change antennas.
Therefore I think, its not an important point, whether a receiver has one or two antenna ports, at least specific for frequency ranges. Another point is, whether 2 antenna ports of a receiver have different properties, e.g. high impedance vs. 50 Ohm.
Upconverter: the "normal" simple RTL-SDR receivers could receive from 25 MHz up. So they could not receive SW and lower. An upconverter helps to receive also VLF, LF, MF and HF with these receivers. But if you would buy a receiver like the Airspy HF+ Discovery, you would not need an upconverter. An upconverter is also not necessary for RTL-SDR sticks with "direct sampling mode" like the RTL-SDR Blog V.3 or the Nooelec NESDR SMArt v5.
 

Boombox

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Locally we are hilly. My 4 acre lake is about 60 feet below where my house is. My 900 foot driveway entrance is one of the highest spots in the county around 1000 feet above sea level.
Well, if you're considering dumping any money into VHF maybe a good thing would be to get a scanner or other affordable (? - I don't know how affordable scanners are anymore, maybe a VHF capable SDR would work) VHF receiver and listen. See if anyone is actually on. Last time I checked the local 2 meter Band during a rare weather event it was deadsville. 25 years ago the band was active almost 24/7. YMMV.
 

ArloG

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You're missing encryption changes eventually render scanners obsolete and as I understand you have to buy the unlock code to enable them.
Where scanner capabilities soon are natively limited by design. SDR I/Q will allow software decoders such as DSD+ and others are simply updated. Scanning and trunking and lots of things can be done in SDR software.

To add. I recently lent my buddy my RSP2. Strung 50 feet of wire to a tree with insulators. Threw on a spare balun from the box-o-tricks.
Installed the drivers on his Dell desktop. BTW, He's a CB-er and trucker.
Installed HDSDR on the computer. In 15 minutes (or 2 hours after a few beers) I went home and him and his wife had a blast for days.
Installed a few other programs. SDR-Conlole and SDRUno.
Being noobs they did like HDSDR due to the simplicity of use. Showed them how to use fldigi and Artemis for signal id.

As for Dirk. Hellyeah multiple ant. ports are a plus. And should matter.
 

Dirk_SDR

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As for Dirk. Hellyeah multiple ant. ports are a plus. And should matter.
It depends on the kind of antenna ports.
If you have multiple ant. ports for 5 different frequency ranges like on this SDR receiver:
... they make no sense for me and make the usage of such a receiver complicated.
But if the ant. ports are e.g. for different kinds of antennas (e.g. Hi-Z) or for more than one tuner like on the SDRduo here:
... they are of course a plus.
 

majoco

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Marine HF radio emergency frequencies...in kHz USB. 8291 is the one commonly recommended as is has better propagation at most times of the day and night.

21824125 621582911229016420
 

Boombox

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You're missing encryption changes eventually render scanners obsolete and as I understand you have to buy the unlock code to enable them.
Where scanner capabilities soon are natively limited by design. SDR I/Q will allow software decoders such as DSD+ and others are simply updated. Scanning and trunking and lots of things can be done in SDR software.
While your point is well taken, most VHF/UHF ham frequencies on 2 Meters and 440 Mhz aren't encryptied, and as the OP was looking for a radio for emergency situations, I think his taking a listen to see if there is any local or regional 2 Meter or 440 Mhz activity would probably be advisable before buying a 2 Meter / 440 Mhz radio after becoming a ham.

If he can do it with an SDR, that would work for monitoring bands and ranges ahead of time..

For emergencies, if I were in his shoes, HF would be the way to go. And HF includes 10 Meters, which has local reach as well as worldwide reach, depending on antenna used. If he has buddies within the region he would want to keep in touch with during a SHTF situation, 2 meters would work, depending on antennas and distance, of course.
 
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