I’d like to know from the general SDR-ING public, how do you SDR generally and with what?
Ofcourse I’m sure we all have some RTL-SDR variant but what is the main use and purpose of your SDR? Are you like me and use it for anything/everything or leave it as a single-purpose device?
Scientific use/reverse enginering? - Determining channels, modulation querks or problems with RF devices?
Work use? - Wireless surveying, trunked radio testing or monitoring?
General listening? - HF/UHF/VHF voice and data use?
Utility use? - As an AIS receive device for a boat or ADSB RX for an aircraft?
For me generally - my oldest RTL-SDR (generic USB 28xx DVB reciever I bought in 2009/2010 clone) is used for AIS or ADSB RX attached to a PI 4 with OpenCPN or running dump1090 - no filters, no LNA (bring the rage) and hand made dipoles on a switch, situated on a small boat.
Another RTL-SDR v4 usually in my pocket or desk, for general listening or portable for AIS and ADSB with an android device, sdrangel or MagicSDR, with about 60cm of 50ohm speaker wire and a crocodile clip on a BNC adapter or mini UHF/VHF ducky with a USB-C adapter as needed - occasionally listening and testing UHF/VHF handhelds, sometimes HF and whatever else takes my fancy at the time.
I’m sure we’ve all seen the RTL-SDR blog with a million things it can be used for, I just wonder if anyone uses it only for casual listening OTG or a single functional purpose.
Personally, I keep one handy RTL-SDR for general use, and dedicate other RTL-SDRs to specific tasks with optimized antennas, filters, and LNAs for max performance.
The philosophy that the antenna and signal preconditioning are more important than the quality of the radio itself seems to ring true most of the time for optimizing reception.
That’s how most of the new products the blog or KrakenRF sells come into existence, by building antennas and signal conditioning circuits, and then realizing others might want them too.
as a kid i got fascinated of receiving signals on both tv and radio’s. Played a lot with walkie talkies and owned a mili band radio that had airband, uhf, vhf short wave cb,…. i could receive so much on the top of the 30 meter high building i lived in. Bought a 27mc tranciever at the age of 13 and had fun until it broke. Then came other things in my life but Started buying 2 cheap tranceivers again 30 yrs later,also a uniden 355clt and ended op buying an sdr v3 which at arrival turned out to be a clone. Still recieved a lot but bias-t etc was not there. Got a genuine v3 with dipole as a set shortly after getting ripped off and every now and then i toss an antenna on the roof and i try to find out new things to receive and purposes to do with it. The digital stuff and pagers are fun to decode. for all other things i often use the quansheng and radtel walkies i also have. My wife does not understand how i can spend many hours with my reciever stuff but atleast i know you all do :}
@bobfalcon79 Very cool that you’re still doing it with more modern technology, I started similarly with my Dad’s CB handheld (a midland something from radioshack he had for a few years) - FM only still very cool in the 90’s.
I know radio is generally an in-the-shack activity for most but I would rather be out and about - Hiking or walking with a pack, walking the dog, travelling from place to place, sometimes driving but more often by public transport, by foot or out on the water - an android phone or UMPC as the host depending on needs (AIS, ADSB, PSK/JS8/etc).
One of the things I find most dissapointing with all SDRs (Even hackrf + portapack) is the fragility of connectors, poor heat dissipation & it’s quite apparent they’re designed for ‘indoor boys’ and static use. Some would say ‘just use a handy-talky with waterproofing’ but these are severly lacking in wideband RX (unless you’re throwing a few hundred into the purchase) or lacking complex protocol support - adding to the daily carry gear list and additional power concerns.
Granted, excess humidity and continued movement of person and device isn’t a general concern for most but working towards a better in-pocket mobile usability; no more cables disconnecting by wiggling or damaged would be a massive boon to the future of SDRs for a variety of users, not just the stereotype is far more useful for everyone - especially those unlicensed & RX only.
I don’t want to carry an overpriced HT, I could see several scenarios where it would be more beneficial to build some RTL-SDR casings with heatsync fins, a lock-in cable mechanisim and a PCB strip antenna, wire or short coiled ducky.
The RTL-SDR v3 is my most ubiquitous SDR. I think I’ve got 7 of them.
Several are in 24/7 monitoring mode in the shack. Honestly, they get used for everything. Lowest frequencies I tend to monitor are Airband. Highest are in the 1.5 GHz range. Most are on some kind of UHF duty - either 400-500 MHz or 770 MHz.
One lives full-time in my carry-on travel bag. Goes everywhere with me. If I have a few extra minutes, I’ll put it out and begin searching the bands for activity wherever I am. Smaller, lighter and draws much less attention than a scanner.
Another RTL-SDR blog kit lives in my car along with a Panasonic Toughbook. Wife’s in the Mall? I’ve got no problem killing time outside I use this one for figuring out who users of various trunked systems are. Set the Toughbook on the passenger seat, listen to where units are being sent by dispatch, drive to the address and see if I can get there before the unit - and boom. Now I know the the Security Company / Trucking Company or I surveil the VIP detail, ha ha.
I’ve got a v3 and v4 RTL-SDR, a NOOELEC, an Airspy HF+, and an RFNM SDR.
I use them to listen to radio – mostly FM with some SW mixed in, occasional monitoring of various devices, as a poor man’s spectrum analyzer, or as some other EE related equipment.
It is not reasonable to expect to find ruggedized devices for outdoor use since that would increase cost rather significantly, and I’m not sure if the volumes would make that worthwhile.
If you want one used outside – you could use a plastic bottle to make a weatherproof enclosure.
I am new to RTL-SDR. Right now I am using mine for general telemetry. I am monitoring my power meter against our solar production. I am also using it for my mailbox monitor. One other thing I will use it or a second one for is to receive HD Radio. The challenge for me is figuring out how to get the raw audio out of the raspberry pi over I2S. Looks like there are a few ways to do it using a virtual cable but have not had time to play with it yet.
I was more thinking as a ** hint hint rtl-sdr ** add-on or accessory to clamp onto the existing casing body, something purchasable for those who need protection or extra cooling for long-term use.
Some aluminium heatsyncs (Low profile raspi CPU sized are best) some cableties, heatsync pads (squishy blue or white kind) epoxy and a project box do fine but the connectors are the real challenge.
Unfortunately I don’t have a workshop, cnc machine or any other cool toys to make my own, 3 repairs in - 2x USB connector, 1x SMA connector.
Are they all running separate antennas or a single multiband, maybe a discone high up?
Having a few you could create a kraken-style system, with a TXCO for time sync, processing and mismatched antennas/placements may be the complicating factors.
So many great potential possibilities and uses for such a simple thing.
Is that only for an onboard speaker or are you monitoring it from elsewhere (pi in the mailbox, laptop/phone/desktop remote)?
I was more thinking as a ** hint hint rtl-sdr ** add-on or accessory to clamp onto the existing casing body, something purchasable for those who need protection or extra cooling for long-term use.
I see 2 different issues here:
thermals
protection from elements
For thermals, it is really the designer’s/maker’s duty to ensure that there is sufficient cooling that the device can dissipate heat reasonably well. Given all the different form factors and the number of different SDRs, i do not see much market for 3rd party SDR specific cooling solution.
Having said that you could just have a fan blowing air over it, or if possible, you could install a heatsink made for some other device.
As for protection from elements, you could just get some enclosure made for something else, and adapt it to your SDR.
but the connectors are the real challenge
I’m not sure what’s the issue here – so you may want to elaborate. You can get all sorts of adapters and cables, and while the ability to solder and make your own connectors/cables could be helpful, it isn’t absolutely necessary. Some years ago I operated the v3 RTL-SDR over a 50 ft long USB cabling that used 10 - 15ft long USB cables and 3 externally powered USB hubs in between.
I also tried an Ethernet based USB extender (2 dongles) but that one didn’t work too well.
I use this one for figuring out who users of various trunked systems are. Set the Toughbook on the passenger seat, listen to where units are being sent by dispatch, drive to the address and see if I can get there before the unit - and boom. Now I know the the Security Company / Trucking Company or I surveil the VIP detail, ha ha.