|
if the rtl sdr blog stick is out of stock, this may be suitable too http://www.thumbsat.com/thumbnet-radios Ignore their goofy startup project on the whole F connector, linear regulator (less noise but more heat), common mode chokes on the USB lines (less interference from computer)
|
#
?
Sep 14, 2016 00:33
|
|
|
|
| # ? May 23, 2024 10:47 |
|
|
To be fair, marketing can be confusing as hell with FRS radios. Most don't really tell you that of those 22 channels, 1-7 are shared with GMRS and 15-22 are GMRS only, which requires a license. (does anyone actually get one or get punished for not having one, given the ubiquity?) I have one lying around that at least lets you turn the power down to <=500mW so you can use channels 1-7 as FRS without a license, but I bet most people don't even know that keeping the power turned up above 500mW is a violation. Edit: This is honestly the main reason I look the other way with amateur HTs programmed with FRS/GMRS frequencies. The guy with his thumb on the PTT on one of those at least knows a little more about what he's doing than the Average Joe, so long as he's not doing anything stupid, it's all the same radio signal. xergm fucked around with this message at 02:37 on Sep 14, 2016 |
|
#
?
Sep 14, 2016 02:32
|
|
|
hogmartin posted:What city are you in? Harrisburg, PA I checked around and found 2 local ham radio clubs, which also operate repeaters. I'll keep looking at the cheaper radios to jump into the hobby with. Worst-case, I'd have a beat around 30$ Fm radio with NOAA stations. As for the beach communications, I've tried the "30 mile" Motorolas and some definitely cheap walkie talkies before, and nothing but garbled voice and static. At maximum distances of .5 of a mile with buildings, trees, and sand dunes in between.
|
|
#
?
Sep 14, 2016 02:42
|
|
|
xergm posted:Edit: Pretty much my logic as well. If you're putting out a clean signal that someone receiving wouldn't be able to tell apart from the type-approved devices and keeping the power where it belongs, what's the harm? I can't blame someone for not wanting to purchase and carry an extra device for purely legal rather than technical reasons.
|
|
#
?
Sep 14, 2016 16:23
|
|
|
wolrah posted:Pretty much my logic as well. If you're putting out a clean signal that someone receiving wouldn't be able to tell apart from the type-approved devices and keeping the power where it belongs, what's the harm? I can't blame someone for not wanting to purchase and carry an extra device for purely legal rather than technical reasons. Well, I mean, teeeeeccchhhhnically you're still above the allotted ERP even if you do 500mw your HT, since your antenna has positive gain most likely and the restrictions include having an irremovable antenna yadda yadda - you are a bit better shot RX/TX wise both vs. the type-approved devices. However I think it's such a minute, harmless differentiation that literally nobody ever has given a gently caress unless you're like on a mobile pushing 45 watts on FRS 1 talking poo poo.
|
|
#
?
Sep 15, 2016 01:37
|
|
|
There's much worse things you can do. I'm sure we've all done some dumb things for fun at least once with our radios. At least for me, juvenile humor is what led me to ham radio in the first place. It started out with me watching some guys with a modded Yeasu VX-7R messing with a Taco Bell drive-thru. I think it's the ingrained tinkerer/hacker nature to play with things.
|
|
#
?
Sep 15, 2016 03:47
|
|
|
xergm posted:I think it's the ingrained tinkerer/hacker nature to play with things. This is certainly one of my primary motivations for looking deeper into this hobby. Honestly, I very well may listen to one conversation over a 2 meter repeater, and entirely lose interest. Perhaps sometime in the future though, I can help a poor boy scout get his radio merit badge.
|
|
#
?
Sep 15, 2016 15:19
|
|
|
As for my own stupidity, upon reading the article for SAME (those emergency alert noises you hear whenever there's bad weather or an AMBER alert), I thought "Hey, this article is pretty detailed on how it works. I wonder if I can do that." One evening later, it turns out it's not particularly hard to do. I cooked up a program to output the raw PCM data. I may or may not have tested this with one of those weather radios to see if I did it right.  I have the source code if anyone's curious. I lost the original but decided to rewrite it a year ago since I've never seen anyone else write a similar program. I felt pretty proud of my hackery. Edit: Source It's completely barebones, basically just a proof-of-concept. xergm fucked around with this message at 16:06 on Sep 15, 2016 |
|
#
?
Sep 15, 2016 15:59
|
|
|
xergm posted:There's much worse things you can do. I'm sure we've all done some dumb things for fun at least once with our radios. xergm posted:As for my own stupidity, upon reading the article for SAME (those emergency alert noises you hear whenever there's bad weather or an AMBER alert), I thought "Hey, this article is pretty detailed on how it works. I wonder if I can do that." I wonder if you can get enough of a signal to trigger a nearby receiver while within Part 15 limits. Could be fun to screw with friends. Maybe even could make it work with those Raspberry Pi transmitter hacks. They only do 12.5kHz FM AFAIK where weather radio is 25kHz, but there might be enough tolerance in the SAME decoders to get away with it. Drop a Pi 3 set up for your target's WiFi near their weather radio and now you can send them Volcano Warning alerts from anywhere in the world wolrah fucked around with this message at 20:21 on Sep 15, 2016 |
|
#
?
Sep 15, 2016 20:17
|
|
|
wolrah posted:Yup, basically it comes down to "don't be a dick" IMO. Screwing with drive throughs is of course funny, but definitely on the dick side of things. Not saying I'm innocent, but I won't defend it in the same way as I'll defend using the "wrong" radio. Weather radio is is up at 162MHz unless I'm completely misunderstanding what you're saying...
|
|
#
?
Sep 15, 2016 21:42
|
|
|
fordan posted:Weather radio is is up at 162MHz unless I'm completely misunderstanding what you're saying... He's talking signal width not location.
|
|
#
?
Sep 15, 2016 23:44
|
|
|
wolrah posted:Yup, basically it comes down to "don't be a dick" IMO. Screwing with drive throughs is of course funny, but definitely on the dick side of things. Not saying I'm innocent, but I won't defend it in the same way as I'll defend using the "wrong" radio. Is there any power level that would be within part 15 limits? One of the stipulations is "Can not cause harmful interference" and I would certainly think the FCC would classify spoofing a WX alert as harmful interference regardless of power level. If I ever tried this again, I'd probably make sure it was in a Faraday cage. One of these days I need to actually fiddle with GNU radio. If it's as powerful as I've heard, decoding SAME on GNU radio should be possible. My next project should be to see if I can get one of the SDR dongles connected to my discone constantly search through FM broadcast and NOAA WX listening for those alerts. xergm fucked around with this message at 15:07 on Sep 16, 2016 |
|
#
?
Sep 16, 2016 15:04
|
|
|
Consumer FM transmitters are a thing, so clearly it's possible to get an audible signal at a short range within part 15. I know a few years back there was a big crackdown because a lot of those devices were hugely exceeding the limits to be usable for hundreds of feet where the replacements that were actually compliant crapped out at 10 or less. I'm pretty sure the part 15 power limits are the same from 88-215 MHz. No idea on if they'd call it harmful interference if you used a channel that wasn't active in your area. You're not interfering with anything at that point, at least any more than using the aforementioned FM transmitters would be. Spoofing an alert obviously makes it grayer, but we're also talking about a short-range transmission so depending on where your target lives it might not even reach anyone else at all making it kind of a moot point. edit: Wow part 15 has a lot of subparts and sections. The overall limit from 88-216 is 150mV/m @ 3m. The FM Broadcast range from 88-108 allows up to a 200kHz wide signal at 250mV/m @ 3m, so a consumer FM transmitter can use a bit more power. Short-duration intermittent operation for control or alerting purposes from 130-174 can go up to 3750mV/m @ 3m. Whether a SAME code would count as alerting is arguable. Voice is not allowed in this application, only data and control signals up to 5 seconds if automatic and up to 10 seconds if manually triggered. At low power if I was confident I wasn't going to screw with anyone who would generate a FCC complaint I'd call this close enough. edit2: Nope. § 15.205 Restricted bands of operation. posted:(a) Except as shown in paragraph (d) of this section, only spurious emissions are permitted in any of the frequency bands listed below: I guess that settles it, part 15 devices could be nearby on the spectrum but intentional transmission on those specific frequencies is banned outright. wolrah fucked around with this message at 16:51 on Sep 16, 2016 |
|
#
?
Sep 16, 2016 16:28
|
|
|
Be careful trying to trigger stations, I wouldn't be completely positive that no broadcast EAS receivers are tuned to weather stations.quote:On May 20, 2010, NOAA All-Hazards and CSEPP tone alert radios in the Hermiston, Oregon area, near the Umatilla Chemical Depot, were activated with an EAS alert shortly after 5 p.m. The message transmitted was for a severe thunderstorm warning, issued by the National Weather Service in Pendleton, but the transmission broadcast instead was a long period of silence, followed by a few words in Spanish. Umatilla County Emergency Management has stressed there was no emergency at the depot.[33] I can think of a few choice words in Spanish I might say if my experiment went too well.
|
|
#
?
Sep 16, 2016 18:01
|
|
|
Trabisnikof posted:Be careful trying to trigger stations, I wouldn't be completely positive that no broadcast EAS receivers are tuned to weather stations. The more you know! I wasn't aware that there were other systems that scanned for EAS alerts. Makes sense though. wolrah posted:I guess that settles it, part 15 devices could be nearby on the spectrum but intentional transmission on those specific frequencies is banned outright. Nice find! As for doing that in the broadcast FM band, I would certainly think that spoofing those would be pretty cut and dry concerning interference. I'd had never actually considered using one of the portable FM transmitters to do it. I'm not sure if those WX radios even scan the FM broadcast signals for those messages, just NOAA. It is, after all, called the Emergency Alert System. The FCC permits you to use all available means in an actual emergency, not so much for faking one. I'm surprised with so many experimental SDRs capable of transmitting, we haven't seen radio phreaking become a thing like phone phreaking was back in the day. xergm fucked around with this message at 19:00 on Sep 16, 2016 |
|
#
?
Sep 16, 2016 18:56
|
|
|
xergm posted:The more you know! Yeah the system is set up with redundant receivers listening to other nearby stations so usually the risk of someone overpowering the local FM station is pretty low. But I could also believe there could be some hardware out there set by default by someone to listen on a weather band that's no in use and it would be my luck that said receiver would be near where ever I decided to test. Another good eas goof: quote:During September 2010, the staff of KCST-FM in Florence, Oregon noticed that the station's EAS equipment would repeatedly unmute as if receiving an incoming EAS message several times a week. During each event, which was relayed from KKNU in Springfield, the same commercial advertisement for ARCO/BP gasoline could be heard, along with the words "This test has been brought to you by ARCO". Further investigation by the primary station transmitting the commercial revealed that the spot had been produced using an audio clip of an actual EAS header which had been modified to lower the header's volume and presumably prevent it from triggering false positive alert reactions in EAS equipment. The spot was distributed nationally, and after it had once been identified as the source of the false EAS equipment trips, various stations around the country reported having had similar experiences. I also think a few news stations have gotten in trouble because they idiotically played a clip of someone else accidentally playing the eas tones on air. edit: radio phreaking is totally a thing now  This video goes over blind decoding of sat signals with gnuradio tools https://youtube.com/watch?v=drsgh_PZmJ8 Trabisnikof fucked around with this message at 19:08 on Sep 16, 2016 |
|
#
?
Sep 16, 2016 19:05
|
|
|
Trabisnikof posted:Be careful trying to trigger stations, I wouldn't be completely positive that no broadcast EAS receivers are tuned to weather stations. If you live in a downtown apartment for example you definitely have to be a lot more careful about any experimentation in non-amateur bands. Dinking around intermittently at low power on an unused frequency is pretty much harmless and unlikely to catch the attention of anyone else at all, much less someone you wouldn't want the attention of. Causing any kind of problem for a major licensed user is a good way to have people in vans with antennas looking for you. xergm posted:As for doing that in the broadcast FM band, I would certainly think that spoofing those would be pretty cut and dry concerning interference. I'd had never actually considered using one of the portable FM transmitters to do it. I'm not sure if those WX radios even scan the FM broadcast signals for those messages, just NOAA.
|
|
#
?
Sep 17, 2016 00:24
|
|
|
Sniep posted:Well, I mean, teeeeeccchhhhnically you're still above the allotted ERP even if you do 500mw your HT, since your antenna has positive gain most likely and the restrictions include having an irremovable antenna yadda yadda - you are a bit better shot RX/TX wise both vs. the type-approved devices. However I think it's such a minute, harmless differentiation that literally nobody ever has given a gently caress unless you're like on a mobile pushing 45 watts on FRS 1 talking poo poo. What about ditching frs/gmrs for MURS frequencies and setting those presets to low power? I'm sure its not technically kosher because the hts are not type accepted but murs has a power limit of 2 watts and the low power setting on most hts would fall within that limit. I used to use murs with some friends here in town but lately the migrant workers a town over have been running pirate Norteno music stations on the freqs. I poo poo you not. MullardEL34 fucked around with this message at 08:48 on Sep 17, 2016 |
|
#
?
Sep 17, 2016 08:43
|
|
|
Technically speaking, if the radio is not type accepted for the service, it's not allowed. I know some of the Chinese brands are actually type accepted for part 90 which is Land Mobile Radio Service. My Wouxun is part 90 approved, for instance. MURS is part 95, I believe. I don't know of any amateur marketed HTs that are also type accepted for MURS use, but it's really only a big deal if an inspector comes and asks to look at your HT. If an inspector is already asking to do that, it's probably not the type acceptance he was going to nail you for (you were doing something else stupid), but he'll certainly add it to his list of violations.
|
|
#
?
Sep 19, 2016 17:01
|
|
|
Could not put it any better. Squawk away, offend no one.
|
|
#
?
Sep 19, 2016 23:47
|
|
|
Speaking of FM broadcast radio transmitters, I've actually been wanting one so I can send audio from my computer or cable box to the FM radio in my shop from the house. Does Ramsey have a monopoly on kits for this, or does anybody else make them?
|
|
#
?
Sep 23, 2016 01:09
|
|
|
Well, Ramsey's dead, you don't even have them any more. But uh....google "fm transmitter" on ebay and you will find a wide assortment from $3 flea-powered (and thus probably the only legal ones to use) one-board transmitters, up through 10 watt tunable blowtorches for $80. If you want to go hard, you can get a 300w amplifier kit for under a hundred bucks! .... Yeah there's a bunch of blatantly illegal-to-use stuff on eBay. Stick with low power and you should be fine.
|
|
#
?
Sep 23, 2016 01:25
|
|
|
gently caress, I didn't know Ramsey died in between now and the last time I looked at their site. That sucks!
|
|
#
?
Sep 23, 2016 01:33
|
|
|
I'm super depressed about the ramsey thing since I wanted to buy and build their qrp amp.
|
|
#
?
Sep 23, 2016 01:36
|
|
|
Every hamfest i've been at for the past year or so has had guys with several boxes full of unbuilt Ramsey kits for pennies on the dollar. i got some cool 2m -> 10m receiver converters and tone decoders for a buck apiece We need a good rf kit company to fill the vacuum. Shenzhen protoboards and shields for a buck apiece are great, but I want little preamp and transmitter kits. Or maybe since it's 2016 and we all know about things like markup, how about a service that'll sell you a PCB and pre-fill a Mouser cart with all the parts? We have mail order PCBs of far higher quality than we can cut at home now; leverage that and make the business that instead of marking up electrolytics for people that can't pick them out on Digikey
|
|
#
?
Sep 23, 2016 01:41
|
|
|
To that end, perhaps an open source type solution that provides PCB artwork, schematics, and fills the mouser cart. You could make the boards yourself or send the files off to osh-park. Kind of like a cross between wikipedia and github with added API's to interface to parts sellers and board houses.
|
|
#
?
Sep 23, 2016 01:59
|
|
|
So, I'm going for an upgrade to General soon. I picked up a WRL Galaxy V transceiver on ebay for $40  And a Heathkit HP-23A power supply that I got locally for $20 to run it. The Galaxy still needs one more 12VDC rail at 1A to make it work. I can do that... The PSU and Transceiver will need a full electronic restoration. I'll post my progress here. MullardEL34 fucked around with this message at 10:46 on Sep 24, 2016 |
|
#
?
Sep 24, 2016 10:41
|
|
|
jesus christ livin up to your name lol Neat looking radio, never seen one in the flesh.
|
|
#
?
Sep 24, 2016 10:43
|
|
|
Jonny 290 posted:jesus christ livin up to your name lol A neighbor William Nick, had one that he used until he passed in 2004. Hanging out at his house gave me the itch. Got me into vintage Color TV...  Regular Maintenance for a 1967 Zenith color TV... 
|
|
#
?
Sep 24, 2016 11:39
|
|
|
I can't bring myself to buy consumer bullshit designed to plug into an iPhone or mystery boxes from China that are quite far from complying with Part 15... Adafruit to the rescue: https://learn.adafruit.com/adafruit-si4713-fm-radio-transmitter-with-rds-rdbs-support/overview
|
|
#
?
Sep 26, 2016 18:54
|
|
|
You can add me to the op, new ham: KM6FJD. I started this reddit thread a couple weeks ago, is there anything anyone wants to add here? https://www.reddit.com/r/amateurradio/comments/50s69h/you_have_an_ht_and_a_tech_license_what_now/ It's basically "List all the things you can do with an HT and a tech license before spending all your money on HF stuff" Current list: * Scan and Listen to your local repeaters noting what is active * Program your HT with those repeaters * Simplex ragchew * Duplex ragchew * Attend a net on a local repeater * Talk with people very far away via a WINS repeater * Exchange morse code messages (over simplex FM lol) * Attend a local club meeting * Pick up a small TNC and play around with APRS (Mobilinkd TNC project and UV5R-TRRS project) * Make a small tape measure yagi antenna and try working an amateur satellite during its fly over * Foxhunt with your tape measure yagi * Experiment with packet radio and bounce signals off the ISS on 2m * Join SKYWARN - become a trained NWS spotter (not chaser). If your area has a severe weather net, join accordingly and contribute any reportable events. * Build a slim jim antenna for further vhf / uhf range and see if you can pick up anything new * Experiment with IRLP, EchoLink and D-Star * Go hiking and participate in Summits on the Air (SOTA) * Participate in Field Day * Volunteer and work a local event * Hook up a computer or phone to decode SSTV transmissions from the international space station * Get a Raspberry Pi, a TNC-Pi, and the cable to connect your HT to the TNC-Pi, then set up a Winlink terminal. * Using the setup from above and a USB GPS receiver, create an APRS iGate. * Get another Raspberry Pi and start messing around with rpitx. * Learn Morse. * Build some Yagis and work SO-50 (input 145.850 FM, PL 74.4 for the initial hit, then PL 67.0 for the 10 minute communication window, output 436.795 FM ) and ARISS (input: 437.800 FM, output 145.800 FM). The latter is NOT a repeater. It is a live amateur radio-to-the International Space Station link--you will be talking to actual astronauts/cosmonauts in low earth orbit. You may need two HTs for best results, but even one HT with dual-band capability or a band-split operation can do the trick. * Study for General / Extra First Time Caller fucked around with this message at 20:46 on Sep 28, 2016 |
|
#
?
Sep 28, 2016 18:12
|
|
|
Can't think of anything to add to the list off the top of my head, looks fairly complete. How do you accomplish duplex ragchew with a single HT?
|
|
#
?
Sep 28, 2016 19:30
|
|
|
AbsentMindedWelder posted:Can't think of anything to add to the list off the top of my head, looks fairly complete. I guess I meant have a conversation on a repeater
|
|
#
?
Sep 28, 2016 20:44
|
|
|
AbsentMindedWelder posted:Can't think of anything to add to the list off the top of my head, looks fairly complete. He clarified his point, but i'll be smug about my favorite feller on the HT shelf here:  HTs used to be way better. Full duplex, great front end, 5 watts on a 7.2V battery. And it's new enough that chirp can program it!
|
|
#
?
Sep 28, 2016 23:38
|
|
|
Passed the technician exam a few weeks ago. Getting sent my grandfather's old handset, no clue what it is but looking forward to listening to old men complain about traffic soon. Gildiss fucked around with this message at 03:31 on Dec 22, 2016 |
|
#
?
Sep 28, 2016 23:55
|
|
|
Gildiss posted:Passed the technician exam a few weeks ago, KM4WLW. Congrats old man. That is an awesome way to get involved. (seriously.....it's great to get gear that means something to you personally) How's your colostomy doing?
|
|
#
?
Sep 29, 2016 01:03
|
|
|
Gildiss posted:Passed the technician exam a few weeks ago, KM4WLW. young hams complain about traffic. average hams complain about obama and their ailments.
|
|
#
?
Sep 29, 2016 03:40
|
|
|
winter in denver is cool because a bunch of plow drivers are hams and on snow nights they mob up on the repeaters and piss and moan while their trucks warm up. Kinda fun to hang with night crew. Quite a few fixed-route truckers that run stuff over from Hays or Wichita too, they're always rolling out at 3am
|
|
#
?
Sep 29, 2016 04:13
|
|
|
Speaking of full duplex, since I have decommissioned my 2m dstar repeater, I look forward to tuning the duplexer up to the RX/TX freq of a repeater I like to frequent @ night so I can run full duplex audio with two radios. People on this machine like to talk over each other frequently with humorous comments, so this should prove to be quite fun. I'll probably have to use headphones or something so I don't cause audio feedback.
|
|
#
?
Sep 29, 2016 14:55
|
|
|
|
| # ? May 23, 2024 10:47 |
|
|
Jonny 290 posted:He clarified his point, but i'll be smug about my favorite feller on the HT shelf here: Make HT's Great Again. Speaking of HT's, anyone play with commerical gear? I recently picked up a EF Johnson 5100 to do P25, but having a hell of a time doing anything with it. It has FPP enabled and I can program convention FM channels, but not P25. I have the software and can read the radio id and options, but everytime I try to download the config the radio restarts and the software throws up errors. I hear part of it may be do to the fact this is an early version of the 5100, based off of the Motorola Astro Sabre, and that it doesnt like modern OSs or multi core cpus. Anyone ever program one of these? I guess they are popular with CAP, but theres no CAP where I live anymore. uli2000 fucked around with this message at 00:48 on Sep 30, 2016 |
|
#
?
Sep 30, 2016 00:36
|
|
