Messages

16

SDR - Software Defined Radio / Re: Comparing the "KiwiSDR" and the "RaspberrySDR" software-defined radios

« on: January 09, 2021, 0634 UTC »

Thanks for your reply, and yes, I noticed that some versions seem to be different, looking at other's SDR interfaces. I would want a radio that could be customized and interface stays the same, unless I would be interested in a new feature and want to add it myself, sort of like a hardware radio.

I'd guess that some of the differences could be someone using different radios on Kiwi, like OpenWebRX's or FlyDog, variants that have different features and frequency coverage.

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Software / Re: audio editing software

« on: January 07, 2021, 0825 UTC »

I would say Audacity also, though it had a learning curve for me, there's "too much" in it when I just use basic editing.

I'll second the suggestion of the Oldversion of Cool Edit, if you just need to record, edit and save into MP3. Some old versions will use a separate codec pack to add MP3, and I think you can add LAME's MP3 filter, .FLT file to it, and once done you can record a waveform, then save to MP3 easily.

CoolEdit was the best and worked on low end laptops, like a P1, we could record and edit a piece, convert to mp3 at 128k and FTP it to the station over the phone, all while at a location, and get broadcast quality, well as good as MP3 was at the time anyway.

At home I really liked Sound Forge as an easy editor, real simple to record and save. I don't have a clue if the Sound Forge has an Old Version you can freely get, or what the status of it is today.  Sound Forge was the boss editor if you want simple.

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SDR - Software Defined Radio / Re: Comparing the "KiwiSDR" and the "RaspberrySDR" software-defined radios

« on: January 07, 2021, 0811 UTC »

Good comparison, the new ones have the extra range compared to Kiwis.

I just have a noob question though, about Kiwi radios. I use different ones regularly, and notice that many have their own custom configurations, like some have buttons for SAM, others do not, the same with narrow and wide AM modes, others have DRM buttons.

What I wonder is if you as the operator have the choice about what buttons are given, and what modes are supported? For example, I can't see DRM being useful in North America, so if I ran a Kiwi, I'd want to replace it with something more useful.

Can that be done, or is it mostly controlled by the Kiwi company, and can they push updates over your config? How easy would it be to customize buttons, modes, by graphical interface or script at the command line?

Thanks in advance! Some of the simplest questions about running SDR don't seem to be in the guides.

19

The RF Workbench / Re: Watch out for those cheap components

« on: December 25, 2020, 0223 UTC »

Eww, that's gross. Maybe get away with it for experimenters, but let's hope they're not in millions of PCs like those capacitors in the capacitor plague years.

I see that, the font is like an older cement resistor would have, where it seems like most now are printed in dot matrix, where that's more like screened.

20

Part 15 AM and FM Station Operation / Re: If you had it all to do over again...

« on: December 25, 2020, 0206 UTC »

Tybee: Oh God, Mr. Fry, I wouldn't listen to anything he says in his articles, I think he's an agent who has set out to tear down part-15, not build it up!

I had a run in with Fry at a popular kit company's Help forum a number of years ago when he insisted that a station operated in the way people were discussing was not compliant with the rules, with field strength diagrams to prove that, produced by professional antenna modeling software. It got everyone upset. It happened more than a few times there from what I heard from others.

I got into it personally when I thought my station would be fine, installed with the ground wire like others had, and things heated up, because I was prepared to spend money to put a station on, and was holding my ground that it was okay, when he said the FCC might have another opinion, which I took to be a threat, and l looked up his info, thinking to visit his home and challenge him to a duel.

More research and I found out he was actually a solid engineer who had made contributions to radio engineering papers, and had done lots of work for the betterment of broadcasting.

As to why he would work hard to demotivate would be small broadcasters with absolute adherence to the rules, taking all the fun out of it, I have no clue. Are you really an esteemed engineer reduced to doing this, that's pathetic! I chilled then, realizing he was the one with the problem. Why be remembered as a killjoy?

For something peaceful now, it sounds like you've done great work with Carrier Current ThaDood, any idea who was listening, and did you give out a number or other way to contact since it was a legit station? I also like the mram us antenna, that seems like it would be a good thing to try, and cost less than antennas you can buy, and it looks stronger too. I like the traffic box used for mounting, that's great.

21

Part 15 AM and FM Station Operation / Re: This Knight lit up a lot of potential broadcasters!

« on: December 25, 2020, 0125 UTC »

The Knight must have been out at exactly the right time, when rock & roll radio was hitting big and kids all wanted to be DJs, so it was perfect timing, just take the phono oscillator, which had been out for many years, and make it junior DJ friendly, with a mike and phono input, and make it put out some power, and that's a neighborhood radio station.

Another article I saw once was kids had their own home station, the teen age guy and his younger brother ran it, Dad might have helped to build it, and they had news reports every morning and local announcements. The signal reached down their block, and they had listeners tuned in. People remember it in that it was filmed for a news report that even ran on AFRTS I think.

22

Part 15 AM and FM Station Operation / Re: Talking House Transmitter - some spectrum plots

« on: December 25, 2020, 0110 UTC »

Great info guys. The Talking House almost seems like something to play with and not what a serious station would bother using, but maybe tweaking and having it  as a a backup would be a good thing.

It's good for learning's sake though, once in the last decade there was a tech forum about modifying a toy transmitter, it was called the Planet DJ, a gadget for preteens that broadcasted on 20 foot on one signal frequency, yet the guys submitted many modifications and schematics about how to hot rod the circuit for better range and power, they were really into trying to make the planet into a full radio station!

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Part 15 AM and FM Station Operation / Re: Radio Survivor - Social Distancing Sparks Interest in Part 15 Unlicensed Broadca

« on: December 25, 2020, 0058 UTC »

I wonder why that Carrier-Current isn't promoted more, when it seems like the transmitters with antennas attached have websites with slick advertising and testimonials, but no one is doing that for Carrier.

Lots of people, like those in apartments and places where the can't put up outdoor antennas could use something like Carrier-Current, and you could take it anywhere and plug it in, seems like it would fill a need there.

Now on the coupler/tuners you've posted, it looks like there are a lot of step switches for the impedance and capacitance, but could this be done like a regular antenna tuner, like something from MFJ with capacitors and roller inductors, has someone tried?

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Part 15 AM and FM Station Operation / Re: Audio-Sine Part 15 AM transmitters (history)

« on: December 25, 2020, 0041 UTC »

That is a great and fascinating history you have dug up tybee!! I've been reading up on everything about low power and part 15 transmitters for years, and read anything about those early uses, and if there was something printed, it would amount to just one sentence in a construction article for a transmitter or where to receive such stations, such as schools, drive in movies, a car wash, I can recall those.

I tried to tune in to 530 and 1610 stations going by those articles, and didn't hear a thing, and wondered if what they were saying was even real. Later I did manage to hear a few low power, and then HAR stations on trips.

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Part 15 AM and FM Station Operation / Re: You can roll your own

« on: December 25, 2020, 0030 UTC »

Could the Black Cat System Beacon transmitter be modulated with AM or FM? That might be an easy way to get something ready to go at the proper power level.

I like The Dood's. I wouldn't worry about those guys either, they don't own the band. Most of what I've heard at 13.56 is just a continuous noise level centered around the middle of the band, it sounds like a hash from so many transmitters.

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Part 15 AM and FM Station Operation / Re: If you had it all to do over again...

« on: December 25, 2020, 0024 UTC »

I'd think fewer would care on the AM side these days, compared to FM, where there are lots of turf battles happening, translators wanting to go on, LPFM asking for more power, and I believe that there are "windows" coming up for both LPFM and NCE stations over the next year, so the FM band is going to be chock full. Another side to that is with all the stations clogging the band, fewer may notice a small FM station in the noise of other stations.

AM is good when you have an area with few stations on that band. It's fun to put a station on to broadcast something to your old AM radios and hear when driving to the store, thrilling when you get it all done and get on the air.

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Part 15 AM and FM Station Operation / Re: WLCR-AM Carrier Current Lewisburg / White Sulphur Springs, West Virginia

« on: December 25, 2020, 0013 UTC »

Really good article! That's the kind of thing low power is good for. Have to think there are many stations like this from camps and schools back then that we may never hear about, they were just another camp project. The kids probably learned something though.

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Part 15 AM and FM Station Operation / Re: Radio Survivor - Social Distancing Sparks Interest in Part 15 Unlicensed Broadca

« on: September 30, 2020, 1834 UTC »

Carrier-Current sounds like a good idea too. I can see at a school how they would use special wiring, to reach all of the buildings through wires branching out to them; more planning would be needed in that case.

For something simple, like at a church through the light poles, could the transmitter just broadcast through a an AC plug in the wall and transmit Carrier-Current that way? That would be even easier, with no antennas to set up!

I think churchgoers are more likely to accept AM for voice modulation to hear their pastor's voice.

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Part 15 AM and FM Station Operation / Re: Walmart Parking lot movies using Part 15

« on: September 30, 2020, 1824 UTC »

Hi Tybee, if 300 feet is the maximum range that the Decade can reach, I could see a lower range for stereophonic sound, since car radios will blend the channels when the signal is weaker. For a movie, the audience would want the soundtrack to be in stereo.

For that reason I think AM might not be so good for movies, radio-restricted mono sound wouldn't be what the viewers expect. On the other side, I could see AM for a pastor's voice at a church, and preaching is commonly heard on AM stations. An AM transmitter like the Talking House can be used, and it's almost as easy as AM, the automatic tuner, just provide a mono feed.

Multiple transmitter FM shouldn't have the interference potential of AM with transmitters on the same frequency, due to FM's capture effect, but FM can still interfere when transmitters are equal strength, or signals are weak at the receive location, then they could intermodulate with each other and cause distortion.

Good questions, now I want to see a WalMart movie.

Bear

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Part 15 AM and FM Station Operation / Re: Radio Survivor - Social Distancing Sparks Interest in Part 15 Unlicensed Broadca

« on: September 30, 2020, 1709 UTC »

I've been hearing about this, seeing the videos in my feeds with churches and others using part 15, and thought it's good that radio is being used as a cheap and simple way to serve an audience.

Well, if that's true, picowatts, a little power goes a long way.