I considered the wifi route @ArtisianRadio. I have a good bit of experience with wifi and a big crate of unused wifi gear sitting in the basement.
Problem with wifi here is the density and proliferation of 2.4Ghz devices and thus interference. Interference is so bad here that our wifi setup often is unusable or knocked out by neighboring signals.
Unsure of the entire power consumption, but the wifi route will end up sucking a lot of power on both ends. For us, both ends will likely be off grid.
I need to be cognizant of power draw since expansion ideas and perhaps initial site lack grid power. To introduce grid power means $25/mo estimated minimum just for power. Years ago I wouldn't have minded, but today these small costs really add up quickly.
All that said, I am still tinkering with low power computers at/near transmitter for doing processing, storage, files, playing audio, etc. Depending on how that goes, might roll FM receiver in via USB channel. The FM receiver via USB would meet the low power need as well as compact receiver requirement.
Still very interested in other solutions though.
for the audio as mentioned in another thread. I suspect two twisted pairs of the cat5 are used for audio leaving other pairs for power or monitoring if you can break them out at the ends.
It can be fun to plan these things so keep us posted on what you come up with.
Neil
Well, the wifi receiver can be battery powered, so power consumption wouldn't be great.
However, I also thought of putting a low power computer at the transmitter site. Then you wouldn't need any audio transmission at all, since you could drive the transmitter directly with that computer (and control it via wifi, using a remote control program).
It just seems to me that it's complicating matters greatly to use two Part 15 transmission systems that could be operating on the edge (and inspected by the FCC) when you could easily eliminate one of them by some other method (I know that wifi is also Part 15, but it is also so common and widespread that the FCC doesn't give it much thought).
Artisan brings up a very valid point about using two part 15 systems when one would be better, i.e., FM to AM.
I worry about my FM, which is only being used as an STL (Studio Transmitter Link) attracting undue attention. There would be greater peace of mind if it could be turned off, given the fact that FM seems to be of more concern to the FCC than other bands.
The WiFi idea is worth exploring.
Truly, the double Part 15 emitters are double the compliance concern.
The non compliant issue Whole House FM transmitter was a cheap buy and worth exploring. At worst, I will tinker with low power FM otherwise. Other transmitter I have used for FM in the past is way over limits for output 🙁
Coupling the audio over CAT5E and newer cable is possible. Gets tricky quick though. Basically to do this right inside of one cable need to pipe data plus 12v power plus audio.
Data = network for the LAN connection
12V power = to power devices (computer, FM receiver, etc. including the transmitter)
Audio = stereo feed
The balun I posted in another thread does just the audio over CAT5e. Unsure how many wires they are using to accomplish this.
Cat5e and lower end up with 4 wires being unused. So if that balun uses a pair leave one pair left for the power. So it is doable with caveat that network will be limited to 100Mbps, which is more than adequate.
Eliminating the audio balun would reduce complexity. Working with Cat5 cable like this is a pain (thin and have short area to make splices).
Audio could be pushed via total digital encoding (via computer) as data and decoded on other end. Not a ton of low power and compact options to accomplish this. Easiest way is likely an ARM based low power computer like I've mentioned on other threads. Basic a Barix imitator.
This all gets mighty pricey and complicated. Breakage probability is quite high.
I am going to lay out the options and pricing and do a mock work through with variables here and weight things to see what best options actually should be.
Whatever I end up doing will certainly be sharing here for others to learn and for new folks who find this hobby in the future.
Problem with those two being used as a link to a transmitter is the inherent delay encountered and packet loss/net congestion.
RFB
I wanted to try this but never got around to it..
I have a set of amplified speakers that runs on 12 v.d.c. with an fm receiver in each one. They operate in the 800 mhz. region. There's a transmitter that accepts a 3.5 mm input that tramsmits stereo and each speaker receives a seperate channel. (L&R) The transmitter operates on 12 v.d.c. It accepts line level..
Basically, both speakers have a battery holder in the bottom that holds 8-"D" cells that houses an audio amp and the receiver.(and speakers, of course) The transmitter is connected to an audio source and runs on a wall wart @ 12 v.d.c. It is intended to be used as a wireless speaker system to place speakers in a room without the need to run wires. Each speaker can be operated with a wall wart also..
I had them ~30' apart and they worked rather well. I pondered the thought of adding an antenna to both receiver(s) and the transmitter to extend the range using a few of these..
http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=LPY41
I was going to gut them out and work with the receivers/amps and convert the level(s) for an input to an SStran. Add an antenna to the transmitter and see what happens.. (I think I have 2 sets somewhere around here..) 😉
The delay with wifi and data conversion can be fairly low. Depends on signal strength and interference.
I use to have a 5.8Ghz internet connection that ran from a valley where I lived to the other end of the valley (about 1.25 miles). From there the signal beamed over a few mountains to another site about 2.5 miles away then from there it headed way north some 15+ miles.
That trip from my computer to the device on the network some 18+ miles away took normally 5 milliseconds. The connection was rock solid even in bad weather. It was Trango brand equipment for those that are curious and all non-licensed.
Now, none of that involved conversion of audio and conversion from data back to audio on the other end.
I'd expect that at those distances is doable even with audio conversion on both ends in total of under 20ms.
I plan on doing some local LAN and wifi tests with various configurations to test non scientifically the latency. Basically by housing receivers in one room and broadcast (AM and FM) as well as wifi outdoors. Basically play audio out like real setup and catch the signal in same room and play it back next to the actual source playing.
The trick for any data wireless to work very well is direct line of sight - meaning both end devices visibly are clear of obstructions.
There are of course some other delays introduced into a solution like this, namely caching of the audio stream. This is done to buffer before play to avoid skips and misses. To do that, the stream does run behind real time by 2-10 seconds typically. The 10 second buffer is acceptable I think as the FCC has such regulations to delay signals to avoid profanity ending up live on public airwaves.
Might be a good choice, and save on power consumption by removing the audio power amplifier, which would not be needed anyway.
Watch out now....someone will declare it out of compliance if you add an antenna to that transmitter!! 😮
RFB
"That trip from my computer to the device on the network some 18+ miles away took normally 5 milliseconds."
Ask any DJ who preferences to monitor the off air signal in their headphones while talking, how much even 5 milliseconds is quite annoying!
But at 2.5 miles or more...who's gonna monitor the off air signal anyway as by the time that signal reaches back to the studio..it will be so noisy the operator will switch to program line monitoring!
RFB
There really is no packet loss/net congestion if you're using wifi over your own intranet (i.e., your own network).
There is delay, but who cares? When you use a transmitter and then stream, the stream is usually several seconds behind the transmitter. With the above method, the stream and the transmitter are essentially brought back together, timewise. But since you're more than likely only going to be listening to one or the other, again, who cares?
I can understand the annoyance of doing a brodcast and what is in headset is different or lagged from live time.
Unsure what folks do. I'd expect the live talent to be crafting the show and not listening to the broadcast while the board operator listens to the produced feed, either live, after the board or from the transmitter.
I intend on listening live time to nothing. So the delay/lag won't really bother me.
Probably going to try the balun as well as the FM-to-AM combo to see what performs and where the problems are with each.
If I decide to put my transmitter to my back lot, there isn't electric and can't run wires from here to there. So FM transmitter or wifi or other audio bridge over wireless are pretty much my only options absent monthly charges.
It's interesting comparing notes with the Part15 amateurs versus the more seasoned broadcast pros.
"There really is no packet loss/net congestion if you're using wifi over your own intranet (i.e., your own network)."
Sure..out in the wilderness where there isn't any other wi-fi going on, or others around to hack into that phantom private network.
"There is delay, but who cares?"
Umm...the DJ trying to talk who want's to hear the over the air signal than the program line signal.
Audience won't know any different but I wasn't referring to the audience I don't think...was I? Let me go back and re-read my post to make sure.
RFB
" I'd expect the live talent to be crafting the show and not listening to the broadcast while the board operator listens to the produced feed, either live, after the board or from the transmitter."
Your describing either a large talk radio operation or how things used to be done way back in the very early days of broadcasting..not so these days. Most "talent" who spin music would prefer to control their mix while speaking. A second board operator can't read the talent's mind and know when to "ride" the controls during the speaking.
"I intend on listening live time to nothing. So the delay/lag won't really bother me."
One person operations like most of us are..it wont' really matter. As I also pointed out, the audience won't know the difference either.
There are a variety of options available to you, in all of the threads started recently which have been discussed many times before and always led to what's currently being re-hashed again.
As I suggested to another, might try the search box and find plenty of other suggestions including repetitive suggestions spanning several years.
Either way you go, there are interesting challenges and unique solutions ahead. Trick is to pick one and go with it and see if it will work or not.
With the amount of information stored in the thread archives..and multiple times the information is in there, there is bound to be one that will work for you in your unique situation.
I never was too fancy on co-located equipment away from my sight or reach. Too much liability issues and concern of vandalism. I don't even like the idea of having the transmitter itself sitting in a box outside on my own property. I prefer it to be inside the same room where the studio gear is. That's just my preference that works for me.
As to the wireless linking to a transmitter located at some distance where you can't run any wires, that will have to be set up so the transmitter and receiver gear are powered either by juice from that remote location, or solar powered charging batteries at the same time, which can turn the venture into quite an expensive venture too. If the idea is to make expense as low as possible...your choices become limited at that point and the nice ideas tossed out here and in the abundant repetitive thread archive becomes pointless and the obvious simple solutions will become more relevant.
RFB
There are some good points being made here about using wifi and delays, particularly if you are listening to your own audio. My radio station is totally automated, so that isn't a factor. And there ARE delays with wifi, even with your own intranet (wilderness or otherwise).
But I certainly know that if I were in the U.S., I'd think twice about using Part 15 FM to feed a Part 15 AM station - if you're more than 100 feet away from the FM transmitter, I would think that a legal FM signal would be sufficiently weak that interference would become a factor. And if you're less, then you might as well run audio cable to feed the AM transmitter.
Plus, the FCC is certainly more vigilant with Part 15 FM. You might have a perfectly legal AM installation, but have issues because of the FM feed. And there are far fewer certified FM transmitters. You tend to have the inexpensive ones that have far less range (such as the C Crane or Scosche) and the very expensive ones such as Decade, which have better range and sound, but still less than 200 feet to a portable receiver. The others - well, I suspect that there are reasons why a lot of them aren't certified, including out of band emissions and noise, field strength greater than the maximum allowed, etc. Using a certified transmitter is far more important on FM than AM, as the limits are so much stricter, and that FCC vigilance.