Found an interesting product for long audio runs for transmitters.
This solution uses 3.5mm standard output audio plug like you find on computer soundcards and portable audio players. That plug connects to an ethernet port. You run cheap and readily available CAT5, CAT5e, etc. cable from there to remote site. On other end the cable terminates into matching end balun and outputs to another 3.5mm port you can plug into most transmitters Part15'ers use.
Some features:
* No signal loss and no degradation after the long cable run.
Audio Input Connector: 3.5mm Stereo mini x 1
Audio Out Connector: 3.5mm Stereo mini x 1
RJ45 Connector: 2 ( 1 for transmitter and 1 for receiver unit)
Max Transmission Distance: 250 feet
Bandwidth: 10 Hz to 50 kHz +/-3 dB
Operating Temperature: -10C ~ +50C
Environment Humidity: 0 ~ 95%
Wire Type: UTP Category 5, 5e, or 6
Operating Temperature: -10°C to 70°C
Price: $9 + shipping.
What do other folks think of this product? Sound reasonable?
Sounds like a good way to achieve a long run an I assume that these use transformers. I didn't see any mention of isolation but if so then this would avoid ground loops.
I do wonder though how they provide "absolutely no signal loss" when the specs. indicate a frequency range with dB mentioned. Sales hype no doubt.
Neil
Useful for the Talking House and similar transmitters that use mini stereo plugs.
The ProCaster and Rangemaster already provide audio interfaces.
And if you use outboard signal processing, then you'll generally have to wire up the CAT 5 directly (many use screw type balanced outputs, i.e. the Inovonics 222 and others).
Mini-plugs and even so-called "phone plugs" are very poor in serious audio work, especially in an outdoor environment with extremes of humidity and temperature.
They lose electrical contact and need to be cleaned and re-plugged at periodic intervals.
Gold plated ones are much better, but better still are screw terminals, checked seasonally for firmness.
Good information 🙂
I am weary of consumer grade connectors, but tons of readily available pieces and parts use such. The plugs in my scenario would be indoors on one end at the mixer rack. The other end would be inside a piece of PVC pipe likely. To avoid issues connector outdoor could/should perhaps be sealed and wrapped in high conductivity gel? I self wrap lots of electric splices with a liquid tape wrap. The stuff ends up like rubber when dried. Would likely do the same if oxidation appears too quickly.
Looking for subtle quality. Not high end studio level, but not horrible old fashioned washed sound either. End output is AM mono, so losses are fine and tolerable.
These baluns are not powered in any way. Presume they sip power from the input source. Does that work? Likely, but probably not as good as they want us to believe.
There are other baluns from other sellers that are similar but include power on one end and have much longer range -- 1000 ft as opposed to 250. Thought I saw some claiming 5000 feet.
Regardless of balanced or un-balanced, balun or no balun, the longer the line the more resistance in that line to the signal applied, even more so when using a balun as the balun itself introduces some resistance..on both ends.
5000 feet is to the extreme. CAT5 cable isn't quite geared for running signals at such great lengths..even for sending network protocols.
Heck telco companies have to put in line boosters along their cables every so often, certainly before 5000 feet! I have seen them place these line boosters at every 100 feet especially for lines carrying digital signals.
The powered baluns will incorporate these booster amplifiers to allow for distances greater than 100 or so feet.
RFB
FYI: Cat5 and newer are limited normally to 300ft for network runs.
The CAT5 baluns continue to be interesting. Hasn't been but a few mentions of such a solution on here. Unsure if anyone has done this balun style audio distribution with Part15.
"FYI: Cat5 and newer are limited normally to 300ft for network runs."
Already knew this..Assoc. degree in IT networking JFYI. 🙂
RFB
"The CAT5 baluns continue to be interesting. Hasn't been but a few mentions of such a solution on here. Unsure if anyone has done this balun style audio distribution with Part15."
Probably because MOST Part 15 operators around here are running a simple wire off the back of a transmitter kit primarily feeding audio to that good ol antique radio in the other room..very little need to run 5000 feet of CAT 5 audio cabling!
But for your proposed setup, why not give it a whirl and see how goes? Any additional info on the real world experimentation is always a good thing!
RFB
I operated a Rangemaster over 300' from the shack to the xmtr using Cat-5. I picked a pair for the audio and doubled up a pair for power. I ran speaker level (~1/2 watt) down the selected pair from a small battery powered radio (mono) getting it's content from an FM xmtr that I was yardcasting with near the hut. Had a 1:1 600 ohm transformer at the xmtr end for a load. Adjusted the level via the volume control on the FM radio..
Had a 12-24 volt converter at the shack and powered the Rangemaster through the doubled pair. Boosted the voltage to cover the losses in the wire at that distance. Still had near 20 volts at the xmtr..
Worked fine.. Last long time!!
The CAT 5 100 meter (~300 feet) limit refers to operation of 100 MBit ethernet connections. The limit is imposed simply to say the connection exceeding that length does not meet TIA 568 spec for error free data communication.
All of the CAT type cables have the same distance limit they just run at different data rates.
You will be running base band audio so the 100 meter limit would be meaningless. However, there would be copper loss as RFB pointed out due to the DC resistance of the wire.
The balun may step up the signal voltage into the cable like a transformer. This would reduce the copper loss depending on how much the signal voltage is raised (higher voltage, lower current.) On the receiving end the balun would step the signal voltage back down. This may be how they advertise such extraordinary transmission distances.
Killer proof of concept 12vman.
Sounds like you've already done what I was awkwardly dancing around conceptually.
So did I read right? You produced your program/original source inside building then outside to a FM low power xmitter. Then that went a distance to a radio that picked up the FM signal and from there you cabled CAT5 and ran that a while to meet up with your Rangemaster to broadcast the AM signal?
How did you keep that FM radio always running and charged?
Use a regular old length of TV coax to carry the FM signal. Inject the DC voltage through DC couplers/isolators on the ends and no worries about fading FM signal out to the TX.
RFB
Used a DataKit FM xmtr at the shack on 91.9 for local coverage. It was connected to the house battery direct. Used an ElCheepo FM mono analog pocket radio for the audio send to the Rangemaster. It operated with a 9 volt battery but I used a LM7809 from the house battery to keep it alive. (Remember my place is totally 12 v.d.c.)
The 1:1 600 ohm transformer at the Rangemaster provided 2 functions. A load on the audio line and isolation to avoid any chance of a ground loop..
The reason I did this was to get the AM outside of the woods. My shack is surrounded with trees and my range suked! I wasn't concerned too much about the FM range. I just wanted to be able to use it at my porch and around the yard. Drinkin' beer around a fire with my home made solar powered boom box is always a good time, listenin' to what I wanna hear..