Anyone know of a stereo audio (with composite video is ok but not needed) wireless system that is high performance and good range?
Even a chipset or some hong kong modules?
I see Linx has a module with good specs that will do audio but just one channel.
Don't want wireless digital -- ton of those.
And yes, know about the radio shack and terk systems but they are junk.
ROHM has a family of analog ICs for stereo to FM convertors. Making your own transmitter using one of these is very straightforward. Indeed, many factory made FM convertors are poorly done.
Vladimir Vassilevsky DSP and Mixed Signal Design Consultant
"mkr5000" Anyone know of a stereo audio (with composite video is ok but not needed)
** So you are asking for a two channel, FM audio system on VHF or UHF - with good range and high quality.In the world of professional audio, that would mean using a pair of UHF radio mic systems.
But in 99% of such cases, it is far cheaper and better to use a pair of cables.
What is SO special about YOUR idea that makes that impossible?
.... Phil
Which reminds me... it's patio season here in Arizona... anything like a wireless link for VIDEO, so I can watch cable TV out in the middle of my backyard ?:-) ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
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I love to cook with wine. Sometimes I even put it in the food.
Requiring video will require higher (often illegal power levels) and/or reducing the range considerably.
Some high quality wireless (FM) headphones might be a good starting point (low noise electronics at both ends). Of course, the transmitter antenna should be placed on a good place or possibly using a leaky feeder around the area to be covered.
If the reception area contains a lot of reflecting surfaces (walls), the FM signal can suffer badly due to multipath propagation nulls. A diversity receiver system should help.
On a sunny day (Tue, 1 Nov 2011 13:49:58 -0700 (PDT)) it happened mkr5000 wrote in :
wireless system that is high performance and good
Just use FM:
Those video senders work reasonably well with composite video. Or you could make your own link using two AV modules like these.
a y
For RadioModules: Rx =A317.50 (Inc VAT =A321.00) Tx =A310.48 (Inc VAT =A312.58)
Youse guys need a NEW goverment.!!!
Talk about STOPPING business transactions.
Ebay is full of them.... Videosender, 2.4G /5.8G
Anyone know of a stereo audio (with composite video is ok but not needed) wireless system that is high performance and good range?
Even a chipset or some hong kong modules?
I see Linx has a module with good specs that will do audio but just one channel.
Don't want wireless digital -- ton of those.
And yes, know about the radio shack and terk systems but they are junk.
---------------------
Do you realize that wireless analog is very dirty and if this is for a "hi fi" type of application it will be unacceptable by most? Digital audio over wireless can be represented exactly, corrected for errors, and has a higher margin for interference.
I use IR earphones in my office... Sony TMR-IF330R. ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Yeah, there are loads of 'em. May need to be line of sight or close - or need repeaters.
They're really meant for ceiling-mounting projectors.
-- Les Cargill
Analog voice transmission using FM can be quite good if the propagation path is clean (no multipath) and you have sufficient power and bandwidth to burn :-).
Using the parameters for monophonic FM broadcasts (15 kHz audio bandwidth +/- 75 kHz deviation) can give quite results. The modulation index is larger than 5 on any audio frequency, thus a quite significant "FM gain" can be obtained. If you have, say 50 dB CNR prior to the FM detector, then the audio SNR after the detector is very good.
Unfortunately in the real world, this is quite hard to achieve. First of all, you need two about 300 kHz wide noise free channels to carry the stereo signal. Where do you get such spectrum these days ?
Getting 50 dB CNR is hard, either you need a huge amount of transmitter power (which is typically limited by local regulations) or the range will be very short.
The OP might be scared by some badly implemented very lossy wireless links.
Assume that we need to transfer uncompressed PCM at 2 channels x 44.1 kHz x 16 bits = 1.4 Mbit/s net and with framing and _strong_ ECC, about 3 Mbit/s gross rate is needed.
Using DSSS in the 2.4 GHz band with 10-100 times chip rates would give quite good resistance to multipath in a 30-300 MHz bandwidth with quite reasonable power levels (or quite long distances).
Trying to get 6 dB more audio SNR will cost you a four time (400 %) increase in power requirement in an analog system, while in a digital system increasing the audio SNR by 6 dB (say from 15 to 16 bits) will only require a 7 % power increase.
"Don Fuckwit Mack"
** Never seen any of the better VHF and UHF radio mics sold for professional and music use in the last 30 years ??Mono, wide band FM is inherently very high quality and with the use of companding and twin diversity receivers the recovered audio signal is rock steady indoors or outdoors.
** Shame they need too much RF bandwidth to be practical at the usual VHF or UHF mic frequencies.... Phil
Even the old broadcast AM channels can be of surprisingly good quality. I have a TRF receiver "High-Fidelity Tuner" designed by J. W. Miller which I built over fifty years ago. It's surprising how good the reception from a properly maintained AM station can be.
(Yeah, I know the high frequencies are limited to the 10KC AM channel, but a 10KC cut off is not too bad!)
-- Virg Wall, P.E. (One time "Broadcast Engineer".)
The problem with AM for high audio SNR (say over 50 dB), the signal power has to be at least 50 dB stronger than noise or interference. Increasing the audio SNR will either require 100 times more transmitter power or reducing the range to 1/10th in free space conditions.
High modulation index FM will have a significant "FM gain" which adds to the CNR, thus keeping the power levels more reasonable.
In order to get very high audio SNR, the only realistic solution is to use some digital transmission system, since transmitter power needs to be increased only a few percents for each added bit, but the audio SNR improves by 6 dB for each bit added.
If you have a 5 kHz audio tone, it will produce sidebands at +/-5 kHz, occupying the whole 10 kHz channel ?
Or are you referring to some conventions, in which transmitters in a specific area are spaced at a 20 kHz, thus allowing sidebands at +/-10 kHz. In some other area the channels in between are used ? In such a system 10 kHz audio bandwidth would indeed be usable very close to local transmitters.
Receivers between areas with different frequency grids will suffer from sideband overlap and would have to cut the audio bandwidth well below 5 kHz to avoid splatter from the unwanted station 10 kHz away.
To get 10 kHz audio through a 10 kHz channel, you would have to use SSB.
** HUH ??
AM broadcast "channels" are not 10kHz wide.
Local AM transmitters are 100kHz apart in most places.
** Wot place are you from - wanker ?Your silly handle says it is Australia where AM transmitter are widely spaced.
Where on earth are there are * 110 * AM transmitters in the same locale ??
( 1650 - 550 = 1100 / 10 = 110 )
... Phil
In the US 10KHz spacing is used from 520KHz to 1610KHz.
On a sunny day (Thu, 3 Nov 2011 22:18:28 +1100) it happened "Phil Allison" wrote in :
Maybe you have never done it, but if you listen late at night on the AM band, then every kHz is in use. Some signals are from far away and extremely strong. Nothing to do with 'local'. Digital AM tuners use a 10kHz raster IIRC.
"Jan Panteltje"
** Fuck off - wog imbecile.ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.