Why no 2.4Ghz Digital Wireless Systems? (Battery Powered)

[frantick]

So companies like Line6 have come out with 2.4Ghz wireless systems, but their intended use is stage so all of their receivers are 120v wall power. Why haven't any ENG systems come out, like the Sennheiser G3 systems that use the 2.4Ghz band? Does the receiver draw too much amperage to run off battery power? How about lithium or lith-poly batteries?

I would just think this would be a hot seller, or is there a reason?

-cp

 

[olgak]

In short -Short range ;-)
While you go up with fq carrier ,you will need more power to increase the range

 

[frantick]

Ah, that makes sense. Thanks, -cp

 

[John Willett]

So companies like Line6 have come out with 2.4Ghz wireless systems, but their intended use is stage so all of their receivers are 120v wall power. Why haven't any ENG systems come out, like the Sennheiser G3 systems that use the 2.4Ghz band? Does the receiver draw too much amperage to run off battery power? How about lithium or lith-poly batteries?

I would just think this would be a hot seller, or is there a reason?

Because 2.4GHz is a horrible frequency to use.

Range is very short - you are strapping a microwave transmitter to someone's body (I would certainly not want to have such a transmitter on my body) - the band is full of low power devices and the chances of interference are very high.

I think the range is about 30 feet, rather than 300 feet plus for a normal radiomic.

It really is unsuitable for professional audio devices.

 

[j1clark@ucsd.edu]

So companies like Line6 have come out with 2.4Ghz wireless systems, but their intended use is stage so all of their receivers are 120v wall power. Why haven't any ENG systems come out, like the Sennheiser G3 systems that use the 2.4Ghz band? Does the receiver draw too much amperage to run off battery power? How about lithium or lith-poly batteries?

I would just think this would be a hot seller, or is there a reason?

-cp

The 2.4 GHz band is a 'free for all', which means there are many potential and existent interferers. BlueTooth, cordless phones, microwaves, etc. All can and will interfer at the least opportunity. The UHF band is 'safer', unless the dreaded White Space Devils come stalking... but I believe the FCC has allocated a set of UHF band channels for wireless mics, a location registry, and so, the WSD should be put somewhat at bay...

Given the way 2.4 GHz is used, it really is 'designed' for an an environment were if the packet of data makes it, all is fine and well, and if it doesn't... well retransmit, or some form of forward error correcting, is required. VOIP applications that use 802.11 type devices, are so reduced in bandwidth for the voice traffic that one can think about adding FEC to make the transport more reliable...

I'm off this week to test some 2.4 GHz stuff in a vehicle that uses the 2.4 as an internal to the vehicle communications path... saves on wiring up things... but the customer is complaining that their 'video' is 'choppy'... duh...

 

[Captain Pierce]

Because 2.4GHz is a horrible frequency to use.

Range is very short - you are strapping a microwave transmitter to someone's body (I would certainly not want to have such a transmitter on my body) - the band is full of low power devices and the chances of interference are very high.

I think the range is about 30 feet, rather than 300 feet plus for a normal radiomic.

It really is unsuitable for professional audio devices.

The 2.4GHz band is home to a wide range of devices, with widely varying ranges--but many have a range well over 30 feet. And I have yet to see any wireless mic, in any band, that lives up to the manufacturer's claim of 300 feet.

Furthermore, if a 2.4GHz transmitter is inherently a microwave, then how the hell is it so widely used? Are you telling me that every 2.4GHz cordless phone is a microwave transmitter? That every Bluetooth cell phone headset is a microwave transmitter? That every Wi-Fi router is... OK, I think you get my point.

As it happens, my company uses 2.4GHz wireless mic systems manufactured by Sabine. These systems are far from perfect, but I can tell you from personal experience that their range is at least 150 feet, because I use them in a room that's 150 feet across, and the transmitters are up in the front and the receivers are in the back. And I did it two years with only the antennas that came with the system, not any kind of larger one (although I did finally talk my boss into buying better antennas ). Oh, and there's Wi-Fi in this facility, too, but I've never had an interference problem. We've had Shure UHF systems that wouldn't reliably work at 100 feet.

Now, the thing about these systems is that they're expensive, and they're still using a full-rack-width receiver where just about everybody else has gone to half-rack. So it may be that the cost to miniaturize the components to an ENG form factor isn't worth it. ENG seems to be a small chunk of the wireless market, one that a lot of manufacturers just don't bother with. (As much wireless as Shure does, for example, they've never done ENG, or at least not recently.) And the manufacturers that do concentrate on the ENG market are still making all their systems (not just the ENG ones) in the traditional UHF bands. With all the turmoil in UHF lately, though, who knows what we might see down the road...

 

[olgak]

Because 2.4GHz is a horrible frequency to use.

Range is very short - you are strapping a microwave transmitter to someone's body (I would certainly not want to have such a transmitter on my body) - the band is full of low power devices and the chances of interference are very high.

I think the range is about 30 feet, rather than 300 feet plus for a normal radiomic.

It really is unsuitable for professional audio devices.

sorry to disappoint you , there is nothing wrong to use any fq but as i pointed ,making transmission on hi fq you will need more power to transmit .more power - shorter the battery life , shorter the battery life - bigger battery ,bigger battery -bigger the device. bigger device -another solution .
how many users you have on that band its not an issue for if it works or not , if they will make 2.3 or 2.5 ghhz units there will be no any
the UHF system could be in the range of closest digitall tv station and you will get 2 feet of range .

http://www.sabine.com/sabine-professional-audio/True-Mobility-SWM7000.html

zaxcom also have "professional stuff " which works on 2.4 ( ifb )
so dear - skip on what is is not your main subject