Noise on Wireless Transmitter
 

Hi,

I'm an electronics neophyte, but went out and bought a 2.4 Ghz wireless
audio/video transmitter/receiver set from Radio Shack. Trouble is, I can
hear the music I'm transmitting from my PC to the sound system, but there's
a steady ticking noise. I'm wondering if I'm supposed to put a filter on the
device, or is the one I bought just a cheapo?

Cheers

Noise on Wireless Transmitter
 

How are you powering the transmitter?

John Davis wrote:
Hi,

I'm an electronics neophyte, but went out and bought a 2.4 Ghz wireless
audio/video transmitter/receiver set from Radio Shack. Trouble is, I can
hear the music I'm transmitting from my PC to the sound system, but there's
a steady ticking noise. I'm wondering if I'm supposed to put a filter on the
device, or is the one I bought just a cheapo?

Cheers

Noise on Wireless Transmitter
 

John Davis wrote:
Hi,

I'm an electronics neophyte, but went out and bought a 2.4 Ghz wireless
audio/video transmitter/receiver set from Radio Shack. Trouble is, I can
hear the music I'm transmitting from my PC to the sound system, but there's
a steady ticking noise. I'm wondering if I'm supposed to put a filter on the
device, or is the one I bought just a cheapo?

Cheers


There's about a million things in that 2.4 gHz band. Microwave ovens
are the worst offenders, but they are intermittant, unless you live near
a restaurant...telephones, wifi...all sorts of things.

The best you can hope for is to carefully orient the antennas for the
best reception. There are highly directional antennas available--both
pre-built and plans...several use a Pringle's potato chip can as a
waveguide--but these require some soldering ability to implement.

With the above, however, you probably 'could' get a narrow enough
coverage angle to mechanically filter out any interference.

Google "homebrew 2.4 gHz antennas" or "pringles can antenna" for links.

jak

Noise on Wireless Transmitter
 

"jakdedert" wrote in message ...
Date: Fri, 14 Oct 2005 12:20:16 -0500

John Davis wrote:
Hi,

I'm an electronics neophyte, but went out and bought a 2.4 Ghz wireless
audio/video transmitter/receiver set from Radio Shack. Trouble is, I can
hear the music I'm transmitting from my PC to the sound system, but there's
a steady ticking noise. I'm wondering if I'm supposed to put a filter on the
device, or is the one I bought just a cheapo?

Cheers


There's about a million things in that 2.4 gHz band. Microwave ovens
are the worst offenders, but they are intermittant, unless you live near
a restaurant...telephones, wifi...all sorts of things.

The best you can hope for is to carefully orient the antennas for the
best reception. There are highly directional antennas available--both
pre-built and plans...several use a Pringle's potato chip can as a
waveguide--but these require some soldering ability to implement.

With the above, however, you probably 'could' get a narrow enough
coverage angle to mechanically filter out any interference.

Google "homebrew 2.4 gHz antennas" or "pringles can antenna" for links.

jak

I get the same problem (ticking sound) between my cordless Siemens
Gigiset 2430 2.4G and my wireless 2.4 video/audio setup. And the
video/audio transmitter limits the range of my WiFi setup (also
using 2.4G) and sometimes WiFi doesn't work at all.

Turn off the video/audio transmitter, the other two 2.4G gets along
just fine. I have another really cheap 2.4G cordless phone and it
knocks out the WiFi really badly. Good thing I stuck it in the
closet for now. Although the Siemens works with the WiFi really
nicely. As the phone can be right next to the WiFi antenna and both
continues just fine.

The 2.4G standard is supposed to be really great for multiple
devices using these frequencies. As it is supposed to be nice to
other devices. As they seek a clear channel and then do there stuff.
And they are supposed to switch channels if the one its using has
some outside interference.

Well this works in many cases, but others it doesn't so well. I
guess one could have too many devices for one. Also I don't believe
those video/audio transmitters ever follow the rules anyway. At
least the RCA one that I have (WVS150) doesn't. As it will only
transmit on 4 available channels and you must select one of them
manually.

The interference between the video/audio receiver and the cordless
phone might be do to the Siemens is supposed to change (hop) 100
channels per second. This is supposed to be a security feature. Thus
the ticking sound.

I bet as jak already mentioned that some other device is causing
your problem. If not you, then someone or something nearby.


__________________________________________________
Bill (using a Toshiba 2595XDVD under Windows 2000)
-- written and edited within WordStar 5.0

Noise on Wireless Transmitter
 

There are several different 2.4Ghz RF standards and they do not all play
well together (nice to other devices in your words). For example, some of
these used Frequency Hopping Spread Spectrum (FHSS) where the carrier
channel changes at pre-defined intervals without any regard to whatever
other devices are operating in the same spectrum. In addition, there are
also things like RF baby monitors, cordless phones, and microwave ovens as
you already pointed out that also transmit without regard to others using
the frequencies.

2.4Ghz WiFi (802.11b and 802.11g) fits your description though in that it is
a listen before transmit technology so tries not to clobber other WiFi
devices sharing the same spectrum. Although it may be the case for SOME
cordless phones or monitors, WiFi APs will not switch channels though
automatically, despite how much interference they encounter.

Bob

"BillW50" wrote in message
...
The 2.4G standard is supposed to be really great for multiple
devices using these frequencies. As it is supposed to be nice to
other devices. As they seek a clear channel and then do there stuff.
And they are supposed to switch channels if the one its using has
some outside interference.

Noise on Wireless Transmitter
 

Hi Bob... Thank you very much for the clarification. Say isn't there
also a DSS standard (vs. FHSS) that does basically the same thing as
well? Although I believe I only had seen it on 900MHZ devices. Then
again, is what I am calling DSS the same thing as Direct Sequence
Spread Spectrum (DSSS) used on most modern WiFi at 2.4GHZ?

__________________________________________________
Bill (using a Toshiba 2595XDVD under Windows 2000)
-- written and edited within WordStar 5.0


"Bob Shuman" wrote in message ...
Date: Fri, 14 Oct 2005 13:21:05 -0500

There are several different 2.4Ghz RF standards and they do not all play
well together (nice to other devices in your words). For example, some of
these used Frequency Hopping Spread Spectrum (FHSS) where the carrier
channel changes at pre-defined intervals without any regard to whatever
other devices are operating in the same spectrum. In addition, there are
also things like RF baby monitors, cordless phones, and microwave ovens as
you already pointed out that also transmit without regard to others using
the frequencies.

2.4Ghz WiFi (802.11b and 802.11g) fits your description though in that it is
a listen before transmit technology so tries not to clobber other WiFi
devices sharing the same spectrum. Although it may be the case for SOME
cordless phones or monitors, WiFi APs will not switch channels though
automatically, despite how much interference they encounter.

Bob