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Fw: Local Noise on 2.4 GHZ



I have heard several unconfirmed reports of high power (ERP) operation of
2.4 GHz and 900 mHz license free links in the mid Florida area.
These have consisted of higher gain antennas to increase range
when the maximum ERP will obviously be exceeded and the use
of external power amplifiers. These operations have been reported
to have been used on video links and spread spectrum control links.
I also have unconfirmed reports of higher that allowed ERP operation
on the 902 to 928 MHz band. It is easy to accomplish since the
power amplifiers and antennas are readily available.

I think if any licensed amateur who experiences interference from
these devices should do everything he or she can to assure that the
interfering devices are inspected to assure proper and legal operation.
If you are experiencing interference it seems likely to me that the device
is probably putting out excessive power or has spurious emissions.
This may be due to unauthorized power amplifiers that are not
properly filtered and are not FCC type accepted for the application.

73

Tony
W4TAS




-----Original Message-----
From: joseph Murray <k0vty@juno.com>
To: n8fgv@amsat.org <n8fgv@amsat.org>; amsat-bb@amsat.org
<amsat-bb@amsat.org>
Date: Wednesday, December 26, 2001 5:20 PM
Subject: Re: [amsat-bb] Local Noise on 2.4 GHZ


>Hi
>
>The ARRL reported 15 Feb 2001 that the FCC stepped into a interference
>problem between a ISP on 2.4 gHz and a Ham using 2.4 gHz ATV down Dallas
>TX way .
>Wide band versus wide band it would appear.    The final result of the
>action is not known.
>The FCC asked the ISP what it intended to do about the interference .
>
>I have a personal interest because :
>
>I also use a 2.4 gHz ISP service .    Too which is added a Radio shack
>2.4 gHz Video / audio system to enable two TV's on my DirecTV satellite
>link.   Additionally I use a 418 mHz extention to the DirecTV remote
>control so I can control the second TV in another room.   That device is
>also Radio Shack.
>As far as interference ,  When I transmit with the PC it does show up as
>burst lines across the TV screen and you can hear it popping in the audio
>on the TV .    The TV is next ( 7 ft ) to the computer .  This
>interference is so short of duration that I don't mind it normally.
>If I am down loading a large file the duration increases.    Santa  (
>bless his cotton pickin heart ) delivered and hooked it all up for this
>old man.  grin     As far a AO-40 ,  I radiate 100 mw less the
>attenuation of 50 ft of LMR 400 to a POP 15 mile away .
>My RF link is not looking at my AO-40 antennas whiich are about 75 feet
>away.    The AO-40 antenna does look in the same direction as the POP but
>generally is higher elevation in that direction.      So far that has
>been no  recognizble interference on my 2.4 gHz AO-40 down link.     I
>run vertical polarizatrion on the ISP and CP on the down link.     The
>down link antenna is a 32 inch solid with three turn helical prime feed .
>The ISP is a 36 inch non-truncated linear polarized dish with a splash
>plate backed verrtical dipole .
>
>Time will tell about all this magic that the FCC believes can be mixed on
>the same frequencies.
>I have been wondering when the 2.4 gHz up link is to be used on AO-40
>because that will no doubt begin a problem somewhere.     The up link
>frequency is in the middle of the ISP channel here.
>
>73's
>
>Joe  K0VTY
>===============================
>
>
>On Wed, 26 Dec 2001 01:56:43 -0500 Dan Schultz <n8fgv@AMSAT.Org> writes:
>> Hasan Schiers, N0AN, wrote:
>> but I can only watch one thingf
>> >If I understand the Part 15 rules correctly, any harmful
>> interference
>> that
>> >they either suffer or cause to a licensed service must be corrected
>> at
>> their
>> >end. However, I have no knowledge of this "technicality" every
>> being
>> enforced
>> >by the FCC. It could be a rule with no teeth.
>>
>> That would seem to be the Big Question.... Does this rule that
>> "protects" us have any teeth? Has anyone, anywhere (in the USA)
>> ever
>> gotten a part 15 user to discontinue operation of the device after
>> reporting interference? Or did your neighbor just laugh right in
>> your
>> face?
>>
>> Dan Schultz N8FGV
>>
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>>
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