[evlatests] C-band 6200 MHz RFI IF BD ea28

[Dan Mertely]

I still want to check with the owner to find out why a link
that is from a TX to our west, pointed at a RX site to our
SW is bothering just the north arm here on the plains.

While I'm at it, I've been taking a new inventory of all 5-8
GHz transmitters within 60 Km.
-Mert


On 4/29/2015 12:52 PM, Rick Perley wrote:
>      ... and it's a pity we don't have the funds to pay to have these
> links to go around the Plains of Augustin ...  I imagine the owners of
> these transmitters are unlikely to pay for this ...
>
>      Rick
>
> On 04/29/2015 12:49 PM, Dan Mertely wrote:
>> The 6182-6212 RFI seen on ea28 and adjacent antennas on the north
>> arm is almost certainly due to the State of NM digital data transmitter
>> on Davenport.  The path is from Davenport to Mangus mountain. Both
>> are electronic sites with a number of C and VHF/UHF transmitters.
>> I've attached a screen shot from the FCC search page.  These are all
>> fully licensed transmitters and have a legal right to operate. (See
>> attached.)
>>
>> I will discuss the operation with their engineer to see if they can
>> modify the station parameters some in order to reduce the side lobe
>> hitting our north arm.  Otherwise all we can do is log the frequency
>> and know that it is there.  Updates pending.
>>
>> C-band is filled with these high power point-to-point digital data
>> links.  Multiple paths originate from electronic sites at Davenport,
>> Mangus, Gray Hill, Magdalena, Socorro Peak, Luis Lopez, Lemitar, ...
>> etc.  Sigh!  If only we owned the airwaves!
>>
>> -Mert
>>
>>
>> On 4/13/2015 9:48 AM, EVLA Operations wrote:
>>> Hi Dan,
>>>
>>> Here's the screenshots of the bandpass plots, with the strong noise on
>>> ea28 IF B and D on pad BN7/N28.  It looks to be from around 6182 to 6212
>>> MHz.  Also attached are plots from nearby ea06 (BN5) and ea07 (BN8).
>>> (ea22 was parked, not in use and was at a different band, so there's no
>>> info from that pad.)
>>>
>>> Thanks.
>>>
>>> Matt
>>
>> On 4/13/2015 10:40 AM, Jim Ogle wrote:>     Work Order :  C136361
>> >
>> >   * WO Status        :  OPD
>> >     Asset Number        :  03-08-006.0CM-0VL
>> >     Asset Short Desc    :
>> >     Asset Location        :
>> >     Originator        :  Gardiner, Matt
>> >   * Asset Status        :  ISF
>> >     Safety            :  N
>> >     Plan Priority        :  3
>> >     Origination Date    :  4/13/2015
>> >     Due Date            :  4/13/2015
>> >     Fault Code        :  REPORT
>> >
>> >     Work Requested        :  Ant. 28 C-band IFs B & D showed very
>> > strong RFI from about 6182 to 6212 MHz in bandpass plots with power of
>> > -50 to -30 dBm/channel.  Seen in 15A-070_sb30423823 which switched
>> > between C & L bands from 12:22-15:00 UT 4/13.  ea28 C-band IF B & D pwr
>> > into/out of T304s was weak and fringes very weak. ea28 is at BN7/N28.
>> > ea07 (BN8) and ea06 (BN5) plots also show some RFI, much lower, at the
>> > same freq.  Screenshots of the plots sent to Dan.
>> >
>> >     Employee ID        :  =>IPGRFI
>> >   * Completed (Y/N)    :
>> >   * Date (MM/DD/YYYY)    :
>> >   * Time worked        :
>> >   * Corrective Action    :
>> >
>> >   * Values required when email is returned.
>>
>>
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