LR35 flight crew hear frequency interference pulses that ZLA cannot.

Attributes
ACN	478058
Time
Date	200007
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : ave.vor
State Reference	CA
Altitude	msl single value : 39000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc
Operator	general aviation : corporate
Make Model Name	Learjet 35
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	cruise : level
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : commercial pilot : cfi pilot : instrument
Experience	flight time last 90 days : 300 flight time total : 1700 flight time type : 500
ASRS Report	478058
Person 2
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	FAA Airspace Structure ATC Facility
Primary Problem	ATC Facility

Narrative:

For 3 days we have flown the route between pmd and ave at approximately XA00Z. There has been momentary pulses audible on the VHF frequency 135.30. The interference pulses are 12 seconds apart. The controllers don't hear the noise, however, all aircraft do. The interference seems to be some sort of high energy radar antenna scan/sweep. Callback conversation with reporter revealed the following information: reporter advised that this interference has been incurred more frequently in the last month than previously. ZLA supervisor advised that the R2508 complex has been testing radar and GPS interference programs.

Original NASA ASRS Text

Title: LR35 FLC HEAR FREQ INTERFERENCE PULSES THAT ZLA CANNOT.

Narrative: FOR 3 DAYS WE HAVE FLOWN THE RTE BTWN PMD AND AVE AT APPROX XA00Z. THERE HAS BEEN MOMENTARY PULSES AUDIBLE ON THE VHF FREQ 135.30. THE INTERFERENCE PULSES ARE 12 SECONDS APART. THE CTLRS DON'T HEAR THE NOISE, HOWEVER, ALL ACFT DO. THE INTERFERENCE SEEMS TO BE SOME SORT OF HIGH ENERGY RADAR ANTENNA SCAN/SWEEP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR ADVISED THAT THIS INTERFERENCE HAS BEEN INCURRED MORE FREQUENTLY IN THE LAST MONTH THAN PREVIOUSLY. ZLA SUPVR ADVISED THAT THE R2508 COMPLEX HAS BEEN TESTING RADAR AND GPS INTERFERENCE PROGRAMS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.