Department of the Air Force, Direct Reporting Units, 10 ABW/LGC, 8110 Industrial Drive, Suite 200, USAF Academy, CO, 80840-2315

58 -- PUBLIC ADDRESS SYSTEM REPLACEMENT SOL F05611-99-T-1817 DUE 091599 POC Scott Walker, Contracting Specialist, Phone (719) 333-6081, Fax (719) 333-4404, Email scott.walker@usafa.af.mil -- Bruce Taylor, Contracting Officer, Phone (719) 333-2869, Fax (719)333-4747, Email WEB: Visit this URL for the latest information about this, http://www.eps.gov/cgi-bin/WebObjects/EPS?ACode=M&;ProjID=F05611-99-T-1 817&LocID=479. E-MAIL: Scott Walker, scott.walker@usafa.af.mil. Reason for Modification: Change response date from 10 Sep 1999 to 15 Sep 99, provide the following additional information to the para entitled Contractor is required to: 3. Test, equalize, adjust, and balance the entire Falcon Stadium Main Speaker Cluster, add and correct NOTES to the Combined Synopsis/Solicitation posted 01 Sep 99. TEST EQUIPMENT: The contractor shall will supply, utilize, and be proficient with the following at a minimum the following test equipment, to conduct the specified tests, adjustments, and demonstrations set forth below: FILTER SET: One third octave band filter set meeting ANSI S1.11 specifications; SINE WAVE GENERATOR: Continuously sweep from 20 Hz to 20,000 Hz within -- or+1 dB with less than 0.5% THD; IMPEDANCE METER: At least 250Hz, 1kHz and 8 kHz with a range of 0-100k ohms; OSCILLOSCOPE: At least 20MHz bandwidth and external horizontal inputs. Sensitivity of 10 mV/division or less; DISTORTION ANALYZER: Automatic tunable 1/10 octave band wave analyzer allowing reading down to and including .001% THD; REAL-TIME ANALYZER: One third octave band meeting specifications of ANSI SS1.4 and S1.11; PINK NOISE GENERATOR: Capable of producing at least -50 dBV to 0 dBV of pink noise; AC VOLTMETER: Frequency response of + or -- 1dB from 20 Hz to 20,000 Hz,0.001 volts rms to minimum input impedance of 0.01m ohms; PHASE TESTER: Capable of measuring electrical and acoustical polarity using an encoded sine wave with low, low midrange, midrange high, and high output frequencies; TEF (Time Energy Frequency) Analyzer: Capable of measuring time, energy and frequency domain to include Nyquist curves and 2nd/3rd harmonic distortion plots; SLM: Meets ANSI S1.4 specifications for Type 1 SLM level meters; Other miscellaneous cabling and connectors required to perform tests, equipment setups, or equipment checkouts; Other miscellaneous cabling and connectors required to perform tests, equipment setups, or equipment checkouts. TESTING: If applicable, the following tests will be performed by the contractor: TRANSDUCER LINE IMPEDANCE: Measure the impedance of each line exiting the equipment rack with the line disconnected from its normal driving source. Confirm impedance values within + 10% of the value calculated for the circuit based upon the parallel impedance values plus the resistance of the cable. Record the impedance at 1000 Hz for full range devices. Verify the minimum load impedance's are not exceeded and there are no electrical short; HUM AND NOISE LEVEL: Adjust the gain controls for the optimum signal-to-noise ratio. This adjustment should be such that full output would be achieved with 0VU; POWER OUTPUT AND SIGNAL LEVEL ADJUSTMENTS: Measure the electrical distortion of the overall system. Set variable filter sets for a flat response. Apply a 1000Hz sine wave signal at each input at a level required for the specific type of input. Use a distortion analyzer to measure and record the output level and total harmonic distortion of the amplification equipment. Make all measurements with the loadsactually incurred in the system; PARASITIC OSCILLATION AND RADIO FREQUENCY PICK UP: Check to ensure the system is free from spurious oscillation and radio frequency (RF) pick up, both in the absence of any input signal and also when the system is driven to full output potential at 1000 Hz. Using a hand held radio provided by the Public Address Maintenance Workcenter (10 CS/SCMRP) to check the above; POLARITY: Phase all lines identically with respect to color coding. Visually inspect all transformer primary and secondary wiring to insure proper phasing; FREEDOM FROM BUZZES, RATTLES AND OBJECTIONABLE DISTORTION: Apply a slow sine wave sweep from 100Hz to 10,000Hz at a level 6dB below the rated power input levels. Listen carefully for buzzes, rattles and objectionable distortion. Correct all causes of any defects; GAIN CONTROL SETTINGS: Establish "normal" settings for all gain controls. All gain controls will be adjusted for optimum signal-to-noise ratio and signal balance. Clearly mark all knob and control settings with a red nail polish dot; LIMITER ADJUSTMENT: Adjust all limiters so the peak LED illuminates at the failure point of the transducer to be protected. Adjust RMS limiters for -3 DB of compression at the same failure point; FREQUENCY RESPONSE: The overall space average frequency response within each area served will be within the limits given below. Test signals will consist of a broad band pink noise signal applied to the system input. System performance measurements will be made using a calibrated ANSI S1.4 type 1 SLM set for slow meter damping and flat response. The SLM will be positioned 5 to 6 feet above the floor within the space served by the system. The system gain will be set to provide octave band levels at least 15dB above any background noise levels in any octave band at the measuring location for these areas. Provide a hard copy of the average frequency response based upon the measurements at least ten locations to the Public Address Maintenance Workcenter (10CS/SCMRP). Ensure identical measurements are obtained when using the TEF measuring methods and compare the real time response using pink noise; Using the TEF Analyzer, measure the STI after filter set adjustments are completed. Provide the Public Address Maintenance Workcenter (10 CS/SCMRP) with a hard copy of the results. NOTE: Results of all tests performed are to be submitted, reviewed, approved and accepted by, 10CS/SCMRP, POC assigned to this project. NOTE: Contractor will be required to remove existing speaker horns on top of scoreboard and retrofit as required to accommodate new components. Offers are to be received at the Operational Contacting Office 8110 Industrial, Dr., Ste 200, USAF Academy, CO 80840, No later than 15 Sep 99, 3:00 PM, Mountain Standard Time. Questions and proposals may be faxed to (719)333-4404 or Email to the addresses above. Offers are to be received at the Operational Contacting Office 8110 Industrial, Dr., Ste 200, USAF Academy, CO 80840, No later than 15 Sep 99, 3:00 PM, Mountain Standard Time. Questions and proposals may be faxed to (719)333-4404 or Email to the addresses above. Posted 09/07/99 (D-SN377157). (0250)

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