There were a couple of clarification questions concerning the Purchase Description that the engineer has provided responses.

1. In paragraph 4.3.3, how does the range of 20Hz to 20kHz rates relate to the requirement for <1% THD at 1kHz rate, deviations ≤500Hz?

RESPONSE: All specifications are direct from our Air Force calibration Technical order. The "≤ 500 HZ" was added from a bidders suggested change to the PD. We felt this didn't deter from the purpose of what we required in a 8664A replacement.

2. Operating the 8664A Option H15 in its low noise mode is required to achieve the phase noise performance listed in para 4.9, and is a condition of the specifications quoted in the 8664A Option H15 Operation & Calibration manual P/N 08665-90078, dated July 2000. How do the peak deviation requirements in para 4.3.2 relate to operation of the HP8664A Option H15 in the E5504B phase noise test system, as the stated deviation figures exceed those available from the 8664A Option H15 when operating in its low noise linear DC FM mode?. For example, maximum deviation is 100kHz at 1GHz in low noise mode.

RESPONSE: As stated above the specifications are from our Air Force calibration procedure and I just noticed that the spec's from the option 004 were omitted from our calibration procedure table 1 specifications. I will update the PD with the option 004 low-noise mode specifications.

As a result of these clarification questions, there is a revision that is being done to the purchase description. The new purchase description will be revision 8 dated 1 May 2013. Because of this new information, the due date for responses to this solicitation has been extended to 16 May 2013, 4 pm EDT.