Please read these most Frequently Asked Questions, if these don't answer your question then email tech_support@aprilinstrument.com.

Q.	Are April Instrument products frequency synthesizers?
A.	They are not. Our generators are programmable YTO's ( Yig Tuned Oscillators ).
Q.	Is the bus GPIB or IEEE488?
A.	No. The bus is BCD ( binary coded decimal ) which is a parallel bus with a strobe line to load the data.
Q.	What is the difference between the 8001/8002 and 8003?
A.	Besides the extended frequency range the 8003 is microprocessor controlled. The 8001/8002 has mechanical adjustments for offset and gain for frequency calibration. The 8003 has no mechanical adjustments. Calibration is done in software and can be done in the field with only a frequency counter.