Manual - 8500A Series Peak Power Meter - Giga-tronics

Series 8500A Peak Power Meters
D.3.2
PROM PC Assembly
Refer to Figure D-3
The other PC board located in the detector housing contains the PROM and its associated driver. The
fusible link PROM contains RF calibration data for the specific diodes used in the detector. This data
includes the serial number, type, date and place of calibration, and frequency response correction
information. The PROM is read four bits at a time by addressing it with the 12 bit counter, U1. The
PROM cannot be erased. If the response data changes, the PROM must be removed and replaced with a
new one. It must be programmed externally since the PPM by itself has no programming ability.
However, Giga-tronics offers an optional PROM Programmer Accessory Kit, #16976, which works in
conjunction with the PPM to reprogram the PROM.
The thermistor RT1 measures the temperature of the diode mount to correct for the temperature
dependence of the diodes in the detector.
Figure D-3. PROM PC Assembly Schematic
D-6 Manual No. 20790, Rev C, November 1998
Superceded by Revision D, March 2009