We use a Comb Generator to verify site performance before every test. By taking readings on a daily basis, we can identify discreet probems, such as a bad connector or antenna balun, while also monitoring the long-term site characterists, such as frequency nulls developing due to cable breakdown. This does not allow you to plot the transfer funtion of the system, but does allow for a quick way to verify the site integrity. (My Comb generator readings take a total of about 20-30 minutes per day.)
The Comb Generator is also handy for performing site correlations with nearby commercial test labs. We use a Com-Power Comb Generator, Model CG-520, which provides an output of 20 MHz steps from 20MHz to 4.5 GHz. We have seen the stability to be about +/- 2 dB. I hope this is of help! Regards, Randall Flinders EMC Test Engineer Emulex Network Systems [email protected] (714) 513-8012 ---------- From: Gerry McMahon Sent: Wednesday, July 22, 1998 11:42 PM To: emc-pstc Subject: Antenna and Cable Calibration Query (30 - 3000 MHz) ---------------------------------------------------- We use a Bilog antenna, Horn antenna, cables, and a HP 8562A Spectrum Analyser to measure signals at frequencies between 30MHz and 3GHz. We need a set up to verify the operation of our measurement system (antenna, cables and spectrum analyser) before and after every job. We would be interested in receiving any information about possible cost effective methods (the HP 85640A tracking generator for this SA is beyond our budget) for testing our cables and antennas between 30MHz and at least 3GHz. Ideally we would like to be able to plot the transfer function of the antennas and cables, but measurements at a number of spot frequencies (e.g. using a comb generator) may be adequate. We would like to be able to test up to 14GHz, but realise that this may be prohibitively expensive. Thanks for any advice. Gerry McMahon [email protected]
