Jim: I typically pay about US$300 to $400per antenna calibration. I get my LISN's calibrated for $100 each, but only if I send in at least 4 units as a batch.
Remember that the actual work of calibration is only part of the cost. There's the printed data stuffed in a cute plastic liner, not to mention that lithographed 4 color C of C with the foil applique. The actual calibration of the pre-amp is done on a network analyzer, so the job is pretty automated itself. Obviously, you need the gain number. The return loss is interesting, but you really don't use it. And the VSWR is just calculated off the return loss. One comment is that the pre-amp output impedance is likely pretty constant, but the input may waver a bit. Unless you need every dB available, I would make it a practice to use a small (maybe 3dB) attenuator between my antenna (the antenna will "like" it too) and the pre-amp input. Another interesting point is that the pre-amp gain WILL vary over frequency. It also will likely vary slightly with input level. I would ask for two gain figures, one done with a large signal (maybe -30dBm in your case) and another done with a signal just a bit above the noise floor (maybe -110dBm). If you measure strong signals to begin with, don't use the pre-amp. And when you are looking for that really low stuff, use the small-signal pre-amp gain figures. PS: Don't forget to calibrate those coax cables too. Ideally, your spectrum analyzer raw data array must be corrected by merging a separate array for each element in your signal chain. Field = antenna + attenuator + cable + pre-amp + cable + external attenuator + (possible units change) Regards, Ed ------------------------ From: Jim Eichner <jeich...@statpower.com> Subject: Two un-related questions... Date: Fri, 4 Dec 1998 15:37:38 -0800 To: 'EMC-PSTC - forum' <emc-p...@majordomo.ieee.org> > 1. Preamp Calibration: We are being quoted $400 - $500 CDN (say > $260-$330 US) to "calibrate" an HP8447D RF preamp. The quote tells us > that what we are getting for our money is a check of the return loss, > gain, and VSWR. This seems a little involved and a little pricey to me, > but it's the first RF preamp I've dealt with, so what do I know? I > intend to use the preamp between a wideband antenna (a bicon, log > periodic, or combo) and our spectrum analyzer, and I assume the preamp > isn't flat, so I need to enter correction factors vs. frequency for it. > That's all I was really after: a chart or graph of gain vs. frequency, > so that I can set up the antenna-preamp-analyzer combo properly for > pre-compliance testing. Does anyone have any comments on what I really > need to do here, and whether the price I'm being quoted is typical or > not? -------------------------- Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA. USA 619-505-2780 List-Post: emc-pstc@listserv.ieee.org Date: 12/05/1998 Time: 09:13:56 -------------------------- --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
