John, Don't get your hopes too high, because most dual isolators can only be tuned 3% or so away from the frequency they were manufactured to operate at. For example, my Celwave catalog shows those isolators for the 806-1000 MHz range, but that range refers to the manufacturing capability and not the tunable range. In fact, most manufacturers of circulators and isolators will advise you that the unit must be remanufactured if the operating frequency is moved more than a relatively small amount. A case in point: One local radio club received a dual isolator that was originally made for the 152 MHz commercial band, and wanted to use it on a 147 MHz Amateur repeater. Although it SEEMED to tune down that far, it actually began to generate some spurious signals and got quite warm. It was shipped back to the manufacturer for reworking, at a cost of about $250, and performed perfectly afterwards.
Since your isolators are made for 875 MHz, you might get them up to 902 MHz, but probably not much further. YMMV... 73, Eric Lemmon WB6FLY -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of La Rue Communications Sent: Friday, April 16, 2010 3:03 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Identify Please Thats the one Bill! I have 3 units that look just like that, and 3 that have the "CelWave R.F" on the label. Any HAMs good with Trap Shooting? :-) One more question....if these may stretch to 902 - 928 HAM range, would there be any way to confirm that, since I dont have the proper setup at the moment to verify. Would that be verified with the monitor? John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202
