Do you have any idea how big a 600 khz notch cavity would be? About 400 ft
We had problems here in the Flint area with two paging transmitters that were 600 khz apart also 152.240 and 152.840 one or both are off the air now. tom n8ies > [Original Message] > From: DCFluX <[EMAIL PROTECTED]> > To: <[email protected]> > Date: 12/21/2004 11:09:12 PM > Subject: Re: [Repeater-Builder] Digest Number 2865 > > > What about building a notch circuit tuned to 600 kHz? And then put > one each on both TX and RX? > > > On Tue, 21 Dec 2004 20:06:10 -0800, Neil McKie <[EMAIL PROTECTED]> wrote: > > > > > > A new VHF paging system just was installed near here in the > > last few weeks. > > > > Rich wrote: > > > > > > 155.820 > > > BEND, CITY OF WNNU934 > > > 100 watts Overturf Butte (Bend) > > > 100 watts Awbrey Butte (Bend) > > > 300 watts Wampus Butte (La Pine) > > > 300 watts Gray Butte (Madras) > > > > VHF paging is apparently here to stay - whether we like it or not. > > > > Neil - WA6KLA > > > > > > Dan Hancock wrote: > > > > > > We had exactly the same problem in Ann Arbor. The > > > pagers were exactly 600 kz apart and up in the 158 Mhz > > > segment. We installed notch filters and sharp > > > band-pass filters on the repeater with some success. > > > Nothing kept it our entirely. I was about to try a > > > crystal filter on the front end when the interference > > > just ended. One of the transmitters was taken off the > > > air. Note though in our situation, the pagers were > > > there first. > > > > > > I can't imagine in this day and age, with the death of > > > VHF paging being on the near horizon, why anyone would > > > put up a NEW VHF paging transmitter. However,if one of > > > these pager transmitters is indeed a new installation, > > > it may be possible to force them off the air. I can't > > > quote the section, but the FCC told me one time in a > > > different interference situation that a new or changed > > > transmitter operation it totally responsible for > > > solving interference related to their transmitter > > > within 5 miles of their transmitter, even if their > > > transmitter meets specs. This rule might possibly just > > > apply in this situation. They have installed a new > > > operation that produces an uncurable mix that wipes > > > out your operation. That mix could be occurring in > > > your transmitter, your receiver, one of the paging > > > transmitters, someone else's transmitter, etc, etc, > > > etc. I would suggest that you immediately contact your > > > nearest FCC field office and discuss this with them. I > > > wish I could give you the section, but the engineer > > > who told me about it never actually quoted the > > > section. > > > > > > Good luck. > > > > > > Dan Hancock N8DJP > > > President, RADAR Inc. > > > www.qsl.net/wr8dar > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
