Regarding power rating of these cavities, I don't think the DB4002 is rated at 3 Kw continuously.
According to the Allen Telecomm Book, they are rated as follows: at .5 db loss 400 watts at 1.0 db loss 350 watts at 3.0 db loss 200 watts Maximum power input (continuous) with insertion loss per cavity. Regarding the question about using them for a duplexer, Because they are bandpass cavities, I don't think you could get enough isolation and separation with these to build a 600 khz spaced duplexer that would be very functional. Looking at the chart, it looks like only about 20 db down about 500 khz away at 1.0 db loss. You would need three of these just to get 60 db of isolation. That would be 120 db from transmitter to the receiver. You would have 3 db of loss plus cable loss and connectors. You can see why the bandpass, bandreject VHF duplexers have much better characteristics. On UHF, it would be a slightly different story. The chart doesn't go out to 5.0 mhz, but extrapolating the 1.0 db loss loop, it looks like 30 down at 5 megs out. Two cavities would give 60 db or so and 2.0 db. I hope this is helpful. Micheal Salem N5MS N�ATH wrote: > Hello Dave - I had a couple of these, if you remove the top insulator they > will tune right on up to 148 and above > to where I do not know but I think they are pass only. Correct me if I'm > wrong. I couldn't give them away so after disassembly > I got more from the local scrap yard for the copper than any one had offered > for the cans. They are rated at 3 KW continous > and are solid copper. The inside tuning device is all silver plated / 3" > with fingerstock > > Dave // N�ATH > > > ----- Original Message ----- > From: "Dave" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Tuesday, October 19, 2004 12:04 PM > Subject: [Repeater-Builder] GE VHF Cavity identification > > > >> >>I have a few of these "barrels" but I cannot find any model or part >>number on them. The only info I have is a tag ties to the top that >>says 106 - 136Mhz. >> >>I'm wondering if these are notch or pass/reject or whatever cavities. >> >>Here is a 44kb picture of what I have. >> >>http://www.kmcnet.net/Pictures/can.jpg > > > 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/
