Where would one expect to find the low pass filters to use with this isolator? If they are hard to find or are expensive, does anyone have a LPF design the can share which is capable of 50W on 70cm which can be constucted in a die cast aluminum box?
I have an ridiculously expensive and bulky K&L 3TNF500/1000 tunable bandreject filter [which is overkill] I'm using temporarily. Steve WA6ZFT On Saturday 07 May 2005 08:50, skipp025 wrote: > Don't ever throw that catalog out... If it was > worth your time, I'd pay you for some photocopies > or page scans. > > thanks > skipp > > > Micheal Salem <[EMAIL PROTECTED]> ,wrote: > > Skip: > > > > I did look it up when I got home in my ancient M/A-COM > > catalog (From 1982, no less. It is hard to throw this stuff > > away). > > > > For those who are interested, the 7R011 is specified > > at 125 watts. The insertion loss is .9 db typical with > > 1.3 db max. The isolation can be as high as 60 > > db with 50 db typical. That may require breaking out > > the HP435B and an RF head to tune it. But I could get > > a good null right down to zero indication at 10 watts in > > and a 1 watt Bird element on the output and expected > > that I had at least 40 db or more of isolation. It is > > described as a metro style isolator. > > > > The 44004 load that comes with the typical IM > > panel that includes the 7R011 is rated at 100 watts > > and I would agree with Skipp that it would not be a > > good idea to dump more than 100 watts through the > > device. With 125 watts in and an insertion loss of > > .9 db. there probably isn't more than 100 watts > > in the dummy load, but you could be dissipating > > a lot of power in heat in the isolator in an open > > antenna condition. > > > > Micheal Salem N5MS > > Norman, Oklahoma > > > > skipp025 wrote: > > >>I would have to look it up, but I think that > > >>this isolator takes up to at least 100 watts. > > >>That would be when it is in resonance. > > >>I have run 65 watts through it with not > > >>much trouble. > > >>Micheal Salem > > > > > >The port loads are under sized if you want real > > >protection. The units operate just fine at 100 > > >watts fwd power... at least that's what Motorola > > >had been blowing through them for some decades. > > > > > >As long as the antenna system works as it should, > > >the loads are probably ok for lower power levels. > > > > > >But I wouldn't trust the supplied port loads as > > >a failsafe. > > > > > >skipp > > 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/