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
>
>
>
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