> "rtoplus" <[EMAIL PROTECTED]> wrote:
> Hi
> I'm thinking about putting 1 or 2 bandpass filters
> on my repeater receiver...got some desense. System
> is: MSR 2000, VHF 2 meter, about 50 watts out of
> the duplexer, 1/2 in hardline, 1/4 in hardline
> jumpers, el cheapo antenna (I know, I know), stock
> pre-amp, etc.
It would be better to find the source of the problem.
If it is desense and what's causing it. Some simple
checks could give you an idea of the problem source(s).
> Question is:
> 1. Is the jumper length from the pass filter to the
> duplexer or PA to the pass filter critical?
Most generic repeater people will say no. But it
does make a difference. I say yes and follow rules
of thumb on certain repeater system cable lengths,
this specific cable being one of them.
> 2. If I use more than 1 filter, is the length of the cable
> between the added on filters critical?
Yes
> 3. Will the interconnect cables within the duplexer need to be
> changed?
Probably not the lenghts.
> 4. Will the duplexer need to be re-tuned?
Yes, everything should be checked and probably re-adjusted
slightly.
> 5. Would I be better off using notch filters as opposed to pass
> filters?
You don't know what the problem is yet... and you
didn't indicate what type of duplexer you are using.
Number 5 alive says... "need input?"
Do you have a isolator or circulator in line?
> I'm at a somewhat low noise site...closest RF stuff is about 200
> yards away with the exception of my micor GMRS UHF repeater (50
> watts) that's co-located at the site.
Nice to be at a low noise site. You might not need the additional
filters. You should find and address the desense problem first.
>
> Thanks
> Bob, GMRS WPVV845, Amateur KG4WAD, LMRS WPXC892
cheers,
skipp
www.radiowrench.com/sonic
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