[1000mp] Mark V Front-End Amp Setting.

Fri, 12 Dec 2003 10:00:22 -0600

If we're talking preamps, the "Tuned" selection results in a separate,
less-sensitive preamp for 1.8-7 MHz and a separate, more-sensitive preamp
for 24-30 MHz.  The Flat preamp is used for frequencies between  the tuned
pair.  The VRF "Preselector" on the Mark-V is a different animal, but I
don't think that was the subject of this "Front-End Amp Setting" test.

Randy didn't state the frequency he used for his tests.  If his measurements
were made on 160 or 80 meters, then he observed just what he was supposed to
see.

Bill, W9NHQ

----- Original Message ----- 
From: "Bill Miner" <[email protected]>
To: <[email protected]>
Sent: Friday, December 12, 2003 9:11 AM
Subject: Re: [1000mp] Mark V Front-End Amp Setting.

> Randy,
>
> I believe that the "tuned" input is all passive and is separate from the
> tuned or flat pre-amps.  It does add some small amount of loss but if
> you are in a high RF environment it may reduce QRM from adjacent
> frequencies.
>
> 73,
> Bill - K6WLM
>
> WX5L wrote:
> >
> > Hello,
> >
> > I wanted to share this observation I recent made with my Mark V.
> >
> > With a signal generator I injected the theorical s-9 signal level of -73
> > dbm. Indeed the s meter read s-9 on all bands. I've always set my
receiver
> > front-end to "tuned" in menu 8-4 but as a curiosity test I switch to
"flat"
> > and found a slight increase in sensitivity as indicated on the s-meter
of
> > about 6 db. Not much really but could make the diffference under very
weak
> > signal situations.
> >
> > I would have thought in the 'tuned" setting and having seperate tuned
> > amplifiers for the low and high bands I would notice higher gain but
that
> > was not the case.
> >
> > This slight increase would probably be unnoticable with on-air copy due
to
> > qsb ect but with a steady signal it was obvious.
> >
> > This was not a sophisticated testing procedure and the results were
contrary
> > to what I thought.
> >
> > 73,
> > Randy
> > [email protected]
> > Thibodaux, Louisiana