[AMPS] L4B

[Roger Rehr]

Bob, You are absolutely right!

I did the experiment of swapping out the 970H for
my 2m transverter/IC-735 combination for the 2mIF,
and the phenemonon disappeared; constant level of
signal across the band band segments in question,
not a 4.4 Mhz "white noise source".

Just "too much preamp gain", which I can easily
take care of now that I know that's what it is.

Good pickup!

Thanks and have a good weekend!


73 from
Roger Rehr  W3SZ ex-AA3QK ex-WA3JYM
mailto:rrehr@epix.net        FN20ah
http://www.epix.net/~rrehr
2 Merrymount Road, Reading, PA  19609
610.670.8687

> -----Original Message-----
> From: Bob Sutton [mailto:bob.sutton@xtra.co.nz]
> Sent: Friday, October 16, 1998 9:43 PM
> To: Roger Rehr
> Cc: amps@contesting.com
> Subject: RE: [AMPS] L4B
>
>
> At 18:49 16/10/98 -0400, you wrote:
> SNIP
> >Any thoughts on another "white noise" phenomenon?:
> >
> >From 2303.800.0 MHz (or 2.303800 GHz) to 2308.200 MHz I have
> white noise
> >S5-S7.  If I just tune up/down 0.1Khz
> >out of this band it disappears.  Like good white noise
> should, it goes to 0
> SNIP
>
> Does your Icom 970 electrically switch in a preamp/special rx
> front end
> over this range?  I suppose 143.8-148.2 in the IF
>
> My IC-275H displays a very similar effect when I use a GaAs
> FET masthead
> preamp for 2M EME.  It has a lower gain broadband receiver
> front end for
> 138-143.7999 and 148.2-174 MHz, and a separate higher gain tuned 2M
> receiver front end that is automatically switched in from
> 143.8-148.1999 or
> there abouts.
>
> 73 ... Bob, ZL1RS
>
>
>



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