[R-390] receiver sensitivity testing

[wb5uom at hughes.net]

Yes I agree, sort of.

If I do the standard test and can follow the 1000hz tone all the way down 
with my ole going deaf hearing,
I think I should be able to do the same test in SSB mode with voice using my 
aforementioned service monitor
(I will let others say if its lab grade or not- aeroflex 3920)
Covers on, screws tight and a 1 foot coax from generator to antenna input, 
in my living room wih not much electrical on in the house


David WB5UOM

----- Original Message ----- 
From: "Tisha Hayes" <tisha.hayes at gmail.com>
To: <r-390 at mailman.qth.net>
Sent: Thursday, March 01, 2012 11:44 AM
Subject: [R-390] receiver sensitivity testing


> If you are looking to test down in the -130's and -140's you would
> really need to do it in a Faraday cage with a lab-grade signal
> generator, precision RF connections and attenuators. There are just
> too many variables and outside sources of noise to make any numbers
> you get down there to be meaningful.
>
> Everything would need to be buttoned up tight, every cover in place,
> all the screws and modules completely in place, the best tube
> line-up's in the right positions and pulling your monitored signal off
> of the diode load connection to minimize distortion from the audio
> deck.
>
> One thing the R-390A does not suffer from is a lack of sensitivity. If
> anything was to be done to enhance certain receiver characteristics it
> might be to improve the selectivity and IP3 points. Roofing filters,
> changes in the way the IF's are staggered tuned, etc... could all help
> you with selectivity but at the trade off of any high fidelity
> performance with the 16 khz filter position.
>
>
> -- 
> Ms. Tisha Hayes/ AA4HA
> -
> "Life isn't about how to survive the storm, but how to dance in the rain"
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