[Premium-Rx] RF-590 VLF sensitivity improvement

[Carcia, Francis A HS]

We had a sales guy come in from Chromerics who turned me on to some
interesting display filters. I got enough to do my R2307 and a RA6830.
It does block a little light but it is flat. You might check their web site
and see if you can get some. All displays have update rates or scan rates.
LEDs pull some current so as the buss moves from led to led slugs of current
produce noise. John Collins also found some fine screen to do his 3030. 
I find the quality of coax has a lot to do with leakage. fc 
-----Original Message-----
From: premium-rx-bounces at ml.skirrow.org
[mailto:premium-rx-bounces at ml.skirrow.org] On Behalf Of
ToddRoberts2001 at aol.com
Sent: Friday, February 24, 2006 3:39 PM
To: premium-rx at ml.skirrow.org
Subject: Re: [Premium-Rx] RF-590 VLF sensitivity improvement

After some careful listening today I noticed the RF-590 does have some 
fluorescent display noise at about 15.6KHz with a rough audible broad 3rd
harmonic 
around 46-47KHz and this can drift in frequency a bit. The fundamental at 
15.6KHz is audible even with the antenna disconnected, I would say about an
S-1 
signal level. Interesting that this fluorescent display noise frequency is
very 
close to the standard horiz. osc frequencies used in standard TV sets. Using
an 
outboard upconverter with a 4MHz LO the noise can be just about eliminated 
with the receiver tuned to 4015.6KHz and using shielded antenna connections
to 
an outside antenna. Display noise on VLF would still be a problem if using a

loop antenna or any antenna in close proximity to the receiver though. 73
Todd 
WD4NGG

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