-Original Message-
From: elecraft-boun...@mailman.qth.net [mailto:elecraft-
boun...@mailman.qth.net] On Behalf Of wayne burdick
Sent: Friday, January 09, 2009 8:53 PM
To: Dave Yarnes
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Using K3's Pre-amp
The noise floor is your
Adam,
While power lines can be a noise source - cracked insulators, dusty
insulators, arcing transformers, etc. - those power lines can pick up
noise generated by some other source and carry it long distances.
A good way to track down noise sources is with a portable AM radio.
Some have loop
on the
Elecraft reflector, as well as on the Contesting
reflector. You could upload the mp3 file to your website and forward the links.
73,
Dave AB7E
Original Message
Subject: Re: [Elecraft] Using K3's Pre-amp
From: "Adam Koczarski" ka7...@ka7ark.com
Date: Mon, January
ka7...@ka7ark.com
To: elecraft@mailman.qth.net
Sent: Monday, January 12, 2009 8:47 AM
Subject: Re: [Elecraft] Using K3's Pre-amp
-Original Message-
From: elecraft-boun...@mailman.qth.net [mailto:elecraft-
boun...@mailman.qth.net] On Behalf Of wayne burdick
Sent: Friday, January 09
-Original Message-
From: dyarnes [mailto:w7...@cox.net]
Sent: Monday, January 12, 2009 9:04 AM
To: Adam Koczarski; elecraft@mailman.qth.net
Subject: Re: [Elecraft] Using K3's Pre-amp
Hi Adam,
Power lines are always a suspect! I have some too that aren't all that
far
away
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Adam Koczarski
Sent: Monday, January 12, 2009 9:47 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Using K3's Pre-amp
-Original Message-
From: elecraft-boun...@mailman.qth.net [mailto:elecraft-
boun...@mailman.qth.net] On Behalf
...@mailman.qth.net] On Behalf Of Adam Koczarski
Sent: Monday, January 12, 2009 11:59 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Using K3's Pre-amp
-Original Message-
From: dyarnes [mailto:w7...@cox.net]
Sent: Monday, January 12, 2009 9:04 AM
To: Adam Koczarski; elecraft
wayne burdick wrote:
Dave,
The noise floor is your entire problem :) It's a fact that the preamp
improves the MDS of the K3 by at least several dB. But if your noise
floor is S4, it will do not good at all, because all lower signals are
already masked by the noise.
To add a
Dave,
Whether you need the preamp will depend on your antenna.
Without involving any numbers, a quick test is to disconnect and then
reconnect the antenna. If the noise level increases when the antenna is
connected, the radio has ample front end gain (in fact it may be too
much - try it with
Thanks for the reminder about this article Don. I just re-read it this
morning. Looks like an easy and cheap project to do.
If you QRZ my call, you'll see I'm smack dab in the middle of the city
and the noise here is pretty rough. An antenna like this permanently
wired into the RX antenna jack
Is Dave's S4 background band noise level unusual or should this be
considered normal? In my first tier suburban location I typically see S2 to
S3 background noise on the 20 to 40 meter bands using cw receive bandwidths
of 500 KKz. The first figure and table in the following link
Hi Everyone,
I don't think this is out of line unless Dave is on CW mode using narrow
BWs? His setup is like mind, it is in the city and he has nearby neighbors.
My antenna is a large inverted 75m Delta loop too low to the ground and I
have S-3 to S-5 noise using 2.8 Khz BW with no pre-amp.
I'm just curious how others are using (or not using) the K3's pre-amp. I
have found few, if any, situations where I felt the pre-amp really improved
a signal vs. the additional noise that is associated with turning on the
pre-amp. It takes a lot of balancing, in my view, between the RF gain
Dave,
The noise floor is your entire problem :) It's a fact that the preamp
improves the MDS of the K3 by at least several dB. But if your noise
floor is S4, it will do not good at all, because all lower signals are
already masked by the noise.
I think you'd be a candidate for some sort of
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