Posted by
Edward R Cole on
Jul 08, 2012; 7:22am
URL: http://elecraft.85.s1.nabble.com/KX3-Receive-Performance-Below-1500-kHz-tp7558831.html
If this is true then the spec on page 51 of the KX3 manual is very
misleading where is states:
"310 kHz - 32 MHz and 44-54 MHz..."
I was looking forward to using the KX3 on the new 630m Ham Band
recently approved by WRC-2012:
472-478 KHz. The K3 operates down to 490 KHz but no lower so
unusable on the new ham band. The KX3 "appeared" to be the first
commercially mfd radio able to operate down there. If not then this
is a BIG missed opportunity.
I use a Clifton Labs Z-10020 MW BC Band Reject filter (540-1700 KHz)
which rejects signals inside that band. Signals seen at -50 dBm are
reduced to the the -110 dBm noise floor, whereas the signals below
540-KHz are unaffected below about 515 KHz. I have used it with the
K3 and my SDR-IQ (which tunes to 500-Hz).
There was discussion last fall that the KX3 might be capable of
transmitting on 630m.
I would like the official word on this before publishing my paper
reviewing the KX3 at MUD-2012.
630m will remain the province of the "experimenter" if no commercial
"shelf-ready" equipment is available.
73, Ed - KL7UW
I run 100w into a 43x122 foot inverted-L on 600m under the license WD2XSH/45.
------------------
Date: Sat, 7 Jul 2012 08:15:31 -0500 (GMT-05:00)
From: Mike Morrow <
[hidden email]>
Subject: [Elecraft] KX3 Receive Performance Below 1500 kHz
To:
[hidden email]
Message-ID:
<
[hidden email]>
Content-Type: text/plain; charset=UTF-8
A discussion of KX3 MF lack of sensitivity recently took place
on the KX3 list. The KX3 should not be considered really
usable below about 1500 kHz, as Wayne explsined:
---- Original Message (from KX3 list)
> I thought there was some advantage to AM BCB reception
> to be had with the KXAT3.
If a KXAT3 is installed, harmonic images are attenuated,
but this has little effect on signal strength.
> Why wouldn't the T/R PIN diodes be as well protected by
> high pass filtering that rolled off below 400 kHz rather
> than 1500 kHz
The carrier lifetime of the diodes is roughly 1.5 microseconds.
This means that strong signals at the low end of the broadcast band
could cause IMD (IP2) if not attenuated. The HPF provides
about 20-30 dB of rolloff by this frequency, ensuring that
this isn't a problem. The KX3 is optimized for ham-band use
so this is entirely appropriate.
Wayne
73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-?
DUBUS Magazine USA Rep
[hidden email]
"Kits made by KL7UW"
http://www.kl7uw.com/kits.htm======================================
______________________________________________________________
Elecraft mailing list
Home:
http://mailman.qth.net/mailman/listinfo/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.html