Hello,
Taken from, the http://www.df9ic.de/tech/trxtest/trxtest.html
"The Elecraft K2 also has a low IF design using conventional VCOs which should
result in a good LO noise supression but does not. You may compare the ARRL
test results of the LO noise that Elecraft publishes on their own website and
which is closely within our blocking test result (our measured -95 dB RX
blocking in 20 kHz offset is equivalent to -129 dBc/Hz LO noise). The high
level of TX noise shows that there seem to be design flaws choosing too low
signal levels internally. The AGC threshold is ridiculously high (subjective
impression). I also do not understand why it uses low quality ladder crystal
filters instead of a filter from monolithic duals like any other radio does.
Overall it was the worst HF radio in the test (OK, a 144 MHz IC910H is still
worse...)."
Is the K2 + XV144 really bad combo or the others transverters are much better?
73' SM7VZX
Re: [VHFcontesting] Elecraft XV144 QST Review Online
from [Duane Grotophorst] [Permanent Link][Original]
To: vhfcontesting@contesting.com
Subject: Re: [VHFcontesting] Elecraft XV144 QST Review Online
From: Duane Grotophorst <n9dg@yahoo.com>
Date: Wed, 1 Sep 2004 18:11:53 -0700 (PDT)
List-post: <mailto:vhfcontesting@contesting.com>
--- "Kenneth E. Harker" <kenharker@kenharker.com>
wrote:
> The closest ARRL product review match of a DEMI
> transverter is the DEMI 50-28CK
> (http://www.arrl.org/members-
> only/prodrev/pdf/pr9702.pdf)
> from 1997. The ARRL has never reviewed the DEMI
> 144-28CK. This review was pretty harsh, as the
> transverter as designed required
> significant external filtering to meet FCC transmit
> spectral purity requirements, which also adversely
> affected the receiver performance.
I really wish that the ARRL would do another review of
the current generation 50-28CK along with its higher
band siblings. The current 50-28CK being offered by
DEMI is a VERY different animal than the one that was
reviewed in 1997. In fact it was just few months after
that review that current design configuration was
brought to market by DEMI. Additionally there have
been number of further incremental enhancements to
that design since that late 1997 50-28CK version as
well.
The 1997 ARRL review of the 50-28CK was with the old
"square boxed" version, the newer rectangular (~5 x
7.5 inch) boxed units do have the filtering that was
lacking in the unit reviewed by the ARRL. I have to
believe that that change made a big difference in
performance.
The main curiosity I have with the Elecraft
transverters is how well they hold up thermally? It
just doesn't look like there is enough heatsink on
them for the high duty cycle modes or contesting.
It definitely would be interesting to see all of the
current generation transverters measured performance
specifications next to each other. All of these
measurements done in a lab testing configuration that
uses the same IF radio to minimize the number of
environmental and configuration variables.
Duane
N9DG
EN53bj
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