pdf 6436KB Sep 25 2010 04

others offer custom cables to connect
their decoders, keyers and controllers.
MicroHAM’s multi-device Router software
provides explicit support for the K3.
The logging programs WinTest, N1MM
Logger, DX4WIN, Winlog 32, Logger32,
DXLab, WriteLog and MacLogger DX all
recognize the K3, as do the rig-control
programs Ham Radio Deluxe, N4PY,
N3FJP, TRX-Manager and DXLab. Rose
Kopp, N7HKW, makes custom rig covers
and carrying cases. Nifty Accessories
publishes a laminated, spiral-bound,
quick-reference guide.
Lab Tests and Reviews
Press reviews of the K3 have been quite
favorable:
♦ Performance guru Rob Sherwood,
NCØB, published his measurements of the
K3 in February 2008, and it topped the 75+
rigs on his “Receiver Test Data” chart (see
www.sherweng.com/table.html). Rob
measured a minimum noise fl oor of –138
dBm, two-tone third-order IMD dynamic
range of 95 to 101 dB at 2 kHz spacing
and blocking dynamic range of 140 dB at
100 kHz spacing. Rob is well known for his
groundbreaking critiques of radios and the
measurement techniques used to assess
them. At Dayton in 2007 he focused on
the poor transient response of most thencurrent
DSP radios. Elecraft improved the
K3 AGC to a level that Rob describes as
“perfect” against his lab test that aggravates
a receiver with nanosecond-range pulses. 1
In 2008 he came down on intermodulation
and harmonic distortion in RF power and
audio amplifi ers. It will be interesting to see
which vendors respond most quickly and
effectively to his concerns.
The ARRL review appeared in April
2008 QST and is available to League
members at www.arrl.org. It corroborates
the Sherwood tests within a dB or
so and notes 132 to 139 dB blocking gain
compression, 98 dB fi rst IF rejection and
109 dB image rejection on 20 meters. The
review said, “Overall receiver performance
is right up there with the best radios the
Lab has ever measured, and this is the
fi rst receiver we’ve tested with better than
100 dB IMD dynamic range at the closer
signal spacings.”
In its review, the RSGB’s RadCom called
the K3 “an impressive radio” and “one of the
leading radios for close-in dynamic range
and with excellent features.” The RadCom
review judged the K3 “an ideal radio for use
at home, Field Day or DXpeditions.”
Dave Johnson, G4AON, has published
an extensive online review with detailed
product description, his own informal test
results, photos and scope plots (www.
astromag.co.uk/k3/).
Operating Results and Feedback
The K3 is almost becoming a cult radio.
Perhaps the most visible endorsement was
8 November/December 2008 NCJ
the record-setting February 2008 VP6DX
Ducie Island DXpedition, which used K3s
exclusively to make 183,686 contacts. The
VP6DX team reported, “The outstanding
receiver and transmitter characteristics allow
us to run two positions simultaneously
on any band — even the very narrow 30
meter band — with absolutely no interference.
Good design makes the complex
appear simple: the ins and outs of this
sophisticated radio were quickly mastered
by the operator team, none of whom had
seen a K3 before the expedition.”
At Field Day 2008, the K6NV 2A group
(MLDXCC + Team Truckee) ran three K3s
in a fi re lookout with no inter-station interference.
Most participants were new to the
K3 and had received little or no briefi ng.
They enjoyed the rig from the start, but I
did fi nd myself inserting hints from time to
time to demonstrate features the others
had not yet discovered.
WØYK and AE6Y took three K3s to
Aruba, where they joined W6LD and
KX7M in a 4333-QSO multi-two operation
in the 2008 CQ World Wide WPX CW as
P4ØL. Although they had two radios and
two operators at each position, they often
had the second op listening on the main
K3 sub-receiver for in-band mults. WØYK
remarked that conditions were poor.
“Most of the time signals were right at
the noise level, and the superiority of the
ComTek
Systems
NEW!
2 el. Vertical Switch
Secure Online
Ordering
PVS-2 for 2 el. Vertical Specify band
Offers selectable end fire or broadside directions
STACK - 2 for tribanders 80-10
SYS-3 STACK YAGI SWITCH
RCAS-8 REMOTE ANTENNA SWITCH
VFA-4 Set of 4 vertical feedpoint assemblies
RR-4 Aluminum 60 hole Radial Rings
COMTEK THE 4-SQUARE EXPERTS
ACB-160 ACB-80
ACB-40 ACB-20
ACB-15 ACB-10
CALL FOR PRICES
ComTek Systems
P.O. Box 470565, Charlotte, NC 28247
Tel: (704) 542-4808 FAX (704) 542-9652
e-mail - info@comteksystems.com
Web: http://www.comteksystems.com
K3 receiver really made a difference in
letting us make at least some contacts,”
he said afterward. “Two of our four operators
had never used a K3. Not long into
the contest, most of us avoided using the
PROII because the K3 was so much more
pleasant to listen with.”
WØYK went on to say, “The exceptional
dual receive in the K3 provides outstanding
ability to simultaneously run and
search and pounce the same band.” He
judged the enhanced radio “a joy to use
with negligible learning curve.”
The P4ØL gang used some external
audio switching to achieve a high level of
operator coordination and station fl exibility.
Operators said they also look forward
to planned ability to use the main and
sub-receivers on different bands. They
complained that some front-panel controls
are still locked out while transmitting. This
situation has been improving since fi eld
testing, however.
N5RZ, K5OT and K5TR teamed up for
the 2008 ARRL June VHF QSO Party
using a K3 as the 6 meter radio. They
made 1392 QSOs on 6 meters, noting
that the K3 performed well. They forecast
increased 6 meter contest activity, thanks
to the emerging trend of top-level contest
rigs to include 6 meter capability.
What’s Left?
The “to-do” list at Elecraft remains long,
even though the K3 is now almost feature
complete with respect to its original specifi
cation. It seems so easy to add features
through fi rmware that requests for refi nement
never cease, and Elecraft listens very
well. Some planned additions include:
♦ digital modes other than FSK, AFSK
and PSK 31 2
♦ a band-display panadapter 3
♦ variable-bandwidth roofi ng fi lters
♦ a digital voice recorder
Conclusions
The K3 continues to delight and amaze
its users. The promised feature set is
nearly complete, but regular updates offer
continuous improvement that contesters
demand. The radio is a self-contained,
software-defined radio that does not
require an external computer. It’s a “mustconsider”
radio for contest and DXpedition
rig selection. For many of us, the decision
is a no brainer. Another manufacturer may
leapfrog Elecraft some day, but in 2008
the K3 looks like the hands-down winner
in cost vs performance, size, weight, fl exibility
and absolute performance.
Notes
1 Personal conversation, June 24, 2008
2 Actually, users can inject almost any digital
modulation in audio form. Internal support
for PSK63, higher-speed RTTY, PACTOR
and others is not there yet.
3 Several third-party panadapters are available.
These range from components to specialized
accessories.