With Dean's permission, I am posting to the Elecraft reflector the report by
Dean Straw, N6BV, regarding his use of the K3 at K6TA in SS CW. As you can
see, he is a convert!
73, andy, ae6y
[Report by N6BV]:
My primary motivation for operating SS CW for the last 10 years has been to
contribute to the NCCC effort to get/retain the gavel for the Unlimited Club
competition.
This year I also wanted to give K6TA's new Elecraft K3 a real run for its
money on CW, comparing it directly with a Yaesu FT1000MP. I had used a pair
of FT1000MPs in SO2R for seven years operating at the K6TA station.
RECEIVER SETUP
I had used a K3 at the semi-serious CQWW Phone competition at N6RO's place
at the end of October and I was very impressed with it (especially with the
1.8 kHz roofing filter -- SSB sounded very good even with this narrow
bandwidth). But I consider the CW SS as a much higher stress test for any
receiver, because of all the super-strong domestic signals crowding each and
every kHz of any band that happens to be open.
The K3 at K6TA had two roofing filters installed: a 2.8 kHz 8-pole filter
and a 400 Hz 8-pole filter. The venerable FT1000MP had 500 and 250 Hz
filters in both the 8 MHz and 455 kHz IFs.
For both radios I set the AGC decay time constant to "fast." The AGC
constants available in the setup configuration menu were left at factory
defaults in the K3.
I operated the K3 with the preamp "on," but on the FT1000MP I was forced to
set the IPO to "off" (the equivalent of preamp off) to hold down overload.
RECEIVER OVERLOAD
During the CW SS, even on a clear frequency, the FT1000MP has always showed
annoying low levels of what I call "diddley boops" -- more commonly referred
to as "IMD products" -- created somewhere in the receiver chain. (I've been
told that the IMD is better in FT1000MPs that have had the Inrad roofing
filter modification installed, but this had not been done for the FT1000MP
at K6TA.) In SSB operation and in casual CW operation, I've never been
bothered by FT1000MP IMD. But the CW SS is a different sort of animal, as I
said.
By contrast, the K3 exhibited no IMD, even when I opened up the receive
bandwidth to 2.8 kHz and discovered that I was surrounded by S9+30 dB
signals. No "diddley boops" at all. Furthermore, the number of signals with
objectionable key clicks was far less than I heard using the FT1000MP,
especially when the rain static on Saturday night rose to S9+20 dB and I was
forced to use the Noise Blanker on each radio to try to knock down the
noise. The K3's Noise Blanker, used with non-aggressive settings for both
hardware and DSP noise blanking, did help knock down rain static (to only S8
or so) while creating far less overload problems than did the 'MP's Noise
Blanker.
Interestingly, the K3's 400 Hz filter sounded somehow narrower than the 500
Hz filters in the 'MP, more than the nominal difference between the rated
filter bandwidths. I used the 250-Hz filters in the 'MP when I used it for
S&P in SO2R on the second band, while I kept the K3 bandwidth (both roofing
and DSP) set to 400 Hz 95% of the time I used it as the CQ radio. And I didn
't find that I had to use the RIT very often with the 400 Hz filter, while I
did have to use the RIT often when I had to narrow the DSP filtering down to
250 Hz while CQing.
COPYING THE FULL EXCHANGE
The quality of the K3's audio, the lack of overload and the action of the
AGC seemed to make copying a full exchange much easier for me. I feel like I
required less fills on the K3 than on the FT1000MP. (We'll see after log
checking whether my UBN report is actually better.) Even when a QRP station
faded considerably, the K3 had enough gain reserve and sensitivity so that
the station didn't disappear altogether.
In fact, the "presence" of signals on the K3 reminds me of the way my old
Collins 75S3B used to work, with strong signals sounding stronger (without
blasting your ears), while weak signals sounded weaker, but still copiable.
I think Elecraft has gotten the "AGC slope" characteristics right in the K3.
(That refers to the curve of output audio level versus input RF signal to
the receiver.)
I also like the way the K3's RF Gain control works like a conventional AGC
system (the FT1000MP does also), with the S meter rising as the RF Gain
control is backed off, in effect setting the AGC threshold level. (I dislike
the way the RF Gain control works in my Orion I, but that's another story.)
K3 TRANSMITTER
K6TA is located relatively close to N6RO, and he was using two K3s in SO2R
this SS CW. I tuned across Ken's S9+30 dB signal numerous times and marveled
at his complete lack of key clicks. Elecraft got this right on the K3, for
sure. I still heard far too many weaker signals ("only" S9) with really
objectionable key clicks.
Before the contest, K6TA marveled at how the Alpha 87 "enjoyed" the RF
coming from the K3 -- with no leading-edge spikes in power that would
occasionally shut off the amplifier while using the FT1000MP.
Oh yes, this is the first SS I've used Win-Test. It is a pleasure to use,
especially to someone who has used CT for more than 15 years. Win-Test made
it easy to set up packet and worked perfectly without any crashes of any
sort. The ability to point-and-click on unworked stations in the bandmaps
was wonderful. Of course, the number of blown packet spots remains high
enough that I don't think I'll get totally addicted to this kind of
operation!
I experimented with my sleep strategy, but I'm not convinced that helped my
final score. And I'm not going to claim that using the K3 made Sunday
afternoon actually fun during CW SS, but it made it more tolerable. I think
my error rate went down compared to previous years.
I thank Ken (K6TA) and Kay (K6KO) for their wonderful hospitality and for
the use of their great station. They are fantastic hosts.
73, Dean, N6BV
_______________________________________________
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
