[Elecraft] third attempt - part 3: K3 Test from Bavaria, translation draft, very long

[Toby Deinhardt]

Somehow the two tries didn't work....


Hi,

for those who do not speak German, the below is the text of my current 
draft of the translation of our K3 test report.

The English version includes a few things which are not in the German 
version yet. Also to see the tables and graphs, please download the 
German version <http://www.bavarian-contest-club.de/news/26,697.html>.

Enjoy...

vy 73 de toby


<< part 3 >>


5) The Proud Owner

by Toby Deinhardt, DD5FZ

5.0) Introduction

Here ends the translation of the German 1.0 version of the test. I would 
like to use this chance to thank Ben and Matthias for the time and 
effort it took to write about their impressions. This was one of the 
reasons I ordered my K3 very early, because my gut told me, this was 
going to be a very interesting radio, and worth taking a close look at 
within the Bavarian Contest Club <http://www.bavarian-contest-club.de/>.

Also, I wanted to have a good radio for myself.

You may wonder why I refer to this as version 1.0. The three of us hope 
during the next several weeks to add further measurements and new 
insights as we gain experience using the K3 in the upcoming major 
contests. At the present time, we plan for Ben and Matthias, both 
excellent CW operators, to be in the CQWWDX 160m contest and I plan to 
use the K3 in RTTY WPX, which should interesting. My last RTTY QSO is at 
least 20 years in the past. Also at least one of us, using the K3, will 
be QRV during CQ 160m SSB, ARRL International DX, Russian DX etc. 
contests. In other words, as the K3 firmware evolves and we learn more 
about the radio, we will be updating this document.

5.1) The K3 Configuration

My K3 during the tests for version 1.0 had the following configuration:

K3/100    100W Transceiver (Modular Kit) with standard TCXO
KAT3        Internal ATU with 2nd Ant. Jack
KFL3A-400    400 Hz, 8-pole roofing filter
KFL3A-1.8K    1.8 kHz, 8-pole roofing filter
KFL3A-2.1K    2.1 kHz, 8-pole roofing filter
KFL3A-2.7K    2.7 kHz, 5-pole filter (standard filter included with the K3)
KFL3A-6K    6 kHz, 8-pole roofing filter
KXV3        Transverter Interface w/ RX Ant. I/O

The firmware was updated more than once during the test period, so some 
of the comments in this document may be referring to features or bugs 
which have since been fixed or changed.

I still have the following items on back order or have not installed 
them yet:

KBPF3        General Coverage RX Front End Filters
KRX3        High Performance Subreceiver
KFL3A-400    400 Hz, 8-pole roofing filter (for the KRX3)
KFL3A-1.8K    1.8 kHz, 8-pole roofing filter (for the KRX3)
KFL3A-2.1K    2.1 kHz, 8-pole roofing filter (for the KRX3)
KFL3A-2.7K    2.7 kHz, 5-pole filter (standard filter included with the 
KRX3)
KFL3B-FM    FM b/w, 8-pole roofing filter
KDVR3        Digital Voice Recorder

The final configuration will see the KBPF3 installed on the secondary RX 
and I will move the 6kHz filter from the main to the secondary receiver, 
allowing me to install the FM filter in the main RX.

There has been much discussion on the Elecraft reflector over the last 9 
months about which configurations make sense and which do not. Mostly 
this has dealt with which roofing filters are needed. Briefly, my 
configuration was based upon the following thoughts:

- As my landlord does not allow the installation of any antennas, I 
often operate from vacation QTHs such as 5B, SV, 4O, CU etc. The fewer 
boxes needed the easier the journey. In the past my K2s have mostly 
performed very well in this role.

- I am and never was very good at CW. The frustration of practicing with 
a computer for an admittedly wonderful mode which I could not use on a 
daily basis (see above) made me eventually stop. This means most of my 
operation is in SSB.

- I actually enjoy SSB contesting!

- When traveling, I wanted to have good AM reception of international 
broadcasters.

- In the past one aspect of the TS-850 which has been a real 
disadvantage is the lack of a second RX, especially when working NA and 
EU at the same time on 40m and 80m.

I know that some my readers will feel that installing 1.8kHz and 2.1kHz 
in the K3 is overkill and will not bring any real improvement. This may 
or may not be correct, but my experience has been, every tiny little bit 
helps when fighting it out in the european zoo on 40m during large 
contests. Even if the advantage is mainly psychological, I suspect that 
this will still mean a few QSOs more on 40 with both filters. QSOs, 
which wouldn't have been possible with only one.

When considering which filters to install in a K3, remember that the 
main selection takes place in the DSP and the roofing filters are there 
to protect the ADC, IF amps and second mixer, which by the way is not a 
high end mixer like the first mixer. These means low distortion and the 
first 30 or so dBs are important, and not so much the ultimate rejection.

5.1) The K3 Build

I am writing this several weeks after the build, so the details may be hazy.

I bought the K3 as a so called no solder kit. This means no solder to 
melt, no torroids to wind, no burnt fingers (always brings me luck when 
building things... hi) and almost nothing to align. It also means about 
a hundred things to screw together, plugging things into each other, 
searching for small bits and pieces (this hasn't changed) and a much 
shorter build time.

My K3 arrived exactly 200 days, almost to the hour, after my initial fax 
to Elecraft. That evening I went from work directly to DK0MN, our club 
station in Munich <http://www.darc-c12.de/>. By the way, my box was 
brown and not white.

I quickly unpacked everything, and, with boxes in boxes and much 
padding, found no damage. Because I had read the construction manual 
several times before the K3 had arrived 
<http://www.elecraft.com/K2_Manual_Download_Page.htm#K3>, I immediately 
started to build the K3. I tend to think that inventories are for 
sissies and up to now Elecraft's track record was very good.

The quality of the boards is top notch, a feast for the eyes and things 
were going along well. The assembly manual was just the thing for 
mechanical klutzes like myself. Yep, I was zipping along, reading the 
fortune cookies (the small bags with parts and a piece of paper saying 
this assembly was done by ...) and being amazed that so many bits and 
pieces were evolving quickly into a cool radio, when, all of a sudden, 
the manual wants me to install the TCXO.

Now, I knew I had seen the fortune cookie with TXCO board, and it was 
where I had left it, but, that's funny, no TXCO in the bag, only the board.

**PANIC**

Oh my god, I've lost one of the most important parts. After about an 
hour of searching a 5m x 4m room, I concluded that Elecraft had actually 
made a mistake. A short telephone call with Scott in Aptos and an email 
later my TXCO was in the mail. Kudos for the quick reaction. But it gets 
worse. The next morning (Friday) on my way to work, sitting in the 
subway, I was doing a sissy thing, a mental inventory, when I realized 
that I had not seen my KBPF3 anywhere. Another email was sent to 
Elecraft informing them, there was the possibility that another part was 
missing. On Saturday, back to DK0MN, spend another hour or so searching, 
confirm that Elecraft had also forgotten to ship this and return home 
feeling a bit miffed.

However when I turn on my computer, I find the following in a mail from 
Elecraft: "I sent the KBPF3 yesterday. I know you weren't sure, but when 
I checked the paperwork here it look likely it was missing so rather 
than delay over the weekend I went ahead and sent it so that you could 
have it."

They actually sent me a replacement for a part which only might have 
been missing! I thinks this says a lot about a company and how seriously 
they take customer support.

As soon as this missing parts arrived, it took about a week, I finished 
the assembly of my K3.

On the whole the construction went without a hitch but could have been 
more streamlined, which by the way has been improved in the newer 
versions of the manual. There were no glaring errors and when Elecraft 
says something might be a tight fit, they really mean it; I was worried 
I was going to damage my main board while installing the 100W PA. It is 
also worth noting that the number wires which have to installed is 
minimal, leading to a very tidy inside appearance.

5.2) K3 Gripes

Most of these are on Elecrafts to do list and will be fixed "soon".

- You can not use more than one audio input at a time. A bummer when you 
want to work with an external voice keyer. This is currently being 
worked on in Aptos.

- The missing band syndrome. More about this later (see part 6).

- Lousy KUSB drivers. I had at lot of problems updating the firmware and 
with WinTest using the old drivers. If you order the KUSB, which is a 
very nice USB to serial interface, then do not use drivers on the CD! Go 
to the Prolific website and get the newest drivers 
<http://www.prolific.com.tw/>. Elecraft also now recommends this. The 
CD, by the way, is one of those miniature CDs which many drives can not 
handle.

- I also have the feeling that the SSB modulation could be "more 
powerful", but have not taken enough time to try enough settings of the 
TX equalizer, compression, mic gain, etc. On the other hand, it appears 
impossible to make the K3 sound "bad". But, on the other other hand, a 
tiny bit of "badness" during contests is not that bad.

- My old MH2 microphone does not work well with the K3. When I push the 
PTT there is a very short noise spike with a very high tone. It takes 
the ALC several seconds to recover from this. According to Gary from 
Elecraft, they wanted to look into this, and I have not tried using this 
microphone since November, so this might be fixed now. With my headset 
and foot switch this has never happened.

- I wish Elecraft had not moved the AF gain knob. It does take a bit of 
getting used to. Originally the AF gain was below the RF gain, instead 
of the other way round. By the way, many of the pictures of the K3, 
including the one in this document, are from prototypes before the knob 
switch occurred.

5.3) K3 Praise

- The radio is easy to use and if you come from a K2, the tap and hold 
philosophy and the radio itself are almost instantly understandable. 
Nonetheless, it is well worth your while to study the manuals.

- The RX is eerily silent. I have always found the TS-850 very tiring 
because of the high level of audio noise. This also applies to many 
other radios by Kenwood and Yaesu. I have not used many ICOMs so I can 
not make a comparison to their radios. This was a big plus during the 
ARRL 10m contest here in Germany. The conditions were terrible and the 
signals very weak. With tired ears I could not have worked some of the 
stations I did work. The K2 is also an ear friendly radio.

- Continuous bandwith, shift, low- and high-cut filter tuning is just 
plain cool. Especially when it works as well as it does in the K3.

- The DSP code does not sound like many digital radios: No artifacts and 
almost like a really good analog sound.

- I actually had a CW QSO during Stew Perry! I know that for most of you 
this does not sound special, but for me it was. It was a great idea to 
add various decoders to the firmware.


6) Elecraft says

Wayne, N6KR and chief designer of the K3, knew that we were working on 
this report, and asked me to give him a chance to see the report at an 
early stage, so that he could point out errors, fix anything which might 
be broken and make comments. I have been glad to do this. The below is a 
summary, at time paraphrased by myself, of some of our discussions.



Wayne: We've also developed a couple of simple hardware modifications 
that you will probably want to add to any test unit. One corrects the 
"soft" keying in CW mode. The other increases the onset point of 
hardware AGC, which can help when you're using a DSP bandwidth that's 
narrower than the crystal filter.

Toby: We will be doing these modifications and we will add our results 
to this report.



Wayne: The K3 has a fairly low-gain preamp. It is designed to improve 
MDS to -136 dBm or better without compromising dynamic range any more 
than necessary. Your later tests show that it is working as intended. I 
should mention that we also have an external K3 6-meter preamp product 
in the testing phase right now. It attaches directly to the RX ANT IN 
and OUT jacks, which can be selected on a per-band basis. It improves 
6-meter MDS to better than -142 dBm.



Matthias: Phase noise is very difficult measure accurately with a hobby 
laboratory.....

Wayne: I suspect the hump near 10 kHz is a byproduct of test equipment. 
In all of our tests, phase noise decreases monotonically, reaching a 
limit of better than -150 dBc/Hz. If you have a synthesizer module you'd 
like us to test, feel free to send it to us.

Wayne: Eric, just in case, I think we should arrange a synth module 
swap. This is important because low phase noise is a hallmark of the K3 
and one reason for the excellent dynamic range.

Matthias: Before swapping the module, I'll ask at work. We have a fairly 
new phase noise measurement system and I might be able to use it to 
check the present synthesizer directly.



Ben: Pushing the Band Up and Band Down buttons does not always bring one 
to the next amateur radio band...

Toby: The missing band syndrome...

Wayne: I'm surprised that this occured. Recent firmware revisions should 
have cleaned up this behavior in general. There are still some issues 
remaining in wide-range tuning of the VFOs, and I'm working on those. I 
suggest you use FREQ ENT to re-set the VFOs within each ham band, and to 
load the latest firmware.