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.





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