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I’m the proud father of three Elecraft radios (K2 #1770 born in 2000, K3 #2887 born in April 2009, and K3 #1297 of uncertain vintage) plus a KPA500 amp, W2 wattmeter and P3 panadapter.

I built most of them from kits, partly to save a few $ but mostly because I enjoy making things. Like Heathkit years before, the Elecraft kits are excellent, providing detailed step-by-step instructions, all hardware and electronic bits (solder-it-yourself components for the K2, pre-made modules for the K3), and if needed responsive online support from Elecraft’s chief engineers plus the community of builders and fans. Everything worked first time and is a joy to use. The thrill of hearing the first callsigns on a receiver you’ve just finished is hard to beat - actually working DX with a homebrew transceiver is superb. These are not beginners’ projects though. The K2 took me a month of evenings to build and the K3 an intensive day. While the K3 is a ‘no-solder’ kit (basically assembling the case and plugging in pre-built modules and circuit boards), learn to solder properly before you try building the K2!

Quick links

  1. The K2 suitcase set
  2. The K3, a serious radio for serious contesters, DXers and DXpeditioners
  3. W2 wattmeter
  4. KPA500 QSK amplifier

Elecraft K2

Both my Elecraft radios are physically compact and lightweight. The K2 is about the size of a car radio. The K3 is about the size of a large box file, similar to other mid-sized ham transceivers but considerably smaller and lighter than the FT1000 etc. Pelican waterproof cases or aluminium flight cases with foam inserts are a good way to protect them both when travelling, and are small enough to travel in the cabin as hand baggage ...

K2 suitcase set

My QRP ‘suitcase set’ consists of the K2, some antenna wire and string, a Palm mini paddle, pen and paper, and a small switched-mode PSU to recharge the rig’s internal 12V SLA battery, carefully packed into the foam insert and ready to go in an emergency (living on a major fault line in one of the world’s most active earthquake zones, that’s no joke). As well as in the shack on decent antennas, I’ve used the K2 portable stylie on picnics and holidays in France, Brussels, and New Plymouth feeding wires tossed over convenient lighthouses etc. The auto-ATU will tune almost anything but wire dipoles, doublets, verticals or loops make more efficient antennas than random lengths of wet string.

I own the 100W PA kit for the K2 but haven’t found the time to build it yet. QRX. I might build it into the separate EC2 enclosure, leaving the base K2 as a more portable QRP radio.

Elecraft K3

The K3 is more sophisticated than the K2 with a fully digital IF and AF using DSP for demodulation, noise reduction, AGC etc., on receive and digitally generating the modulated waveform on transmit. Mine has the second receiver option (giving SO2V at last, if not SO2R!). I can monitor the beacons and CW end of 10m simultaneously. It is handy to be able to pick out callers in a pileup and figure out where the DX is listening (in one ear) while simultaneously listening to the DX (in the other ear).

The K3 has a true diversity mode with two independent receivers, phase locked by dint of sharing a common reference oscillator. Using a 30m fullwave loop on the subRX in my right ear and the beam, vertical or dipoles on the main RX feeding my left ear, I find diversity mode is worth about 3dB due to the loop partially filling-in QSB dips on the main antennas. Signals sway from side to side in my head, floating across the gap between my ears (no comments please).

Whereas the K2 covers the main 9 shortwave bands 160-10m, the K3 also covers 60m and 6m, with an optional internal 2m transverter.

The K3 is not perfect however. Check out the spectrum anomalies on this BeaconSee output for example: the horizontal white and pinkish lines are most likely artifacts of the K3’s DSP:

K3 BeasonSee screenshot

By comparison, the following screenshot from my TS850 shows no such obvious artifacts:

BeasonSee screenshot

There are a few K3 mods and add-ons:

  • Solve a nasty transmit spur on K3s released in mid-2009 by removing a single capacitor.
  • Rather than constantly reaching over to the rig or adding some sort of external switch box for the DVR/CW memory buttons (M1-M4 plus the REC button used to interrupt sending), Logger32’s Radio Control Panel lets us define up to 36 macros. The commands to trigger and abort the memories are easy enough, while more complex ones to set up split etc. just take a bit of patient experimenting to get right.
  • The Elecraft KAT500 500W auto-ATU is cool if you use 500W or so. Not so cool for our 1kW limit in NZ.

Connecting the K3 to your PC

The K3 comes as standard with an RS232 serial port through which it can communicate with logging software, passing information such as its frequency and mode in either direction. RS232 is a well-defined standard. The K3 has a 9 pin RS232 connector.

If your PC has an unused real RS232 serial port, you simply need a suitable cable to connect it to the K3. However most of us need a USB/RS232 serial converter gizmo since modern PCs have USB ports but no RS232 ports. Some hams will insist that you need a particular chipset in the converter to avoid problems, but I guess I have been lucky: all mine have worked OK. USB/RS232 converters are cheap as chips so don’t worry about chipsets, just take a gamble. Buy one and try it. If you are highly risk-averse and have the $$, simply buy the one from Elecraft.

Here’s how to connect your PC to your K3 (I will assume you are using a USB/RS232 adapter on a Windows 7 machine - if not, your mileage may vary):

  1. Before you plug your USB/RS232 adapter in, install its driver from the CD that came with it.  Usually, just putting the CD in the PC will get it to start the install.    [You might be lucky and not need a driver install if it is already included in Windows.  Some of them are but they tend to be generic drivers while the one provided by the manufacturer with the adapter is more likely to work properly.]
  2. Now plug the USB/RS232 adapter into the PC’s USB port (any one should work).  Wait a moment for the PC to recognize it and find the driver you have just loaded.  A pop-up message should appear bottom right of the desktop saying something like “New USB device found – installing driver” and then shortly after “USB serial adapter installed”. 
  3. Now figure out which serial port the adapter is using: open Windows Device Manager.  The easiest way is to hold the Windows key and tap the Pause/Break key, then Device Manager is the top left option.  Click it to run it.  One of device types listed should be “Ports (COM & LPT )”: click the little arrow to the right of that line to open up a list of all the serial ports on your machine.  One of them will be the USB/RS232 adapter you have just installed, usually called something simple like “USB Serial Port (COM2)”, in which case  COM2 is the number you need for step 6 (keep a note of it).  [If you have several ports listed and don’t know which one it is , you can simply try them all by trial-and-error, or unplug the USB/RS232 adapter and wait a second to see which one disappears, then plug it back in to make it reappear.][If your USB/RS232 is using a COM port number above COM8, you will have to reconfigure it to be able to use it in N1MM – this is achieved in Device manager by right-clicking the com port line and selecting Properties Port settings -> Advanced, then choose a COM number in the range 1-8, one that isn’t already in use by another device.  Hopefully you won’t have to do this.]
  4. Plug the RS232 end of the USB/RS232 adapter into your K3: there is only one RS232 port on the K3’s rear panel.
  5. Configure the K3’s serial port: press and hold the K3 menu button, then find the RS232 settings by turning the VFO B knob.  I normally select the maximum speed (38400 baud).  Also configure the PTT/CW key setting to be rts-dtr (you will be using the dtr setting to send CW now, but the rts PTT setting can be used to put the rig in transmit for audio data modes later if you want to play with RTTY etc.).  Tape the Menu key to exit the settings.  [Optionally you can put the K3 into TEST mode by holding the mode up button, so that you can test the CW sending in a moment without actually transmitting.  TX will flash on the display while in TEST mode.  Hold TEST again later to put the rig back into normal transmit mode.]
  6. Start your logging software and get it to connect to the K3 - instructions for Logger32 and N1MM follow below.

Configure N1MM to connect to the K3

N1MM K3 radio setup
  1. In N1MM, go to Config -> “Configure ports, Mode control, Audio, Other” then open the Hardware tab. 
  2. For the COM port which the USB/RS232 adapter is using, select the radio Elecraft K3, and then select (tick) the CW/Other box for that port. 
  3. Click the Set button for the COM port and then configure the port to match how it is set up on your K3 i.e. port speed (38400), Parity (N), data bits (8), stop bits (1), DTR/pin 4 (CW), RTS/pin 7 (always off), radio nr (1).  Deselect (untick) all 3 PTT options (VOX on the K3 does that) and Allow ext interrupts.  For completeness, select two radio protocol None, foot switch None and CW/PTT port addr 2F8 (these work for me but I’m not entirely sure what they do!) .
  4. End the N1MM configurator by clicking the OK button once for the Config ports panel and once more for the Configurator.  It will immediately try talking to the K3.  Hopefully, it will not give you an error message but will bring up the normal N1MM screen, now showing the frequency and mode from the rig (in the title area of the main data entry window).  Success!
  5. Now try it out: hit the F1 key to send a CQ message in CW – assuming you are running a CW contest in N1MM and it is talking to the K3 OK.   Hit the Escape key to interrupt the sending.  There are lots of things you can do to make N1MM send the correct serial number in the exchange, automatically send CQs on a loop etc. etc. – check the N1MM documentation for clues. 

Configure Logger32 to connect to the K3

  1. L32 K3 radio setupIn Logger32, go to Setup -> Radio -> Radio 1 configuration.
  2. Select the correct Com port, baudrate (38,400) , radio (Elecraft K3), databits (8), stopbits (1), parity (none).
  3. Set the polling interval to about 200mS (polls the radio 5 times a second) - more often if you like, less often on a slow PC.
  4. Check (tick) just two options: Use narrow CW filter and Radio changes frequency when Mode is changed.
  5. Click Apply. Logger32 will begin talking to the K3 and should identify the current frequency of VFO A (it ignores VFO B) in the title bar of the main log entry window. [Note: Logger32 doesn’t always show the frequency of my K3 - sometimes I have to QSY the K3 just a bit to get it to pick it up. I’m not sure why that is.]
  6. If you wish, confirm that Logger32’s CW sending function (click the Morse key icon to launch it) sends CW as it should (in the keyer setup dialogue, check Share radio serial port for CW and Slow typing).

Note: observant viewers may have noticed that I use Com 2 in N1MM but Com 4 in Logger32. The reason is that for everyday logging, I use LP Bridge to replicate the real K3 port (which is Com 2 on my PC) across a number of virtual Com ports for Logger32 (on Com 4) plus various other utilities such as MMVARI. I can’t get N1MM to work reliably with LP Bridge so for contests I shut down LP Bridge and connect N1MM directly to the K3. It’s one less thing to go wrong, and avoids any delays and glitches when keying the K3 from N1MM’s memories.

Useful K3 features

Triggering the K3’s voice memories from N1MM contest logger

If you have the neat little K3 DVR option installed, N1MM’s superb contest logger software can be configured to trigger the K3’s voice memories using the PC’s function keys to send the relevant K3 commands:

  1. In N1MM, open the SSB memory config screen (Config --> Change CW/SSB/Digital Message Buttons --> Change SSB Buttons).
  2. In the .WAV File column, instead of the file name of a .wav file on the PC, enter the appropriate K3 command string to play the relevant memory:

    N1MM SSB memory config

  3. The four “CATA1ASC” commands shown in this screenshot play the K3’s voice memories M1 through M4 using function keys F1 through F4 respectively. You can send other commands to the K3 in the same manner - check the K3 Programmers Guide for the available commands and parameters.
  4. Click OK to save the config.

Test it at this stage if you wish by hitting F1 to F4 in N1MM (assuming you have already recorded messages on the K3). Note: it’s best to put the K3 into TEST mode to avoid actually transmitting the messages on air until you are ready to work people!

Now configure the radio port to send PTT commands: this will allow you to interrupt the memory currently being sent with the PC’s ESCape key - dead handy if you press the play button just as someone comes back to you:

  1. Go to the port config (Config --> Configure Ports, Telnet Address, Other)
  2. Identify the COM port you use to control the K3 from N1MM and click the SET button for that port.

    N1MM port config

  3. Turn on “Radio PTT via command” by putting a checkmark in the box.

    N1MM PTT config

  4. Click OK to come out of the config menus.

If my instructions don’t work for you, try N6ML’s instructions instead.


“Instant CW split” macro

When I come across a juicy morsel of DX operating split, I use the following key macro to set up the typical “Up 1” CW split instantly, making use of the K3’s sub-receiver. It is configured on one of the K3’s front panel keys so a single tap on the button, plus a bit of time to tune around and find a good frequency to transmit in the pileup if he’s not listening exactly 1 kHz up, is all it takes. No messing around with the split button, turning on the subRX, resetting the VFOs etc. - it all happens automatically, quickly, correctly and reliably every time:

 1   2   3   4     5      6     7    8   9     10   -----------11-----------

  1. RT0 = Turn RIT off just in case it was set previously
  2. XT0 = Turn XIT off just in case it was set previously
  3. FR0 = Turn normal split mode off, just in case it was set previously
  4. DV0 = Turn diversity receive mode off, just in case it was set previously
  5. BW0100 = Set the filter bandwidth to 1 kHz to focus-in on the DX, cutting off most callers in the pile [you may prefer even narrower settings, such as BW0060, but I tend to reserve narrow filtering for the few times when I really need it. If you normally operate SSB, use a wider setting such as BW0180 or BW0200 or more, otherwise you won’t be able to copy the DX!]
  6. SWT13 = A>B [first time] i.e. copy the DX frequency from VFO A to VFO B
  7. SWT13 = A>B [again] i.e. copy the mode, filter settings etc. from VFO A to VFO B
  8. UP4 = Moves VFO A up by 1 kHz [note: 4 is a parameter not a frequency - see the programmers’ guide for other possible split values. “Up 1” is just a starting point that works for most CW DXers. SSBers usually split ”Up 5”, so use UP7 instead. Either way, be prepared to tune around for the best frequency on which to transmit]
  9. SB1 = Turn on the SubRX to listen to the DX, now he is on VFO B
  10. BW0280 = Open the filter on VFO A to 2.8kHz so I can listen to more of the pileup in the hope of finding someone working the DX
  11. MN111;MP002;MN255 = Listen to audio from VFO B in both ears with VFO A in my left ear only [MN111 is the code for the audio mix function; MP002 is a parameter; MN255 ends the code. The parameter options are MP000 = A B (great if you are able to concentrate on either ear) MP001 = A AB (giving VFO A priority over B by being in both ears)  MP002 = AB B (giving B priority) and MP003 = AB AB (both VFOs in both ears). Naturally, this command only works if the subRX is turned on!]
  12. Optional extra LKB$ = Lock VFO B to avoid me accidentally tuning away from the DX station by knocking the VFO B knob [I prefer not to lock the VFO so I can follow the DX around if he should QSY, without having to release the lock, but this means I must be careful not to knock the little knob]

Notice that I do not use the K3’s built-in split mode to operate split. I listen to the DX on VFO B and transmit on VFO A. Advantages of this ‘reverse split’ configuration:

  • QRQ QSK still works fine, whereas split operation disables QRQ mode.
  • I’m tuning around the pileup with the main VFO knob, leaving my little knob well alone.
  • I can use the CWT tuning indicator to zero-beat my transmitter more accurately on other callers.

I'm tempted also to turn on the attenuator to reduce the audio QRM from the pileup, using RA01; but meanwhile I simply use the AF/SUB knob (with the K3 configured for SUB AF = BALANCE) to reduce the volume of VFO A relative to B. [Arie PA3A proposed a command to reduce the audio from A or B by 6dB without having to fiddle with the mix settings and AF/SUB knob, so he can command it from N1MM during a contest, but for now the fiddling works for me. Others use external audio switching and mixing boxes to combine different rigs/receivers.]

By the way, Logger32’s “radio control panel” lets us send arbitrary commands to the K3 through the serial port. Logger32 also has the brains to recognize split-frequency DXcluster spots (such as when someone ‘helpfully’ spots some juicy DX with something similar to “up 2” or “QSX 14027” in the comment), sending the split-frequency macro to the K3 as it QSYs to the spot. But, as always, don’t forget to LISTEN FIRST and find the best place to transmit. Don’t be a cluster crab.


“Instant CW pileup” macro

The following macro is handy for me to start ‘listening up 1’ with a single button press, when I generate a CW pileup of my own:

  1     2    3   4   5   6   7   8   9     10      11    -----------12----------

  1. SWT13 = A>B [first time] copy the frequency from VFO A to VFO B
  2. SWT13 = A>B [again] copy the mode etc. from VFO A to VFO B
  3. UP4 = Move VFO A up by 1 kHz
  4. FT1 = Turn split on (SWH13 would do this too)
  5. DV0 = Turn diversity off
  6. SB1 = Turn on the SubRX to keep an ear on my TX frequency, while also listening to the pileup
  7. RT0 = Turn RIT off
  8. XT0 = Turn XIT off
  9. LK$1 = Lock VFO B, allowing me to tune through the pileup on VFO A without the risk of accidentally knocking my TX frequency on VFO B
  10. BW0270 = Open the filter on VFO A (the pileup) to 2.7kHz to catch callers who are not right on my announced split freq (I can always narrow the bandwidth on A using the width control if the pileup gets too big, but mostly I prefer to pick out individual callers ‘by ear’)
  11. BW$0050 = Narrow the filter on VFO B (my TX frequency) to 500Hz to avoid hearing split callers too close to me, while still listening for those who fail to split at all plus any kops who QRM my TX freq
  12. MN111;MP002;MN255 = Listen to the pile in both ears, plus my TX frequency in the right ear only


“Unsplit” macro

Here’s a key macro to clear any split, locks etc., resetting the K3 instantly to my default unsplit setup:

  1     2      3     4    5   6   7   8   9   10  ----------- 11 ----------

  1. SWT11 = Swap VFO A with VFO B [since I have usually been listening to DX on VFO B with the reverse split setup, and want to continue listening to the DX when unsplit]
  2. BW0270 = Set VFO A to 2.7kHz bandwidth, my preferred bandwidth for all modes
  3. SWT13 = A>B [first time] i.e. copy the DX frequency from VFO A to VFO B
  4. SWT13 = A>B [again] i.e. copy the mode, filter settings etc. from VFO A to VFO B
  5. FR0 = Turn off split
  6. SB0 = Turn off subreceiver
  7. RT0 = Turn off RIT
  8. XT0 = Turn off XIT
  9. LK0 = Unlock VFO A
  10. LK$0 = Unlock VFO B
  11. MN111;MP001;MN255; = Set the audio mix to A AB [so if I later turn on the sub-receiver, I will hear it only in my right ear]
  12. Optional extra DV1 = Turn on diversity mode - useful when I have a diversity antenna anyway!


Audio mix macros

These simple key macros set the audio mix without having to navigate the CONFIG menu options:

  • SB1;MN111;MP001;MN255; turns on the subreceiver and sets the audio to A AB (A priority)
  • SB1;MN111;MP002;MN255; turns on the subreceiver and sets the audio to AB B (B priority)

Turning off the subreceiver returns the rig to the normal A A setting, with ‘stereocode’ effects if AFX is on. This makes quite a difference over plain monophonic audio on CW. It’s cool. Try it! In the K3’s menu (tap the menu button), set AFX MD to dELAY 5 for the most pronounced effect.


Other K3 features and tips

If, like me, you use Logger32 with the K3 and if, also like me, you prefer to use the K3 in CW-REV mode rather than CW, there’s a simple workaround to get the K3 to stay in CW-REV when you click on a DXcluster spot - see my Logger32 page for details, also how to get Logger32’s DVK function to trigger the K3’s DVR memories.

The K3’s DVR memories work well on SSB and CW but I find the user interface confusing ... cue the helpful DVR operating instructions by KE7X.

Here's a tip for AFSK RTTY users on the K3. The tones transmitted by the PC should match the tones expected by the K3, particularly if you have the TX audio filters turned on (it’s a menu option ). If they don't (for example if you try to respond to a signal too high or too low in the audio frequency range), the PC audio will trip the VOX but little if any RF will emerge and the K3 sidetone/monitor will be quiet or silent. I discovered this when changing to a new sound card. I'm now using a second card to separate PC bleeps, MP3s, YouTube audio etc. from my pure RTTY tones. While playing with the settings, I discovered the K3’s PITCH setting in AFSK modes. The low tones (915Hz) sound nicer to my CW-tuned ear than the default high tones (2125Hz), so I set the K3 to 915. I neglected to change the MMTTY setting - largely because I tend to use "NET" in MMTTY to set the transmitted tones to match the received tones, which lets me 'tune' on RTTY just by clicking in the middle of RTTY sigs on the MMTTY waterfall (I hope my convoluted description makes sense!). With NET off, MMTTY defaults to high tones which the K3's line input evidently filters out (although the VOX presumably triggers on raw audio before the filter).

Having subsequently set the 915Hz tones in MMTTY, I saved the MMTTY profile to stop it reverting to the high tones every time MMTTY is re-started (same applies when using MMTTY within Logger32: set the tones then save the profile).

According to someone on the Elecraft reflector, the K3’s numerous birdies can be significantly reduced if not eliminated by carefully dressing the cables within the case, knocking out the remainder using the clever LO displacement function in firmware. With a quiet receiving location, birdies on the high bands are the most annoying so perhaps I should give that a try, next time I have the case open.


K3 REF CAL re-calibration

Re-calibrating the K3’s VFO frequency is easy if you can have a high quality frequency reference such as a GPS-trained Rubidium source, or can hear one of the standard frequency transmissions such as WWV or WWVH:

  1. Turn on your K3 and wait a good while (e.g. a couple of hours) for the rig’s internal temperatures to stabilize in your normal shack operating conditions. Don’t even bother trying this if your shack temperature fluctuates wildly while you are operating.
  2. Tune to your frequency reference in CW mode. You should hear a carrier at roughly the same pitch as your CW sidetone (if you are uncertain of that, hold the SPOT button to hear your sidetone and check its pitch). Pick the highest frequency reference you can receive a strong enough signal to discern its pitch clearly (e.g. 20MHz) as that accentuates any error compared to using lower frequencies (e.g. 10MHz).
  3. Hold the Mode-down button to switch to CW-REV mode on the other sideband. If the pitch changes, your VFO is off frequency. Switch back and forth between sidebands a few times to be sure you can hear the difference.
  4. Hold the MENU button to go into the main configuration options.
  5. Turn the small VFO B knob to find the REF CAL option and make yourself a little note of the current value - well the last 3 or 4 digits at least.
  6. Turn the VFO knob to adjust the REF CAL value up or down by a few Hz or tens of Hz - you should hear the pitch change a bit as you do so.
  7. Flick back and forth between CW and CW-REV to hear whether the pitch is the same. If the difference is greater than before step 5, you may have moved the VFO CAL the wrong way, so go back to the original value and shift it a bit the other way. [You may also have gone the right way but too far: don’t worry, you’ll get there in the end!]
  8. Repeat steps 5 and 6 repeatedly, making smaller moves of the VFO CAL as you get closer the point at which you can no longer hear any difference in pitch between CW and CW-REV.
  9. You’re done! Tap MENU to exit the menu.

If you are not good at discerning small differences in pitch by ear, or want to be even more accurate, use audio spectrum analysis software such as SpectrumLab (ideally using a fine resolution setting such as FFT input size of 16384) to compare the pitch more accurately between CW and CW-REV. WSJT-X also offers a frequency calibration mode. You should be able to get to within 2 Hz of the true value, with care down to within 1 Hz.

If you screw up completely, reset the REF CAL to the value you noted in step 5 and either give it another go or just “live with it”. Minor frequency errors really don’t matter at all in normal ham usage. I re-check my K3 every few months, and usually come up with the same REF CAL value of 49.379.781 (on one of my K3s - others differ). I only bother with this rigmarole at all because I want to report the actual frequencies of HF beacons as accurately as I can, partly so I can identify them later from the same information having tuned them in carefully using the K3’s CWT function.


K3 + Sennheiser headset

Santa brought me a fabulous Christmas present one year, a Sennheiser PC 230 headset . I have been a fan of Sennheiser headphones for about 25 years. I had been happily using a pair of Sennheiser PX 100 lightweight folding headphones to listen for several hours a day to my K3. The audio quality and comfort were excellent, while the open style means I could hear things happening around me, such as someone knocking at the door. The PC 230 basically adds an electret microphone on a little adjustable boom so I no longer need to use the old Kenwood handheld mic for my rare forays onto SSB. A switch in the boom turns the mic on as it swivels down into place. The mic has a noise-cancelling pickup on the outward side of the boom, and the headphones have a rotary volume control neatly built into the right earpad. Cool!

To make it work on the K3, I had to turn on the microphone bias (press ‘2’ when in the MIC menu option to toggle bias on/off) and adjust the mic gain and compression to suit. The mic seems to have plenty of gain: I have it set at just 6 on the low-gain setting (press ‘1’ in MIC to toggle high/low gain).

The PC 230 lead is comfortably long enough to stretch underneath the operating desk and plug into the K3’s rear panel phone and mic connectors, reducing the front panel clutter and clearing my desk a bit. I leave the front panel mic settings configured for the Heil headset that I prefer for contesting. The Heil has closed earmuffs and a restricted bandwidth mic insert, although I could achieve the same effect on a full-range mic using the K3’s TX equalizer settings, so perhaps it is time to retire the old Heil.


My K3 wish-list & bugs

The K3’s firmware is amazing in what it can do but inevitably there are a few little bugs and flaws. Here’s my current wish list:

  • There is a little firmware bug (acknowledged but unfixed by Elecraft) that stops CW-in-SSB working if I power-cycle the K3 in SSB mode, with QRQ configured on, on any band except 6m (!!). Until the bug is fixed, power-cycling with QRQ configured off restores CW-in-SSB;
  • For some reason, CW-in-SSB also does not work if I assert the PTT line or operate split;
  • I used to use a footswitch to hold the PTT closed during a CW over, mostly to stop my old valve amplifier dropping out between words. If I released the PTT footswith while sending CW (relying on VOX to continue holding the PTT) or even if I turned on the PTT while the rig was already sending on VOX, the K3 sometimes messed up the character being sent at that instant. PTT handling should really be a lower priority than CW sending ... [The workaround for this bug is to use QSK with a suitable amp such as the KPA500!];
  • Fast tuning is a pain: even with two speed control buttons (fine and rate) and using the clarifier as a fast-tune knob, it is awkward to get between, say, the 10m beacon sub-band and CW or SSB sections. “Ballistic tuning” was once mooted by Elecraft, meaning that the tune rate will increase with the rate of spin of the VFO knob/s, and would be nice. Meanwhile I am using the RIT/XIT encoder knob to move more quickly, and to set the VFO to round kHz values;
  • The V--> M button should be physically distinctive - I’ve coloured mine red with a marker pen until I learn not to overwrite a memory when I meant to recall it;
  • There is no ‘quick memo’ function like on the TS850, FT1000 and others. I found that a really useful way to store the current settings, whizz off to check something out, and return to where I left off. On the TS850, a single button-press was all it took, or I could tune between 5 quick memo stores using a knob [I’m now using M2 as a single temporary memory. Not quite as easy or flexible as a true quick memo function but better than nothing].

Other software defined radios are updated from time to time but users appear to have little say in what changes are made by the manufacturers. Elecraft claims to be very responsive to customers but I have to say that so far I have failed to persuade them to fix the three bugs in the top three bullets above.


Elecraft W2 wattmeter

I bought the W2 mostly to address a simple problem: I sometimes forget to change antennas after changing band and wanted a gizmo that would instantly lock out and so protect my old valve amplifier if the SWR was too high. The W2 does that, and has LED bargraphs displaying forward and reflected power. Fair enough.

It has a drawback, though, compared to big old Yaesu power meter I used to use. The Yaesu uses a traditional analogue meter which gives better resolution (though probably worse accuracy) than the W2. When tuning my old valve amp, the load and plate tuning is critical on some bands. The analogue meter is better to squeeze out the last few percent of efficiency.

The kit was easy to assemble and works well, within the limitations of the LED bargraph anyway. With hindsight, perhaps I should have invested in an LP-100A meter since its higher resolution LCD display would be better for tuning the LK550 amp.

The connection between pickup head and display box uses an Ethernet cable. It would be interesting to site the head remotely, at the far end of my long coax runs, in order to check how much power is being lost in the cables and connectors ... but the supplied cable is only a couple of meters long. A 30m Ethernet cable evidently introduces too much resistance, but looking at the circuit diagram, I see there are 1k resistors in most of the lines: I bet if I bridge them, it will work over the long cable. <To be continued ...!>

Having lost the original W2 programming cable, I had to make one up ...

W2 programming lead


Elecraft KPA500 amplifier

The KPA500 is a 500W “key down for 10 minutes” FET amplifier running at 60V with a built-in mains power supply. It uses fast electronic switching and hence gives totally silent and lightning quick QSK - no relays to click and wear out. It is a no-tune design with low pass filters selected automatically for each band (160 to 6m) using RF sensing or a connection from the transceiver - more on that below.

As with the K3, building the kit involves assembling a set of panels and strengtheners for the case and a few pre-constructed PCBs, the PA unit being the main one with its large heatsink. The kit instructions said nothing about which way to mount the fan and it had no markings to show which way it blows. In the end I put it with the label outside: it sucks air in through the top vents and blows it out of the rear of the amp, which is the way I like it, voiding into the space behind the shack desk rather than blowing in my face. It is nice and quiet, especially compared to the roar of 4 muffin fans inside my big old valve amp.

Aside from silent QSK, the size and weight of the KPA500 were big attractions for me as I plan to use it for DXpeditioning. It is the same size as the K3 so it will fit into a flight case and can be taken in the cabin of a plane as hand luggage. It weighs 12kg, about half of which is the toroidal transformer. If needs be, the transformer can be removed without too much trouble and carried separately in the hold.

QRQ QSK is a joy to use. Not only can I hear immediately when someone comes back to me, or QRMs me, or comes back to someone else, I can also turn the beam when CQing on CW to find the strong reflections that usually mean I’m getting out well in that direction. I can time my transmissions to get around the oh-so-helpful frequency kops and other lids on my frequency, and hear when my signal is going twice around the world!


K3/KPA500 data cable

I foolishly neglected to buy the Elecraft cable linking the K3 to the KPA500, thinking I could make one up from connectors in my junk box ... but nVGA cable de-pinnedot only did I have none of the 15-way 3-row D -sub VGA connectors, I couldn’t even find a source to buy them in NZ. Elecraft wanted a ridiculous US$70 to ship me the cable so instead I found a local supplier of VGA extension cables: cables marked “VESA DCC compliant ” have all 15 pins connected straight through with no gaps, no shorts and no cross-links to the shield. Sure enough, a VESA DCC VGA extender cable from an NZ supplier was correctly wired and, at 0.5m tip-to-tip, the perfect length provided the K3 and KPA500 are immediately adjacent on the desk (I later splashed out on a slightly longer cable). After checking the pin numbering (it’s embossed on the female connector), I carefully pulled out pins 1, 6, 7 and 8 from the male end with a pair of long nose pliers giving each pin a slight twist to extract it whole rather than just break it off.

The converted VESA extender cable works well: the K3 and KPA500 are slaved to the same band. Band changes can be made from either one. The K3’s output power can be set for two levels per band, namely about 23W drive if the amp is operating or some other level (e.g. 5 or 100W) when the amp is in standby. The K3 shows “KPA STANDBY” or “KPA OPERATE” and beeps once when the amp changes status, just in case I didn’t notice the amp’s OPER/STBY LED change.


KPA500 firmware updates

Mostly the KPA just sits there quietly doing its thing, as any well-behaved amp ought to do. It talks to the K3, follows me from band to band like an obedient puppy, ramps up its fan if it gets too warm, backs off the power or alerts me to a fault if I do something silly (such as transmitting on the wrong antenna). It delivers.

Elecraft occasionally updates the KPA’s firmware, far less often than the K3 since it is much less complex. Having not updated my KPA in well over a year, I forgot how to do it, so here are my notes as a reminder for next time:

  1. Check Elecraft’s KPA software page for anything new (the KPA firmware and KPA Utility programs were both updated since I last checked).
  2. If the Utility was updated, download the new version and install it first. If you aren’t sure, run the KPA utility on your PC and check the version number under Help -> About KPA utility .
  3. Hunt for a serial/USB adapter that works. Plug it in to the PC. Check which port it has chosen this time from Windows Device Manager (which is accessible using <Windows+Pause>) by unplugging and re-plugging it to see what changes. [It may pick a different USB port if you plug it in to a different USB port than when you last used it.]
  4. Plug the serial/USB thingy into the KPA500’s upper serial connector, and turn the KPA on (if it isn’t already on).
  5. Run KPA Utility.
  6. If KPA Utility doesn’t immediately give you a pop-up status message such as “KPA version 01 .23 RS-232 speed 38400 bit/s” (which means it is already talking to the KPA), select the appropriate com port to kick it into talking to the KPA. You can also click Test communications . Congratulations, your PC should now be talking to the KPA.
  7. Open the Firmware tab. The folder location should still be as you left it, if not find the directory where you store your KPA stuff (in my case, C:\Users\Gary\AppData\Roaming\Elecraft\KPA Firmware).
  8. Click Copy firmware files from Elecraft . This tells the utility to go to Elecraft’s FTP server to download the latest KPA firmware to the directory noted in the previous step. Wait for it to do its thing. It may give you a message about having found and downloaded something new.
  9. If there was something new, click Send firmware to KPA to update the KPA’s firmware. The KPA will click and put itself into MCUload mode, update its firmware, then click back to normal about a minute later.
  10. Play with the settings on the Operate tab if you like. You can remotely-control and monitor the KPA with these if it is just out of reach, or somewhere across the planet.
  11. Open the KPA configuration tab. Put something useful in the power-on banner, such as your callsign in case it gets stolen and recovered by the police (in the vain hope that someone will work out how to operate the ON button, realise that your callsign is a unique ID, and turn up at your door with the KPA in hand).
  12. Click Save KPA configuration to save its settings, just in case you ever need to re-load it and can’t be bothered to reconfigure it by hand.
  13. Close KPA Utility, unplug the USB-serial thingummy and hide it somewhere very secret to give yourself something ‘fun’ to do next time.
  14. Make yourself a nice cup of tea to celebrate and GET ON THE AIR.

Hawke’s Bay
North Island
New Zealand

39o 39’ South x 176o 37’ East

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260m ASL


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