An Inexpensive Case for the KX1

Always on the lookout for new cases to tote my crap around in, I found this little gem at a local Staples store for around $10.00. It's just big enough to hold my KX1, a set of iPod earphones, the KXPD1 paddle (in the top cover netting), and a DC cord with lighter plug, holding everything snugly with nothing rattling around.



Vaultz lists it on their web site as a Pencil Box. Staples, Office Depot and OfficeMax are listed as dealers but none have it on their web sites, and in fact the only place I found to order online only sells them in lots of 6 for around $50.00.

Elecraft K3: Waiting, waiting...

...and waiting some more. Elecraft began shipping the K3 in mid-November. Serial #117 was shipped on Nov. 27; it was ordered on May 1. I placed my order on May 4 via the Elecraft web site and sent a 50% deposit check the following day, yet as of today (Dec. 1) I have not heard anything from the Elecraft sales dept. regarding my balance due, much less the expected ship date. So I'm checking the email every day hoping to find the magic email from Aptos telling me my radios ready to go.

Meanwhile I have to endure such torture as this:



Oh, the agony...

Update 01/08/08
The nicest thing anyone has said to me all week:

Dear Paul,

Attached is a copy of your K3 invoice for your confirmation. Your order will be shipping within the next 7-10 days.

Assorted junk...

Fifty years later, Jimmy Mulligan still lives with his mother and has never been laid.

Antennas, etc...

I bought one of these antennas on eBay for $20, reasoning that it was cheap enough to take a chance, and if it works it would serve as a travel/portable/emergency HF antenna for my KX1 - and, short-term at least, as the main antenna at the house. The seller, Bell Imel Group LLC, says:

This system requires NO GROUND and NO COUNTERPOISE. It only requires a minimum of one support and it can be configured for vertical polarization, horizontal polarization and NVIS operations. It tunes from 40 meters to 10 meters using an internal tuner on your rig or an external tuner.

Sounds good to me.

It arrived by Priority Mail in about a week. Upon first inspection it looks like a 50 ft. length of zip cord with one of the twin-leads cut at the halfway point. It terminates in a BNC connector.

First test was to hang it from a hook off my deck, running it along the front of the house, around the corner and through the door into the shack. In this configuration the KX1 tunes it up fairly well on 20m (3.1 SWR) but SWR is pretty high (9.9) on 40m (as measured by the KXAT1, which may or may not be calibrated correctly..); I'm hoping both of these figures will improve if I get it up high and in the clear, and away from the side of the house. On receive, the antenna works quite well. And quiet - even with the plasma TV on there was less broadband noise than I typically encounter with a random wire or the Jeep-mounted verticals (Outbacker and mono-band hamsticks). So in all, it's $20 well spent.

The only question is: What exactly is it? A J-Pole ? A Zepp? Damned if I know. I can't find any similar antenna design on the web or in any antenna books in the shack. From what I can tell it doesn't seem to be cut for any particular frequency as it requires a tuner to match it to 50 ohms. But it appears to work.

Some links regarding end-fed wire antennas:

• eHam Review
• N2CX on End Fed Half Wave Antennas
• The End Fed Half Wavelength Antenna (AA5TB)

While in antenna mode I took some time to properly attach the TerraFlex mounting brackets on the Jeep, drilling through the transom and bolting them firmly to the body. While doing this I had a close look at the HF connector and found it to be pretty much shot. I originally salvaged this from a 3-magnet mount that was on my old SE-R; I guess I got my money's worth out of it, but it's time for something new - the High Sierra Sidekick is the #1 candidate to replace the Outbacker.

Until then, I bought a new 3/8-in-to-SO239 mounting stud and installed it along with a short grounding wire from the underside of the stud to one of the screws which hold the door latch thingy. Now I can tune the 40m hamstick to under 2:1 - without the ground wire the antenna was a basket case, reaching 50 ohm resistance down around 6.2 MHZ with an SWR dip a bit lower. I adjusted the whip for lowest SWR in the CW portion of the band. So now I have at least one antenna that loads up properly. The JST-245 has no problem matching it even up in the phone segment. Of course it's still about 8 ft. away from the plasma TV, so not much use until the living room is shut down for the night. Been too hot and sticky to do anything with the hamsticks for the other bands, but the Outbacker, once cleaned up, loads up nicely on all bands except for 10m. The JST-245 is getting some use now; might try some RTTY next chance I get.

With the mobile antennas out of the way, I relocated the end-fed wire antenna to the back of the house, running it out the bedroom window and along the side of the house - still not in the clear, but it works well enough for me to SWL and practice my CW at night with the KX1 before I fade. I'm still too chickenshit to actually attempt a QSO, though I'm finding myself on occasion able to copy CW without realizing that I'm copying it, a sure sign that it's starting to stick. I did some tuning during the IOTA contest this past weekend and was able to copy some of the higher-speed QSOs - but contest QSOs are relatively easy because they're predictable.

The KX1 has turned out to be a real pisser of a radio; despite crappy band conditions and RFI I've had lots of fun tuning around and getting to know all the menu-driven features to the point where I can operate the rig without the manual. I'm hearing a lot of stations in the midwest and south during my midnight tuning sessions, plus the occasional European.

Elecraft KX1: Building the KXAT1 Automatic Antenna Tuner

This was an easy job, taking but a few hours. Once again I am at a standstill regarding calibration until I get a dummy load and a resonant antenna, but I tried it out on the 40m hamstick and it seemed to handle a mismatch of around 9:1 without giving any error message or releasing any smoke.

I'm not sure what all the hand-wringing over winding toroids is about; after reading the Elecraft reflector all these months I was expecting this to be a difficult, painstaking process that would surely end in disaster. Not so, this went smoothly for me during both the KX1 and KXAT1 builds.

So now two of the three major components are done, only the 80m/30m kit left unbuilt. I will give that a go maybe next weekend. An end-fed dipole antenna is on the way, so I will hopefully have the chance to make first QSO soon. Meanwhile, I'm listening as much as can and my CW skills are steadily improving. Who knows, maybe I'll be contest-ready by the time CQWW rolls around...

Elecraft KX1: Assembly Parts II & III, Final Assembly and Initial Tests

The second part of the assembly process (receiver section) was completed over the course of two days - I spent a couple of hours on Wednesday night installing the resistors and inductors, and completed the section early Friday evening. I probably spent more time looking at the the inductors under a magnifying glass to make certain I was reading the color bands correctly (did I mention color blindness sucks?). Apparently I did OK, because all of the tests and check at the end of Part II were satisfactory and, upon firing the radio up with a DMM probe stuck in the BNC connector as an antenna, I was able to copy CW signals on both 40m and 20m bands!

Since it was still early, I decided to proceed with Part III, the transmitter section and final assembly. This all went smoothly and quickly, and by 2am I was finished mounting the board in the case and sticking the rubber feet on the bottom. I proudly present Elecraft KX1 S#1763:

I still need to perform the final transmitter tests once I get my hands on a dummy load (the Elecraft DL1, perhaps). For shits and giggles I attached my Diamond RH77 VHF/UHF rubber ducky and tuned around on Saturday night during the IARU HF contest and was able to copy a bunch of stations, though not well enough to hear both sides of any QSO. On Sunday I tested it briefly with the Datong AD-270 active antenna that has been in the attic in Closter since forever, that seemed to work though the receiver gain was still not what I hoped it would be - had to turn AF gain nearly full, and thus got lots of hiss.

This morning I tried it in the Jeep with a 40m hamstick and the Outbacker set for 20m. Both antennas are poorly tuned, probably because of the lack of adequate grounding on the mount. Not much to be heard on 40 other than the growls from the plasma TV which is about 10 ft. from the antenna. Also noted what seemed to be lower gain on 20m. But again, this may be more an indicator of how poor my antenna systems are than anything else; I had to use a PL-259-to-BNC adapter which is of questionable quality. More tests to follow...

Elecraft KX1: Assembly Part 1

So after 3 months, I decided it was time to melt solder.

The first step of assembly - the control circuitry - was completed in about 5 hours. This included about a half-hour of measuring all of the resistors with the DMM, taping them to the inside of the cardboard box, and penciling in their resistance values; color blindness sucks.

The Hakko 936-12 soldering station worked very well, but the Kester .020" solder I bought didn't flow - it just balled up on the end of the iron - because (I found out later) I bought 'No Flux' solder. I wondered why it was so cheap... I found some old, thicker Radio Shack solder that I had in the junk box and used it as carefully and sparingly as I could, mindful of numerous warnings about the hazards of using excessive amounts of solder. The PanaVise circuit board holder is the best thing since peanut butter, I can't believe I worked without one in the past.

The KX1 passed all tests at the end of Part 1 - all voltages were within spec, the unit powered up, the white LED lit, everything that was supposed to work seemed to work.

First Component

WW2PT Advanced Resistor Identification System (patent pending).

Instant Electronics Lab - Just Add Clutter.

Words of Wisdom

FCC's Riley Hollingsworth (K4ZDH) channels my sentiments precisely in his Dayton HamVention address.

To the Nets: Just because you have been on the same frequency for 75 years, that doesn't mean you own it. All frequencies are shared. If you vary your frequency, or even if you don't have a net one night, the radio world isn't going to end.

To repeater owners: Just because you are coordinated doesn't mean you own the frequency. Coordination is a recommendation, not a frequency assignment. It's your call sign on the repeater and it's your station and your responsibility ...just as if you had left the door open to your station at home. If there is abuse, lock the door. Don't ask us to be baby-sitters or hall monitors of your repeater. That's what control operators are for. Nobody asked you to start a repeater. If you shut it down tomorrow, what would happen? People would use OTHER repeaters!

To the contesters: be more courteous. You are responsible for the frequency you are operating on and realize that's true even when you operate split. All frequencies are shared.

To those who don't like contesters: lighten UP!! Contests are short lived. Use the WARC bands. Wash the car. Cut the grass. Learn from the contesters - and this applies to you Traffic net folks too - learn from the contesters. They pass information a lot faster and more efficiently than you do. Contesters are some of the best radio operators on planet Earth. If the contesters operated at the same pace as some of the emergency traffic nets, the contest would be over after the first few dozen signal strengths were exchanged!

To the widebanders: If you want to be a Broadcaster, apply for a broadcast license. Using extraordinarily wide bandwidth on crowded frequencies at peak operating time is rude, selfish and inconsiderate.

To the QRP'ers: Thank you, thank you, thank you for your vitality, inspiration, enthusiasm and for being BUILDERS again! I wish I could take your enthusiasm and spread it over all segments of Amateur radio. When I watch you folks, I see the excitement and magic of my first contact.

To those who don't like QRP'ers: Lighten UP. ANYONE can use a linear amplifier as a crutch.

To the rag chew nets: 4 or 5 people meeting on the same frequency every night for 50 years using 1200 watts to talk a few hundred miles when 100 watts would do just fine is not a net. It's an informal roundtable. It ain't going to hurt you either to vary your frequency or skip a night. And the so-called "net" on 75 that bills itself as an "Oasis of Amateur Radio": Give us all a break. You are an ordinary roundtable. And no net is an "Oasis of Amateur radio."

To those of you who don't like DXpeditions: Lighten UP! If a group of people want to spend a lot of money to go to a rock or sandbar in the ocean, live in a tent and swat flies and scorpions for a week and talk over Ham radio 24 hours a day, SO WHAT: LET'EM DO IT!!. DXpeditions, too, are short lived, and such operation must be important to SOMEONE. Scarborough Reef drew over 50,000 contacts didn't it. And weren't over half of them CW, by the way? Nobody would have even known about it had it not been published in popular radio magazines.

When I'm elected President my first act will be to appoint Hollingsworth as FCC Chairman.

Elecraft K3 Transceiver

The Mighty K3 - My next rig.

I've had many a jones for many a radio since my last acquisition, the JST-245, over 10 years ago. First it was the FT-1000MP Mk.V, then the IC-756PROIII. But I waited. When the FT-2000 was released and I was certain that would be the one when I rebuilt my shack at the Closter QTH. Then Ten Tec announced the Omni VII, and I was sure that was the rig for me.

I've always admired Ten Tec, especially their Argonaut series which I lusted for as a young future-ham, but I never owned any of their gear - I always went for the extra bells and whistles of similarly priced Japanese rigs in the 80's and 90's. I had spent some quality time with their RX-325 receiver when I worked at Gilfer and found it a curious but uninspiring radio, a bit goofy to operate but a solid radio for it's price. Their Omni VI and Paragon transceivers in the 90's always looked a bit too 'homebrew' for me, plus the Omni VI was ham-band only. But I started to take notice when Ten Tec turned out a series of superb DSP-based receivers and transceivers - the RX-340, Jupiter, Orion, and Orion II - all of these really seemed to suggest that Ten Tec was no longer a niche-market player. Thus when the Omni VII was announced I felt compelled to put my FT-2000 purchase on hold.

The first Omni VII transceivers started shipping in February 2007. The reviews I've seen on eHam are all overwhelming positive. Rob Sherwood's lab tests show key performance results which exceed Ten Tec's claimed specs. The Omni VII brochure shows a radio which clearly resembles the 756PROIII - large color LCD screen in the center, tuning dial to the right with keypad above it, but lacking the PROIII's analog S-meter. There is a band scope that appears to be displayed at all times, and unlike the real-time scope of the PROIII, it does periodic sweeps. Compared to the PROIII it finishes a close second in the KB2YAN test ("Always buy the one with more buttons!"). Lets face it, the PROIII is just about the coolest looking radio on the market (well, except for it's big brother, the 7800). But the big difference is in the bits - by all accounts Ten Tec 's DSP software is far superior to anything coming out of Japan, and since receiver performance is of primary importance to me this tends to tip the scale in favor of the Omni VII.

The Omni VII's base price (with auto-tuner) is $2850.00. There are a few Collins CW filter options (500 Hz and 300 Hz) at $99.00 each, a cooling fan for $39.95, and the remote encoder/keypad for $139.00. Total = $3226.95.

I was finally settled on the Omni VII and ready to order it, when out of the blue Elecraft announces a new horse in the race - the K3. Under development for three years, the K3 is a DSP-based radio with a base price of $1749.00 (for the 100W version, unassembled; a 10W model starts at $1399), and a load of different options that allows one to configure it specifically to one's own taste. A summary of the K3 features and performance from the Elecraft web site:

K3/100 and K3/10 models (the K3/10 can be upgraded very easily, internally, to a K3/100)

Basic K3 price ranges from $1399 to $1989 depending on whether you start with the 10-watt or 100-watt model, and whether you choose factory assembled or modular, no-soldering, kit (this is the subject of the next email).

Desktop/portable size: 4"H x 10"W x 10"D (10 x 25 x 25 cm) -- optimized for both home and travel use

All modes (SSB, CW, DATA, AM, FM, plus AM-sync receive, and built-in PSK31/TTY decoder)

High-dynamic range, down-conversion architecture, plus 32-bit I.F. DSP for software-defined capabilities (and lots of room for future expansion)

Optional subreceiver with *identical* performance to the main receiver, including a fully independent front end, its own set of roofing filters, its own DSP, and low-noise synthesizer; binaural or combined receiver audio

Up to five crystal roofing filters *per receiver*, with bandwidths as narrow as 200 Hz

Narrow ham-band filtering, plus optional general-coverage receive filters (can be added to either or both receivers)

Internal 100-W ATU option with two antenna jacks

100 W PA module includes two large fans, circuit breaker, full parameter monitoring

All signal sources phase-locked to common 49.380 MHz reference oscillator; 1 PPM TCXO option, firmware-corrected to better than 0.5 PPM

Built-in PSK31, RTTY, and CW decoding and display allows use of digital modes with or *without* a computer; use CW keyer paddle or attached computer for casual, two-way data QSOs

Advanced noise reduction; auto- and manual notch. Noise blanker included (both I.F. hardware pulse blanker and DSP noise blanking)

Easy-to-use DSP shift/width and locut/hicut controls with automatic crystal filter selection based on selected passband width (in real-time -- no filter calculation delays)

Dedicated CW/voice message buttons; optional digital voice recorder

100 general frequency memories with alphanumeric text labeling, plus 4 scratchpad memories per band

Full-custom, optimized, segmented LCD with two VFO displays, alphanumeric text, and dedicated filter passband graphic

Rich I/O set: stereo speaker outputs, fully isolated soundcard interface, dedicated RS-232 I/O (and optional USB adapter), receive antenna in/out jacks (for patching in RX filters, etc.), and both front- and rear-panel mic and headphone jacks

One-click PC firmware download program checks for updates automatically and quickly updates microcontroller and DSP firmware

As I was prepared to spend $4000+ for a loaded FT-2000, I decided to price out a fairly loaded K3 just for giggles. Here's how it looks:

• K3/100 Transceiver: $1749.00
  Basic 100W radio with single receiver.
  
  
• KAT3 Automatic Antenna Tuner: $259.00
  According to Elecraft it will handle 2:1 SWR at full power, but as much as a 20:1 mismatch at QRP levels. Expensive, but probably useful.
  
  
• KRX3 2nd RX Module: $539.00
  Gotta have this. Not just a scaled-down "dual-watch" receiver like that found in the 756PRROIII which shares circuitry with the main RX, but a true second receiver with its own DSP circuitry and filters, a la IC-7800 and Orion, making the K3 a serious contest/DX machine.
  
  
• KBPF3 Gen. Cov. RX Module: $99.00/ea (x 2 = $198.00)
  As explained by N6KR:
  

  "The basic radio, as well as the subreceiver, have a full array of ham-band-only filters at the front end. This is to ensure excellent performance in the ham bands. These filters are switched in by means of relays. The KBPF3 option is a small plug-in module that sits above the ham-band filters. It, too, has a number of filters switched in by relays. The difference is that these are wider filters, covering all of the area between the ham bands. But they share the same input/output path as the ham-band filters. When not selected, the GC filters have absolutely no effect on performance, thanks to a very careful layout that minimizes trace lengths. When you tune the radio well outside the ham bands, an appropriate GC filter is automatically selected by firmware."

  Need two of these, one for each receiver. Did I mention this thing has Synchronous AM Detection?
  
  
• KFL3A-2.8K 2.8 kHz, 8 pole filter: $120.00 (x 2 = $240.00)
  Pair of wide SSB filters, which work with the variable bandwidth control and act a roofing filters.
  
  
• KFL3A-400 400 Hz, 8 pole filter: $120.00 (x 2 = $240.00)
  Same deal as above. I chose 8-pole 400 Hz over 5-pole 500 Hz.
  
  
• KFL3A-6K 6 kHz, 8 pole filter: $120.00 (x 2 = $240.00)
  Need to have good roofing filters for SWBC use.
  
  
• KTCXO3-1 TCXO: $99.00
  High-stability crystal oscillator (1ppm f/w corr. to 0.5 ppm.). I'm sure I won't really need this, but what the hell - I'm already broke.
  

Total for this configuration is $3564.00, just a bit more than the Omni VII, and a whole lot less than a tricked-out FT-2000. For a radio that, on paper at least, looks to give the IC-7800 and FTDX-9000 a run for the money, it's a no-brainer. While it doesn't have the LCD and bandscope of the YaeCom rigs, Elecraft has stated that a panoramic display unit will be produced later this year.

Took me about 10 minutes to decide to take the plunge and order the K3 as equipped above.

People on the various forums are already complaining about the price, about the fact that it's "modular" assembly and not a full-blown soldering job to build it, about the fact that Elecraft has lost it's charm, and a plethora of other gripes. Give me a break! If you want to build a kit, buy a K2 (or K1 or KX1)! If you don't want to buy a $3500 radio, just buy the basic model - it will probably run circles around anything else in it's price class, though there will be a trade-off between features and performance. I simply love the fact that Elecraft lets you buy as much radio as you need or can afford. Shit, I'd even make the transmitter section optional; this thing would make a killer receiver for SWL's and fill a niche in a market that is void since the disappearance of JRC and Drake.

There's also been much talk on the Elecraft reflector regarding filters - whether the optional filters are needed or not. I decided to order the filters (400 Hz, 2.8 kHz and 6.0 kHz, one of each for main and sub receivers) to cover my basic needs (CW, SSB and AM). And there's room for two more on each receiver if I want, say, the 1.o kHz for RTTY and maybe another narrow SSB filter later on. One thing I've learned over the years is get your filter while they're available - if I didn't load up the JST-245 early on, I'd be out of luck if I wanted to do so now. WA6HHQ has a nice summation of the K3 filter philosophy on the Elecraft site which supports my choice of filters:

My personal real-world operating -basic- filter recommendations? In a nutshell:

SSB: 2.7 kHz or 2.8 kHz

CW/DATA: 400Hz or 500Hz (Narrower for Data if you prefer)

AM: 6 kHz (and for wider SSB TX, we can select which filter you TX through and limit SSB b/w in the K3's DSP)

So the trigger is pulled, the order placed, a 50% deposit check is in the mail ensuring me a first-run unit, and the wait is on - the K3 is scheduled to ship in July, by which time I will be comfortably (!) settled at the Closter QTH and back on the air.

It admittedly takes a leap of faith to commit kilobucks to what is essentially vaporware, but I am impressed and comforted by Elecraft's track record, and the attention paid to customer by the design team (Wayne N6KR, Eric WA6HHQ, and Lyle KK7P) on the Elecraft reflector. It would be remarkable if this radio does not live up to expectations. I don't necessarily feel like I'm rolling the dice here.

As for the Omni VII, I'm not sure that there won't be one in my shack in the future. I really like that radio, and were it not for the timing of the announcement of the K3 I might have ordered it already.

Elecraft KX1: Tech Musings & HW-9 Comparo

With the KX1 kit on it's way I've been reading up on it (in particular) and QRP rigs (in general) in order to get back up to speed with the whole radio-electro-voodoo thing. Following is the KX1 block diagram:


Now let's see if I can't figure out what makes this thing tick before I start building it...

KX1 Circuit Description
The KX1 manual has a fairly simple description of the signal path, excerpted below in italics, along with my notes, observations, opinions, and other lies. To better understand the KX1 I compare it to my last (and first!) QRP kit, the Heathkit HW-9, as they are very similar in spirit if not design.

Receiver: The receiver is a single-conversion superhet, using down-conversion to a low intermediate frequency (I.F.) of about 4.915 MHz. Down-conversion minimizes complexity and receive-chain noise, while the low I.F. allows adequate CW selectivity with a variable-passband, 3-pole crystal filter. The use of active mixers keeps current consumption low, compatible with portable operation.

The single-conversion system is common to the HW-9, and that's prety much where the similarities end. The HW-9 uses a bank of switched crystal-controlled HFO (high frequency oscillator) circuits, each producing a fixed signal which is then combined with a 5.9993 to 5.7495 MHz VFO signal at the 1st mixer (Q107, an MFE131 dual gate MOSFET) to produce a premix signal for the second mixer (U401, a double-balanced mixer) - i.e., for 80m, the crystal oscillator output is 18.330 MHz; 18.330 MHz minus 5.993 MHz = 12.3307 MHz premix signal. The desired RF signal is subtracted from the premix signal and filtered by the 8.830 crystal filter (FL301) to produce the fixed 8.83 MHz IF - for example, 12.3307 MHz minus 3.500 MHz = 8.3307 MHz.

The KX1 is obviously a much more modern design. It replaces all of the HW-9's HFO, VFO and 1st mixer circuitry with a single AD9834 DDS IC to synthesize the injection signal for a single mixer (an NE602). Elecraft says:

DDS VFO: The VFO is based on a low-power DDS (direct digital synthesis) IC. A crystal oscillator provides the reference signal for the DDS, ensuring excellent frequency stability over a wide temperature range. While a DDS-based VFO does not offer the same signal purity as an L-C VFO or PLL synthesizer, it is a good choice for a portable station that will most often be used by a single operator well removed from strong nearby stations. It is also extremely frequency-agile, allowing coverage of both ham bands and SWL bands. The unit chosen (AD9834) requires a minimum of components and draws only 5 to 8 milliamps. The DDS output is filtered by low-pass filter L4/L5/C50-52. In order to provide adequate roll-off of non-harmonic spurs about 14 MHz when operating at 40 meters, the filter's knee is set just above the 20-m band edge. Because of this, LSB receive mode on 20 meters is less sensitive; LSB on this band requires a mixer injection frequency of 4.9+14 = 18.9 MHz, which is significantly attenuated by the DDS filter.

I'm a bit confused about the signal purity comment as it pertains to PLL synthesizers - I always though a big advantage of DDS over PLL designs was the lack of phase noise, but maybe they speak of other issues. For certain, nothing beats a crystal-controlled VFO (the big selling point of the Ten-Tec Omni VI, as I recall). Nevertheless, the DDS advantage is obvious: a single chip in the KX1 virtually replaces the entire oscillator circuit board found in the HW-9, the sole purpose of which is simply to generate an injection signal for a double-balanced mixer.

Analog Devices says, "The AD9834 is a 75 MHz low power DDS device capable of producing high performance sine and triangular outputs. It also has an on-board comparator that allows a square wave to be produced for clock generation. Consuming only 20 mW of power at 3 V makes the AD9834 an ideal candidate for power-sensitive applications."



KX1 designer Wayne Burdick chose the AD9834 specifically because of it's frugality. " The most important design decision was to use a DDS VFO. This would eliminate a number of parts, including the transmit mixer and its crystal oscillator. While it wouldn't provide the high spurious-free dynamic range of an L-C VFO, it would be very stable over a wide temperature range, and also frequency-agile, allowing full coverage of 40, 30, and 20 meters as well as nearby SWL bands. Other designers had used DDS VFOs in QRP rigs with success, notably Dave Benson (NN1G) in his DSW series. But I'd been holding out for a DDS chip with much lower current drain. Luckily, one appeared: the Analog Devices AD9834, which draws just 5 to 8 mA."

Transmitter: On transmit, the DDS outputs the actual carrier frequency, so no transmit mixer stage is required. Q1, Q4 and Q5 form a 3-stage buffer for the DDS signal. Maximum power output from the final stage (Q6) is about 4 to 5 watts, depending on the supply voltage. Q7, in the receive band-pass filter, limits the signal voltage that can reach the receive mixer when the rig is in transmit mode.

A big departure from the HW-9, the KX1's transmitted signal is completely synthesized by the AD9834 chip. Exactly how this happens is a beyond my limited understanding at this time, except that the DDS is keyed by the MCU which (I assume) handles all of the built-in keyer functions, receiver muting, RIT, etc. The final amplifier of the KX1 is a single device, a 2SC2166 NPN transistor (Q6) in common-emitter configuration.

By comparison, the HW-9 transmitter and receiver sections share much of the same signal chain - the HFO, VFO and BFO sections, 1st and 2nd mixer, bandpass and low pass filters. In addition, the HW9 uses two devices (Q405/Q406, both MRF237 NPN-type power transistors).

Microcontroller: A low-power microcontroller (U1, MCU) is used to control the transceiver and handle user interface elements, such as the display and switches. The MCU communicates with the optional KXAT1 ATU on the VFWD/DATA line at about a 2 kHz data rate. U1 runs at just below 4 MHz to avoid band-edge spurs.

Not much I can add here, and there's no comparison to the HW9 here as it is a completely analog rig.

The KXAT1 provides SWR and power information for the KX1 display in TUNE mode. During normal keying, it provides an accurate indication of power output (1 bar per 0.5 watts). Without the ATU installed, the KX1 displays only a qualitative power output indication.

I built the optional manual antenna tuner and SWR bridge along with my HW-9 but don't think I ever used them. They are small units but certainly not as small as the KXAT1 internal board. It uses latching relays so there is no power drain (except while tuning), and according to the QST review it will match a random wire. It also remains in line during receive and is supposed to peak up incoming signals somewhat. I'm sure any sort of filtering will help since the KX1 has no front-end bandpass filters at all, just a low-pass filter.

Elecraft KX1: Pulling The Trigger

I've gone and done it now. I just ordered a KX1 QRP Transceiver kit, along with 30m/80m module and internal ATU. This will be my 2nd try at kit building; the first was my Heathkit HW-9 (along with matching tuner, SWR/wattmeter, and electronic keyer) back in 1985, which ended in near disaster - after completing assembly, the radio would not receive anything. I ended up sending it back to Benton Harbor, where they found a couple of cold solder joints and backwards-mounted components. I chalk that experience up to youth and ignorance (an oxymoron, to be sure). The KX1 sounds like an easy build, and there are a plethora of online resources to help me when (not if) I get stuck.

Why the KX1?
I've always been a fan of QRP operation even though I've rarely operated with less than 100 watts. I used to enjoy Adrian Weiss' QRP column in CQ Magazine back in the 70's, and still read the QRP construction projects in QST and CQ with interest and envy. My first ever HF QSO was made with the HW-9 back in 1987 on 40m CW, but once I got my TS-440S I don't think I ever used the HW-9 again. I bought an Yaesu FT-817 for a few years, made a few 5 watt mobile QSOs on 20m with it but mostly used it as a receiver before selling it on eBay (still kicking myself in the ass for that). Now I'm ready to give QRP another go. I considered another FT-817, but really feel like building something instead (and who wouldn't, after listening to all those SolderSmoke podcasts?). The Elecraft K2 would have been my first choice, it has so many more features (SSB, for one...); but it looks like it's a little more complex to build, and as my soldering iron has been cold for so many years I thought it best to try something a little easier for my grand return to kit building. More to follow...

Update 4/10: Talk about super super fast service - ordered on 4/9, received UPS shipping confirmation email on 4/10, scheduled for delivery on 4/17!

Links & Resources:

• Elecraft Web Site
• eHam: KX1 Reviews (and more)
• Yahoo! Groups: Elecraft
• W8KC's KX1 Photo Gallery
• N6KR: Evolution of the KX1

Big Plans

The time is near for some major station upgrades - not the least of which is a return to the original Closter QTH and it's vast antenna farm.* It's been about 10 years since I've acquired an new HF transceiver, so I've decided it's time for a modern DSP radio to complement the JST-245. The leading contenders are the Yaesu FT-2000 and Icom IC-756PROIII. I love the look of both of them, and they appear to be closely matched in performance based on reviews in QST and elsewhere. I asked KB2YAN which one I should buy; he said, "Which one has more buttons? Always buy the one with the most buttons." I guess it's going to be the Yaesu.

So now that I'm back on the radio bandwagon, I'm thinking about goals. Foremost of these is DXCC. I've already worked well over 100 countries, although the cards are somewhat lacking to make it official. Now it's my goal to do it again, starting from scratch.

* Not really.

No, Virginia, CW is NOT Dead.

On February 23, 2007, the Morse code requirement for amateur radio licensing will be gone. The debate over whether this should be done has been going on for years - opponents have claimed, correctly, that CW is an antiquated mode that no other radio service uses or requires, and that it is an unreasonable hurdle that keeps many otherwise dedicated and valuable operators out of the hobby at a time when we need them most, as other services seek to grab up amateur frequency allocations that are sparingly used; meanwhile, proponents of code testing cited tradition and warned of the floodgates opening, the HF bands tuning into CB radio, and.... well, damn it, I had to pay my dues and pass a code test, why shouldn't you?

I can appreciate both sides of the argument, but when I weigh the pros and cons, I find myself dancing on the grave of the code test. It's demise will not mean the end of CW on the ham bands; the only thing that will kill CW will be if hams choose to stop using the mode. I doubt this will happen, as CW is very popular among DXers and contesters.

The slippery slope argument is tenuous. It might have been a concern in the 70's during the CB craze, when CB radios were at the cutting edge of personal communications. But today the CB substitutes of choice are the internet and text messaging; ham radio won't capture the nitwit market because, 1.) It's expensive, and 2.) Even without the code test, getting licensed takes a good deal of effort. These are major obstacles to people who aren't serious about the hobby.

Amateur radio has always appealed to people who are fascinated with the science of radio, generally a brighter demographic than your typical chat room inhabitant. I can't see how these people will go through the whole licensing process, and the trouble and expense of building an amateur radio station, then suddenly devolve into a hoard of freaks shouting "Breaker Breaker!" into their echo mics on 20 meters.

So I welcome the FCC's decision to end the code requirement for licenses with HF privileges. I doubt most of the old curmudgeons that bitch and moan about it ever tune their radios off their 75m phone frequency, and probably fail to notice that the average age of US amateurs is quickly creeping up to the Geritol and Depends age bracket, let alone understand that that's a really bad thing. The hobby is in desperate need of a transfusion of new, younger blood, and telling kids that they need to learn CW, the telecommunications version of Aramaic, is the surest way to drive them back to their text messages and MySpace pages.

Do you like all those fancy modern HF rigs with spectrum scopes and DSP filters? Me too. Do you think companies like Kenwood, Icom and Yaesu will continue to devote R&D yen to continue producing these rigs while the market shrivels away? People on Social Security are not going to be buying many IC-7800's and FT-9000's, and sooner or later, if the number of hams dwindles, no one will be making these rigs.

So I say good riddance to the code test. And to celebrate it's death, I have downloaded every W1AW code practice MP3 file to my iPod so I can get my CW chops back.

• • • — • —

QRZ?

Doing the blog thing again, this time for my radio hobby. I will leave the existing WW2PT page alone for station info and links, and just use this blog for bloviating.