WW2PT/5

A quick update from W5-land... We arrived at our new QTH in Robinson, TX on August 29 and I quickly got most of the radios unboxed and set up the shack. My old desk was in pretty bad shape so a trip to Ikea was in order and yielded a nice corner desk with a riser platform I made from a cabinet door and some 8" stainless steel feet. The new backyard is about 50' x 50' but treeless - great for astronomy, not so much for dipoles and longwires; I think a ground-mounted vertical is a good possibility if I can keep it somewhat out of site of the management. Also a wire antenna of some sort in the attic as a second antenna though I doubt I can go longer than 40' or so.

Meanwhile, the same old story - SWLing with a random wire out the window, picking up every plasma TV and light dimmer in the neighborhood but occasionally pulling in some interesting stuff (interesting, that is, because it's far different than the northeast: no strong Euros on 75m in the evenings, for example, but many XEs. Just heard W6RJ booming in on 3799 kHz as I write this, but whoever he was working is buried in the noise.

Speaking of noise... all this computer shit is killing me! Cable modem, wireless router, printer, and computer PS all add up to a solid S9+ noise level. I'm sure this will be reduced when I have a coax-fed outdoor antenna but right now with a random wire running straight into the shack, I'm in RFI hell.

First thing I did after I got the internet hooked up was to upgrade the K3 to firmware version 02.38. Still no synchronous AM but a number of new features that were not there in the last version I loaded (1.75). Will need to download the updated manual to see what's what. In just a couple of days I've heard 3 different people on the 75 and 40 talking about their new K3s. Looks like the word is out...

I finally have the NRD-515 I bought last year unpacked and hooked up to the Kiwa MW Loop; when time permits I'll do some comparison tests to see how the 3.5 kHz Murata filter in this radio stacks up to the Kiwa 3.5 kHz module that I installed in my other '515.

The cable installer was fixated on my radios; he thought I was a broadcaster until I told him about ham radio. A PSK31 QSO was scrolling across the K3's display, so he asked about that as well as all the funny cards on the wall. Not sure if he's going to run out and get licensed but he was clearly interested in the technical stuff, especially the digital modes - we've come a long way since Morse code, I told him.

Where's WW2PT these days?

So I finally got my 2007 tax refund, the first in as long as I can remember, which was earmarked long in advance for all sorts of new ham equipment to complete my SO2R station.

Meet my new amplifier:
...my MicroHam MK2R+:
...my tribander:
...and my new power supply system:

See, now, this is the problem with having more than one hobby. Especially when each of those hobbies brings you one step closer to homelessness. It's not just a sickness, it's like suffering from several sicknesses at once and never knowing which one is going to flare up. If that refund had arrived a few weeks earlier when my brain was deep in radio fever it would have certainly been blown on all that stuff I want need for the shack; a few weeks later, maybe a Tele Vue NP127IS. Or a Taylor XXX-RS. Or model trains, or a lift kit for my Jeep, or a trip to Banff, or Yankees season tickets, or...

Someone stop me.

A Typical eHam Product Review

I don't own a K3, but I borrowed my friend's rig for a whole week; this is certainly long enough to make me an expert. I also stayed at a Holiday Inn Express last night. I didn't bother to read the K3's manual because I had a looming deadline for submitting this eHam review; and besides, reading the manual would have taken me forever because I'm functionally illiterate.

Here are a few of the defects I found in the K3 through my extensive, expert testing.

1. The AGC doesn't handle S9+30dB signals very well when I run full RF Gain. Also, the audio distorts and the speaker starts getting all crackly when I run full AF Gain. I thought about turning down both the RF and AF Gain but that makes no sense to me - that would be like driving a car without having the accelerator pressed to the floor all the time, and who drives like that? In fact, I really don't know why Elecraft would waste limited front panel space on the RF and AF Gain controls, no one uses them. This is just one example of Elecraft's flawed design concept. If they were smart they would have added adjustments to tailor the AGC slope, threshold, hold and decay rate to one's liking - but then again, that would probably require reading a manual, and who has time for that?

2. The noise floor is not as good as my Pro3. I always have to use the NR of the K3, while I never use the NR on my Pro3. The fact that the K3 with NR ultimately delivers a better signal than the Pro3 is capable of, with or without NR, is irrelevant since no one uses NR anyway - it's as stupid a feature as the RF and AF Gain controls.

3. The K3 transmitter really sucks. First of all, the third-order IMD products are so bad that it wipes out QSOs 3 kHz away. Second, the transmit audio is so narrow that it is impossible for me to generate hi-fi voice signals with 6 kHz bandwidth, which really limits my ability to wipe out QSOs 3 kHz away. In addition, the compressor distorts my transmit audio unless it is set it to a proper level which doesn't distort my transmit audio. This is ridiculous - what good is compression if you can't run it flat-out like the RF and AF Gain?

4. The Noise Blanker on the receiver adds distortion to the received audio unless it is set to a proper level which doesn't add distortion to the received audio. I just can't seem to come to grips with the complexity of this system.

5. The K3 is too small for contesting. Everyone knows that Big Guns need Big Radios, because they show up much better in the photos we take of our shack and post all over the web. Instead of having a front panel littered with buttons and knobs and meters and a large LCD display (which really impresses my non-ham friends, btw), important parameters are buried in menus, which is very frustrating when I need to re-calibrate my PA heatsink temperature or change the date format from US to EU in the middle of a 100 QSO-per-hour run.

6. The clock needs to be set manually. Elecraft really missed the boat on this one. They could have included a GPS receiver to keep accurate time, or at the very least included an atomic cesium-133 oscillator option.

7. I find the lack of 10 antenna jacks stupid, especially since the radio has 10 bands. It's bizarre that you have to buy an optional accessory to get a separate receive antenna and a second antenna jack. This is as ridiculous saying the narrow CW filter, transverter output, 100W power amplifier, antenna tuner, general coverage BPF, and digital voice recorder are options on a radio. Everyone should pay for these features whether they require them or not.

8. I ordered the 1ppm TCXO and was shocked - shocked! - to learn it only provides 1ppm accuracy.

9. I find using the VFO knob very tiring, the arm bail is way too high and with the bail arm down its way too low. The K3 needs some kind of variable height adjustment, preferably a digital control with a dedicated knob on the front panel. This should be easily accomplished through a firmware update, but Elecraft is too busy wasting time on less important things like finishing the subreceiver design and improving filtering and AGC performance.

If you asked me if you should buy this radio today, I would say no. I would wait until all the options, mods, bug fixes, and pixie dust are released. There appears to be a unwritten code of silence on making criticisms of Elecraft, the fact that I am criticizing Elecraft notwithstanding - that's only because I've managed to outmaneuver the Aptos hit squad that has been following me for the past week. There's no telling when I might end up sleeping with the fishes because of my unwillingness to take my medication and get treatment for my K3 Derangement Syndrome, but until then I will continue to speak truth in the face of the K3 Kool-Aid Drinkers.

I rate the K3 between 0.0 stars and probably 0.5 stars. If all the stuff they promised gets delivered and the all the bugs get fixed its probably a 1 star radio. On the other hand, if Icom executes a hostile takeover of Elecraft and the K3 is re-released as-is with an Icom label, it will probably be a 5 star radio.

73 DE ANONYMOUS

p.s.: I almost forgot the most important thing: The markings on the front panel are difficult to read when I turn off all of the lights in my shack and operate in the dark, which I need to do if want to chase DX while under surveillance of the Aptos hit squad.

Elecraft K3 Hardware Changes: Ham Radio's Worst Kept "Secret"

The K3 kerfuffle du jour on the Elecraft reflector is the "scary" proposition that Elecraft is making "secret" hardware changes to correct problems with the original design, and that by not sharing this information with K3 owners and prospective buyers, Elecraft's honesty is in question. Oy vey...

The argument that Elecraft is "secretive" regarding their updates and changes is belied simply by the fact that we're discussing the updates and changes at all. If anything, Elecraft and their field testers talk too much about these things - otherwise, how would anyone know about such changes in the first place? So much for the "secrecy" theory.

Elecraft should be commended for the frankness, openness and accessibility to their customers; for quickly responding to customer requests; for their willingness to improve the K3 with new features (for example, CW-to-PSK, and improvements to the filtering and noise reduction programming) that go above and beyond the published specs of the radio); and for (up to now) offering these improvements to the end user free of charge. Yet some still complain and excoriate because they are being kept out of a loop that they are not, in fact, in. It is not my business (nor anyone else's) what goes on inside the design shop at Elecraft. The only reason we know as much as we do is that Wayne, Eric, Lyle, and others choose to share such things with us; they are not obligated to do so.

Most other manufacturers would say nothing at all and either make changes unannounced, or simply say, "Don't like the AGC [or QSK, or filtering, or third-order IMD, or whatever]? Deal with it - that's the way it is. Maybe we'll fix it in the next model." As for adding previously unadvertised features free of charge as Elecraft continues to do with the K3, consider this: when I purchased the original Icom IC-706, it had coverage from HF through 2m. When Icom added the 70cm band to the '706 my upgrade path was simple: Sell the '706 and buy a '706mkII. Was Icom being "dishonest"? Of course not - I got what I paid for when I bought the original '706. A free or inexpensive upgrade path would have been nice, but by no means was Icom required to offer one.

Now let's pause for another boring JRC allegory...

WWJD? (What Would JRC Do?)
When JRC first released the NRD-535D receiver, it had a Murata CLF-D8 filter in the WIDE position, the BWC (variable bandwidth control) only worked in SSB modes and only with the INTER filter (2.2 kHz), and the RS-232C command set was lacking several useful commands (though it performed exactly as advertised).

It soon became apparent that the CLF-D8 filter was a poor choice - it was as wide as a barn door and did little to reject adjacent interference on the SWBC bands for which it was primarily intended. After much consideration JRC decided to offer free filter replacements for early NRD-535 owners and a box of CLF-D6S filters (the same as used in the NRD-525) was promptly sent to me at JRC-NY. I did my best to spread the word through the dealers and hobby grapevine (as it existed back then before the internets) that people could either have a filter mailed to them for self-installation or they could send me their radio (or just their IF Filter circuit board) and I'd happily swap it for them free of charge. There were no accusations of "secrecy" because we didn't notify owners that the CLF-D8 sucked before we devised the solution to the problem or keep them informed with progress reports; nor was JRC's character questioned because we did not prostrate ourselves before the marketplace and beg forgiveness for making a poor filter choice. People were happy - their original filter performed as promised, but a better filter was offered free of charge. Who wouldn't be happy?

We also started to receive a lot of requests from software developers for additional commands to improve the way the '535 interfaced with computers for remote control. Almost every useful suggestion was implemented, resulting in a series of firmware upgrades which necessitated the replacement of two EEPROM ICs, one of which was buried deep inside the front panel assembly - not as easy an upgrade as hooking a K3 up to a computer and running a utility app! Once again, these upgrades were offered for free, even though the original firmware worked exactly as specified. Some people took advantage of the offer, many who did not use computer control (or used software that did not utilize the new commands) chose not to do the upgrade. In any case, people were happy - it was nice to see a manufacturer pay attention to the wants and needs of its end-users. (Does this remind you of any current American manufacturer? Perhaps one located in Aptos, CA? Think hard...)

Later on, we started receiving question about why the BWC was disabled in the AM mode and not used with the WIDE filter. I, too, thought this was a good idea. The factory was persuaded to modify the BWC design to make it work with the WIDE filter and in all modes; this was done through a hardware change (the crystal filter on the BWC circuit board was replaced) and modification to the radio's firmware. All future production runs would incorporate the new BWC features, and again an upgrade was offered to early NRD-535 D owners. However, this time there was a nominal charge for the upgrade kit ($129.95, as I recall) because it was not a bug fix, but rather an improvement to the original design. I don't recall too many complaints about how unfair it was to charge early owners for the same features that later purchasers enjoyed for free. The fact was, JRC (once again) listened to it's customer base and improved an already excellent product, and (once again), people were happy. But this was back in a time before no good deed went unpunished.

My point is, hardware and software changes are a normal part of production. No product is perfect, so it is a good thing to take customer feedback and fix things that need fixing, and if possible add things that can be added to an existing design. JRC understood this over 15 years ago just as Elecraft understands it now. Many other companies could care less, as long as the product is "good enough" to meet the published specs. The K3's transmit 3rd Order IMD of -27dB as measured in the QST test currently puts it in the same league as the Icom IC-746PRO and Kenwood TS-480; that is not "poor" as some have suggested but "average" performance and unless I'm very wrong falls completely within Elecraft's claimed specifications for the K3 as well as FCC spectral purity requirements. Elecraft could easily just leave it alone and be content to offer a rig with a superlative receiver but only an average transmitter, and they'd still be considered to be acting ethically and honestly; instead they've pledged to improve the TX side of things and offer a solution to early purchasers. I applaud them.

We now return to our regularly scheduled rant...

As an early adopter of the K3 I fully accept the fact that I am one of the test pilots of a complex piece of equipment, produced by a pioneering and evolving company in a way that is diametrically opposite the standard business model of the Big Three of JA-land. I considered this fact carefully when I sent in my deposit check to get one of the first production run. I could have waited for all the bugs to be shaken out of the K3, or I could have purchased a different radio with a more proven track record. In the end I chose to be part of the K3 bug-shaking process.

The moral of the story is, when you pre-order a version 1.0 product as complex and specialized as the K3, any expectation that it will work 100% as advertised right out of the starting gate is both unrealistic and unreasonable. On the other hand, it is perfectly reasonable to expect problems that pop up after the initial release of the K3 to be addressed in incremental updates (1.1, 1.2, 1.3, etc.); that seems to be the path Elecraft is on and nothing that they have done so far suggests otherwise.* Furthermore, if new features or functionality not originally specified or promised in the 1.0 version are added to later versions, Elecraft has every right to charge those who wish to implement those new features a reasonable fee, just as they have every right not to offer any such improvements at all. As someone else pointed out, how many Orion I's have a color LCD display?

* In fact, the official response from Elecraft to the specific question of transmitter spectral purity raised by the ARRL's lab test is pretty much what anyone familiar with Elecraft would expect: "We're looking into this already. Any improvement we make in firmware (or hardware, for that matter) will immediately be made available to all K3 owners." Who could ask for more? (Don't answer - we know who they are...)

Contrast Elecraft to the auto industry: I've received manufacturer recall notices for just about every car I've ever owned, each telling me that my car has a bug and I should bring it in to have it fixed. The manufacturers did not issue a series of prior reports informing me that they think there might be a bug, nor did they provide me with regular updates from their engineering departments letting me know what they were doing about it. A CEO of an automobile company is not going to be active in the owner's groups responding to individual questions and complaints. Instead, when a problem is confirmed and a solution is found, owners are notified and offered a remedy. If I buy a completely new model car when it is first introduced, I understand that I'll be much more likely to receive recall notices for it than if I wait a couple of model-years. This would be no different for any other type of hi-tech, non-disposable product; in recent years I've had to perform upgrades - both software and hardware - to fix bugs in countless computers and software applications, not to mention my iPod, my Celestron NexStar 8 GPS telescope, my Line 6 POD, many other amateur radio products, and God knows what else. This situation is by no means unique to the K3, and no other amateur radio product's upgrade path in my experience has been as smooth and painless as the K3's.

As Elecraft grows I fully expect them to learn from their K3 experiences and clam up a bit more about what is going on behind the magic curtain, as it will soon be impossible to respond to every gripe from every customer as they have so nobly done in the past. This will fundamentally change the character of the company, but it is an inevitable side effect of market growth. Like Apple, they will soon have to move out of the garage and start behaving like a "real" company - and I don't say "real" like it's a good thing; I like Elecraft just the way they are! Before the K3 there were a relatively small number of Elecraft users and the company enjoyed an almost exclusive, club-like following; now the K3 will likely push Elecraft to a new level in the industry and the "family" feel that Elecrafters now enjoy (and that I only recently became aware and part of) will by necessity have to give way to more mainstream business practices - including real secrecy, not the kind they are imagined by some to have now. My advice to the bitchers and moaners is: Enjoy it while it lasts.

Shortwave Listening With The K3

I would love to see the K3 receive the attention it deserves from the too-often ignored hardcore shortwave and mediumwave DXers and believe that with a few minor software tweaks the K3 could fill a huge void in the high-performance communications receiver market since it has been all but abandoned by major manufacturers.

Twenty years ago when I first started out in the radio business there were a good number of new desktop shortwave receivers to choose from including the Yaesu FRG-8800 ($639.95), Icom IC-R71A ($799,95), Kenwood R-5000 ($859.95), JRC NRD-525 ($1189.95), not to mention many used late-model receivers such as the JRC NRD-515, Drake R7, Yaesu FRG-7700 and Icom IC-R70. With sadness I've watched as radios like these have been slowly disappearing from the market, replaced by small portable radios aimed at the broader consumer market while serious hobbyists have fewer and fewer choices other than prohibitively expensive mil-com HF receivers, or amateur radio transceivers which more often than not perform awfully in the AM mode.

With the K3, I see hope; a basic 10W K3 costs only $1600 (or $1400 if self-assembled), less than the soon-to-be discontinued NRD-545 is currently selling for, and even with only the stock 2.7 kHz roofing filter the K3 would likely run circles around the '545 not to mention most of the classic receivers mentioned above. However, it will take a little fine-tuning by Elecraft for it to realize its potential as a top-notch SWL receiver.

AM Mode Filtering: There was talk on the Elecraft reflector a while back about the way the filtering works in the AM mode, specifically the 3 kHz maximum "audio" bandwidth. From an SWL's perspective, this makes no sense; it is counter-intuitive and non-standard compared to all other high-end communications receivers (I'll use the NRD-535D as a reference, since I'm most familiar with JRC equipment). With the '535, the filtering in AM mode works like one would expect; no matter which filter is selected, when the passband shift (PBS) control is centered the filter passband is centered on the carrier frequency and shifting the passband shifts tha actual i.f. passband, not the audio passband. So if a 2.4 kHz filter is used, it will pass 1.2 kHz of each sideband when PBS is centered. Offsetting the PBS 1.5 kHz to the right, for example, will move the entire filter passband to pass only the upper sideband while rejecting the lower sideband. This is useful to the SWBC DXer in cases where there is a strong signal 5 kHz below a weaker station that I'm trying to receive and the lower sideband suffers from adjacent channel QRM but the upper sideband is clear. And vice versa, if the interfering signal is 5 kHz above, tweaking the PBS to the left passes the lower sideband while rejecting the upper sideband and the QRM.

I'm not sure what actually happens in the same scenario when using the K3. If I set the filter width to 2.4 kHz and shift the passband to the right, it seems to work as expected - audio frequency response gets higher; but when the passband is shifted to the left, frequency response gets lower, which indicates that the filter passband is either not centered on the carrier, or it is split similar to the way it works in RTTY mode, and passes equal slices of both passbands. Whatever the case, the way it currently works is at odds with what is expected by a true SW or MW broadcast DXer.

Synchronous Detection: There is also the unanswered question as to whether the K3's forthcoming AM Synch mode will allow independent sideband selection. With synchronous AM detection, the ability to select sidebands independently is pretty much mandatory, otherwise the synchronous mode is useless on all but the strong, clear signals which frankly sound just fine without synchronous detection. The NRD-535 selects AM-USB and AM-LSB with the ECSS (exalted carrier selectable sideband) button. Most other receivers that have this feature work similarly. The Sony ICF-2010 does it a little differently - it lets you select sideband by adjusting the main tuning dial up or down slightly, and a little LED indicates which sideband is selected. The Drake R8, by comparison, does not directly allow selectable sideband; its synch mode was DSB, and although you could move the passband shift it isn't as effective as the JRC and Sony systems which totally reject the unwanted sideband.

Joe, W4TV, gets it; in one of his reflector postings on AM filtering he pretty much describes how the JRC ECSS system works in principle (the exception being that JRC doesn't do it with DSP):

Given the DSP demodulation in the K3, it's a shame that there isn't an "offset" option to do "vestigial sideband" demodulation (offset the AM filter to the upper sideband or lower sideband) and demodulate carrier and one sideband for better fidelity.

I'm not sure if Joe is talking about syncing the carrier and replacing it with an internally generated one, but that is what a good synchronous ECSS system does in a nutshell. Without selectable sideband capability, synchronous AM detection is like tits on a bull.

SWL Mode: Another easy software mod that would be welcome for people who wish to use the K3 solely for SWL purposes would be to include a setting to disable the transmitter, similar to the TX TEST mode but without requiring it to be set each time the radio is turned on. This can be done by at least making the TX TEST mode persistent so that the K3 would remember it was in test mode when it was last powered up. Preferably there would be an additional CONFIG menu parameter that would put the radio into SWL mode in which the TX indicator will be turned off (not flashing like in Test mode); if the PTT line is keyed while in SWL mode the K3 would display a message like "SWL MD" and there will be no RF output - basically extending the out-of-band transmitter disability to K3's the entire frequency coverage while in SWL mode.

And that's it - just modify the firmware code and send a K3 off to Larry Magne for testing! The rest will be history.

Specs, Lab Tests, and Other Myths

Rob Sherwood's K3 test results have been published. Key strong-signal performance specs include:

• 100 kHz Blocking: 140 dB
• Ultimate Rejection: 105 dB
• Wide-Spaced (20 kHz) Dynamic Range: 104 dB
• Narrow-Spaced (2 kHz) Dynamic Range: 101 dB

All is well in Elecraft-land as the K3 takes the prize over the Flex 5000, IC-7800, Orion II and, well, everything else Sherwood has tested, at least in the Narrow DR category. Predictably many early K3 owners are pumping fists and doing the Happy Dance, and I'm sure there are going to be IC-7800s and Orions on eBay in the coming weeks.

But what does it all really mean? I don't have any overwhelming sense of validation for choosing wisely, nor do I intend to take Rob's receiver tests as liberty to taunt the unfortunate fools who bought the FT-2000 about how much better my K3 is, because frankly they're not unfortunate fools and I'd love to have an FT-2000. Performance is certainly important - no one wants a complete dog - but my ears can't tell the difference between 105 dB dynamic range and 95 dB. If you think you can, then you probably can hear the difference between Monster Cable and Radio Shack speaker wire, too. Bless your heart.

Myriad reasons I picked the K3 without hesitation have already been mentioned in my previous posts. Sure, the claimed (but at that time, unconfirmed) performance was a factor, but equally important were Elecraft's reputation, the K3's feature set, its elegant design, portability, price, the ability to configure it to my needs with just the options I require - all these things are much more subjective than the K3's now-documented performance advantage over all the megabuck rigs. I spent years toying with the idea of a new HF rig (MK V, Pro2, Pro3, FT2K, Omni VII, K2) but never pulled the trigger; when the K3 was announced and I sent in a deposit check within a week. It was preference, not performance, that sold me - the K3 simply has everything I want in a radio at this time.

Having a large radio with a beautiful display might be an important enough preference for some people that they would gladly sacrifice the 21 dB dynamic range advantage (and $6,000+ price difference) of the K3 for the IC-7800. Honestly, if I could afford the '7800, I'm pretty sure there would be one on my desk right now. Maybe an FTDX-9000MP, too. But they would certainly be in addition to - not instead of - the K3.

I'm of the opinion that test specs are useful for marketing purposes, splitting hairs, winning bets, and endowing nitwits with bragging rights, but in most cases specs tell only half (or less) of the story. I'd rather have a radio that has an 85dB dynamic range but is a joy to use, for example, than one with 105 dB DR but also crappy audio quality, drill-down menus for important settings, and a loud fan. A radio is much, much more than the sum of its specs. What makes the Elecraft K3 special is that it delivers on both fronts: performance and usability. Or, as they say on the Elecraft reflector, it's got mojo.

K3 vs. JST-245: The Road To Victory

With the addition of a stereo line splitter to feed K3 audio into two separate channels on the Multi-RX, it is now far easier to compare the two rigs. The following observations refer to SSB mode only; testing in CW and data modes to come as time allows.

Audio Quality: The most obvious thing is, the K3's audio is much more crisp than that of the JST-245. By "crisp" I mean it has a bit more high frequency response, while the '245 has more punch at the low frequency end. Which is better is more a matter of preference than science. My ears generally find the weakest signals more easily readable with the K3, while signals S9 or better tend to have a more natural tone with the '245. But the differences are subtle, neither radio sounds dramatically better than the other when using a common audio system (in this case, the Multi-RX feeding a pair of small Sony speakers left over from my home theater surround sound installation, as well as a pair of JRC ST-3 communications headphones). The K3's stereo audio effects (AFX) settings can tremendously improve the quality of reception and reduce listening fatigue, and works equally well with speakers and headphones; the AFX feature gives the K3 a slight edge.

Noise Reduction: Most notable is the DSP Noise Reduction (NR). Even at it's lowest setting, the NR removes so much background hash with the push of a single magic button that I find myself turning it on and off just to come to grips with the fact that it actually works. There are several NR settings selectable by holding the NR button and dialing in the level. Lyle Johnson KK7P, Elecraft's DSP genius, says:

NR is more properly Signal Enhancement rather than Noise Reduction. The distinction is subtle but important if you wish to understand how it works and how to best apply it. If ti were noise reduction, the implication is that it passes everything until it figures out what is more likely to be noise, which it then attempts to suppress. Since it is signal enhancement, it tends to pass nothing until it figures out that which is more likely signal, which it then attempts to pass.

With this understanding there is one more concept I must explain: correlation. This is the degree to which a signal is similar to itself; conversely, it can be used to figure out how noise is dis-similar to itself (more random). This is the basis on which NR works.

In the current implementation of the K3, we have four (4) basic NR filters. These are displayed as F1..F4. F1 is the gentlest, F4 the most aggressive. Recalling that the filters tend to suppress everything until they can sort out what is probably a signal, there is some time delay involved in their application. Further, especially with voice signals, some components of the signal may not be recognized as well as others. THis gives rise to distortion.

So, we added a second field to the NR. This is the -1..-4 which specifies a certain amount of "bleed through" of the original signal. This reduces the apparent distortion and delay, but limits the ultimate S/N improvement. -1 provides the least distortion but limits the S/N improvement on weak to moderate signals to about 6 dB. -4 provides no "mixing" whatsoever and can result in dramatic S/N improvements, but at a cost of slight time delays and increased distortion.

NR is not appropriate for very weak signals, so a -1 or -2 is best if you wish to hear them.

Having said all this, the correct way to use the NR is to listen and adjust it for the best compromise between noise reduction and distortion. Everyone is different in this regard. Some tolerate noise better than others, while some don't tolerate distortion very well at all.

I live in a quiet location, and use NR1-2 as my most common setting. This is low in distortion, allows me to hear weak signals, and shows no apparent delay as I tune through the bands. On the rare occasions when things get noisy here, I crank it to higher values.

Noise Blanker: The K3 Noise Blanker (NB) is also a masterpiece - between the separate IF and DSP blanker settings I've been able to remove all sorts of crap that would otherwise make it impossible to hear any but the big gun signals. It's as simple as this: When I hear any sort of electrical noise, I first crank the DSP NB up to see if it has any effect. If not, I try the IF DSP. Usually one or the other does the trick, I haven't found any noise that requires both at the same time. The '245 NB is useless by comparison; if it works at all it must be against a very specific type of impulse noise that I've never encountered, because I've never found it to be of any use at all (unless distorting a desired signal is of use to anyone).

Notch Filter: With the '245 I almost always use the manual notch filter as a mid-cut to tailor the receive audio to my liking. I find this technique to be a bit more effective with the '245 than the K3 as the latter takes an awful lot of dial turning to adjust the notch range from 200 Hz to 3.92kHz in 20 Hz steps. Also, the K3 notch width is much sharper than the '245 so the effect is more subtle. Of course the K3 has built-in graphic equalization for the purpose of shaping the audio response, so this issue is pretty much moot and leaves the notch filter to be used for its intended purpose - to remove heterodyne interference. To this end, the K3's Auto Notch is superb. The manual says it will, in some cases, remove multiple carriers although I've yet to find a situation that will confirm this. The '245 does not have an auto notch function, but it has Notch Tracking which will offset the manually adjusted notch filter when the VFO is tuned slightly; this is useful but not nearly as effective as a fully automatic system. Notch depth is adequate on both rigs.

Ergonomics: Both of these radios are a joy to use. The '245 has a solid feel and a heavy, balanced main VFO knob that spins like a top. All of it's buttons have a nice positive 'click' when pushed, and the smaller knobs and controls feel good and not overly 'plastic'. And the color LCD! - it's about the finest looking display of it's generation and, in my opinion, better than anything even today short of the newer Icom color TFT displays of the IC-7800, IC-7700, etc. Because JRC took the time and effort to find out what amateur radio operators really wanted and where things were supposed to go on the front panel, all of the most commonly used controls are assigned to individual buttons or knobs with very few alternate functions or hidden menus to toggle through; outstanding ergonomics was a chief goal during the JST-245 design review, especially after the JST-135 got raked over the coals by Dave Newkirk in his QST review (and deservedly so). So although I may be biased as a member of aforementioned JST-245 design review team, I find the JST-245 to be a more enjoyable radio to sit in front of and operate.

The K3, however, is no slouch. Elecraft had different design criteria, one of which was to make the K3 compact and easily transportable. Neither of these adjectives can be applied to the '245, therefore JRC had a whole lot more front panel real estate to work with than did Elecraft. Consequently many of the K3's controls are doubled up, several often-accessed settings are menu-driven, and some things which take a single button push with the '245 take two or more with the K3. But by and large I think Elecraft got it right, the K3 has just the right amount of compromise between keeping the size of the radio down, making it attractive to the field user and people with limited space, and including all the high-performance features demanded by discriminating users such as contesters and DXers. So while I may have to toggle through different modes to set the K3 instead of pressing a single button, it's not a big deal to me. The K3's buttons have a soft feel to them which reminds me of the Drake R8 receiver's front panel buttons. While the main tuning dial does not have the same flywheel feel of the JRC it still spins nicely. The main liquid crystal display is very sharp and has a wide range of backlighting levels (including OFF), though it must be viewed at a fairly straight-ahead angle. All in all, from a usability perspective, the K3 is a nicely designed little rig.

The one area in which I find the K3 to be deficient is in its selection of memory channels - unlike the '245 which has a dedicated Memory Channel knob that lets the user dial through channels one by one, the K3 has a more convoluted process of pressing the M>V button, dialing up the memory channel with the VFO knob - without being able to hear what's going on at that channel's particular frequency! - then pressing M>V again to set the rig to the stored frequency, mode and other parameters. If I could change one thing with the K3 it would be to let me hear what's on each channel as I dial through the memories, before I hit the M>VFO button. This should be an easy firmware fix.

And the winner is...: In the tweakability department the K3 has a few bells and whistles that are missing (or ineffective) in the '245. In practice I find that I am able to get similar reception with both rigs by using each radio's tools to maximize the desired signal and minimize the junk. I am still amazed at how well the JST-245 holds up to the latest and greatest in DSP technology, and it is such a pleasure to use. Therefore I've abandoned any thoughts of selling the '245 to finance the acquisition of a second K3; it is simply too good a rig to let go of.

That said, the K3 is clearly the future of HF transceivers, and it looks to be a pretty bright future at that. While the above observations are subjective and based narrowly on SSB reception under less than perfect antenna and propagation conditions I think it's pretty clear that the K3 is a gem of a rig. Of course many of the design elements that on paper put the K3 in the league of the mega-buck rigs from JA-land do not come into play with my limited antenna system - for example, I rarely see a signal stronger than S9+10dB, and have yet to find two such signals close together as in a contest situation, therefore the benefit of the narrow roofing filters and strong front-end performance remain untested by me in any real way. In any case, others (ARRL, Sherwood*, etc.) will confirm or deny Elecraft's published dynamic range and IP3 specs soon enough, so I'll leave it to the pros to do the scientific evaluations.

If held at gunpoint and told to choose one of these two radios, subjectively, emotionally, and based solely upon my ears, fingers and eyes... it would have to be the K3. But barely.

* Update 09-Feb-08: Serendipitously, Rob Sherwood has released some of his K3 test results which were promptly passed on to the Elecraft reflector by Wayne Burdick:

Rob Sherwood, NC0B, an independent and well-known receiver performance specialist, has completed his K3 receiver tests. We're pleased with the results, which will place the K3 at the top of his comparison chart.

Rob will be updating his web site in a few days. For now, I'll just mention a couple of his numbers (with his permission).

Elecraft K3, S/N 00149, 20 meters, preamp off:

Dynamic Range 20 kHz 104 dB
Dynamic Range 5 kHz 102
Dynamic Range 2 kHz 101*

* with 200 Hz 5-pole filter

Blocking above noise floor at 100 kHz spacing, AGC On: 140 dB
Phase noise (normalized) at 10 kHz spacing: 138 dBc/Hz

Rob performs some tests differently that we (and the ARRL) do, but in general we're all in close agreement. Note that the unit under test had only Elecraft 5-pole filters. Our tests show the 8-pole filters to be as good or better, and we sent some of them to Rob to test when he gets a chance.

73,
Wayne
N6KR

Back in business...

The K3 is in place, the Multi-RX is back in action, the MFJ-267 watt meter/dummy load finally arrived, the antennas still suck...

With the playing field level - both rigs hooked up to the same antenna and speakers - I can do some fair and honest comparisons between the K3 and the JST-245. I must still fine-tune the system a bit - an adapter to split left and right channel audio from the K3 speaker output is first on the list, and I think I can do something with an antenna that is somewhat temporary yet still effective (and quiet) and will tide me over until I get to the new QTH later this spring.

K3 Testing Pt. III

A week on, and the K3 continues to impress.

RS232 Interface: Got the computer interface working, using a Keyspan USB Serial adapter. MacLogger DX has actual K3 support. Running Windows 2000 via Paralells on the MacBook Pro, allows me to finally try HamRadioDeluxe by HB9DRV - a very cool program which will take a bit of poking around on my part before coming to grips with all the features. HRD, however, does not support the full K3 command set, instead uses the K2 subset which is backwards compatible with the K3.

Firmware Updates: With the serial port tested and working I downloaded the Mac OS X version of the K3 Utility software. A couple of clicks later, my K3 has the latest firmware revisions installed (MCU: 1.66, DSP: 1.52). Kudos to the design team for such a smooth and elegant update process. Oh, the thought of all those times I had to disassemble the NRD-535's front panel to change EEPROMs... [shudder].

Headphones: I am not 100% satisfied with the audio quality of the Heil Proset headphones, and the frequency response of the Audio-Technica ATH-M3X stereo phones that I sometimes use is a little too broad for radio communications. Then I remembered that I got a pair of JRC ST-3 phones with my recent NRD-515 acquisition so gave them a try. Awesome... except that they are monophonic and will not work with the stereo AFX settings. But the gears are turning - can I rewire the ST-3 for stereo? Can I add a boom mic? Hmm...

RX Antenna: The Outbacker antenna is awful. Maybe that's because it's old and decrepit, maybe it's the installation, maybe it just never worked as well as I thought it did. In any case, it really sucks, no signals appear to be more than S5-S7 on the 40m band and even worse when tuning 80m, so I ran that Bell Imel eBay special to the RX Ant In and now see strong signals in excess of S9+10dB on all of the low bands which gives me a better idea of how the K3 will work when I finally get it hooked into a real antenna. Of course the noise level is also increased to S9 or so. This gives the NR and NB a good workout, and I'm pleased with the amount of noise reduction I'm able to dial in - not always enough to completely eliminate the noise but almost always sufficient to make a thoroughly unintelligible signal copyable. I also discovered that with antenna connected to RX ANT IN and second radio connected to RX ANT OUT, simultaneous reception on both radios is possible* making receiver comparisons easy.

Birdies: There are some nasty birdies on 80m band, especially down in the CW portion. They are heard with no antenna connected and vary in pitch when I adjust the filter controls, so I suspect they are being generated by either the DSP board or the MCU. I will go back into the rig and check that all screws are tight when I install the 100W PA.** Haven't noticed any loud birdies on other bands.

Miscellany: Decoded my first PSK31 signal. Figured out how to set and recall memory channels. Ditto CW messages. No further sign of PL1 ERR.

* Update 08-Feb-08: I've discovered that while reception on both radios is indeed simultaneous, when the RX ANT is selected the K3 will receive from the antenna connected to the RX ANT IN jack, but the second rig connected to RX ANT OUT will receive from the K3's main antenna (ANT 1 or ANT 2).

** Update 10-Feb-08: KPA3 is now installed, and although I didn't find anything loose that may have caused the birdies, after the PA was bolted in and the rig reassembled the birdies on 80m seem to have disappeared!

Day 2 With K3

Saturday yielded some interesting observations.

PL1 ERR?: I flipped the K3 on in the afternoon and let in run for about 6 hours to give it a chance to burn in. Later, around 8:30pm I meandered down to the dungeon to give it a spin. When switching to 40m I got a "PL1 ERR" message on the display. Hmm. Switched to other bands, no error; it occurred only on 40m. After looking up the error in the manual (PLL voltage out of range) I did another VCO calibration and the error went away. Have to keep an eye on that to see if it recurs.

RTTY Decode: The BARTG RTTY Contest is running this weekend so there are lots of digital signals on the air. Getting the K3 to decode and display standard Baudot RTTY was a snap. The CWT tuning meter and split filtering for mark and space tones are both great features. Decoded almost everything with a moderately strong signal or better.

CW: In a word: Stunning. So much better than other radios I've used. Auto Spot works extremely well, and text decode is a useful but not so much that it can (or should) be used as a crutch. The French REF CW contest was on and I heard several F stations calling CQ TEST, plus several domestic QSOs. Even at the narrowest bandwidths the copy was perfect with no filter ringing or distortion as with the JST-245, just a clean DC note. The Dual Pass Band filter mode is great. This may very well be the rig that finally gets me into CW in a big way.

Ergonomics: It's a small radio, but not cramped with buttons and knobs. Everything seems to be where it needs to be for easy access. I never particularly liked radios that made me step through modes and bands (especially when wearing headphones!) but that is just a personal preference thing, I'm sure I will get used to it. All of the knobs and buttons feel good to the touch, not overly cheap like some of the YaeComWood radios I've used over the years. The LCD is very crisp and looks great at all brightness levels. Fairly light weight, but not so much that it goes sliding across the desk when I push buttons. All in all, a very solid radio.

JST-245 Comparo: I ran a cable from K3 RX Ant Out jack to the JST-245 for receiver comparison. Under this night's particular conditions (shitty antenna, internal speakers, dead bands) I was surprised to find the two radios to be very close on SSB. When not using the K3 noise reduction the JST-245 delivered a little more punch on the weakest signals, but when the NR is kicked in the K3 really stepped up. On stronger voice signals, I really preferred the sound coming out of the JST-245 - it just seemed to have a little more punch to it. This could be attributable to the different speakers, or perhaps to the fact that I haven't tweaked the K3's RX EQ to a setting I like. Whatever, this fight will have to continue once I get the Multi-RX set up again so the two radios can be compared through a common AF system. On CW... well, I never liked the JST-245 in that mode so it's not a fair fight. So for Round One, I'd score it K3 10, JST 9 - very close but the DSP giving a slight edge to the K3.

Receiver-wise, the K3 has pretty much met my expectations relative to the hype it has received. I was at first a little surprised that the JST-245 compared as well as it did, but then I remember how much better that radio is over all the other analog (and several DSP) HF rigs I've used so maybe it's not so surprising after all, just further testament to how great the JST-245 really is. It will be interesting to see how the two radios compare when better antennas deliver stronger signals under more favorable band conditions. Meanwhile, I need to complete the installation of the 100W PA, set the rig up for use with my Heil Proset and MH2 mics, and wait patiently for the rest of the options to ship.

Elecraft K3 #216 Passes Smoke Test!

It's aliiiiiive!!!!!!

Assembly took about 6 hours, including a painstaking inventory count of every #4 inside-tooth lock washer and whatnot. The 100W PA is still in the box, that will have to wait until I get a dummy load and can do the TX tests called for in the manual. No major problems with assembly, just a few minor things like the four connectors that mate the front panel assembly to the main RF board taking a lot of fidgeting before snapping together.

When I confirmed and updated my order with Lisa at Elecraft I left the General Coverage BPF off my list, so I've asked her to send one to me as soon as possible.

First impressions:

• DSP Noise Reduction and AFX (binaural audio and delay effects) make weak signals jump out of the background noise.
• Filtering very steep and with good rejection - tune 3 kHz away from S9+ SWBC carrier on 40m, dial bandwidth down to 2.5 kHz, and it vanishes without a hint of it ever being there.
• Ergonomics excellent, though I have to get used to the Vol/RF Gain knobs on the left side of the main tuning dial. I keep reaching to the right instinctively after years of using JRC and Kenwood transceivers.
  

Some photos during assembly...

Woohoo!!!

The nicest thing anyone has said to me so far this year:

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

Finally, after 8 months and 4 days! I've changed my order slightly, sticking with the stock 2.7 kHz (5 pole) filters instead of the 2.8 kHz (8 pole) options, and adding 2.1 kHz (8 pole) filters to go along with the 6 kHz and 400 Hz filters (one of each in main and sub receivers). Also ordered: the KVX3 transverter output in order to take full advantage of the K3's myriad antenna possibilities; the KDVR3 digital voice recorder, as I intend to do some contesting with the new rig; and an MH2 hand mic just in case I ever need it. I will still have one open filter position in each receiver, but otherwise this radio is fully loaded.

Total price for all this fun stuff is $3,603.00 - this for a radio which by all early accounts will hold its own with (if not surpass) the Orion II ($4,500) and IC-7800 ($10,500).