Go Back   WorldwideDX Amateur Radio Forums > Amateur Radio Related > Product Reviews


Amateur Callsign Lookup
Enter Callsign:

Elecraft K3 Review

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 09-13-2010, 11:50 PM
iTrader: (11)
 
Join Date: Apr 2002
Posts: 8,114
Moleculo has disabled reputation
Default Elecraft K3 Review


About a month ago, I decided to purchase an Elecraft K3 kit, sight unseen. Actually, I had seen the rig at Dayton, but I hadn't given it much attention. After reading a few very technical reviews of the Elecraft K3 touting the technical specs and merits of this very interesting rig, as well as talking extensively to a long time K3 user (and field tester for Elecraft), I decided to take a chance on a rig I had never actually touched. If you pause to think about it for a minute, this is actually how most ham operators probably make purchase decisions that don't live near a major ham radio store of some type. Now that I have the rig in place, it's time for a long term review.

While you're researching the K3, you will undoubtedly come across the detailed technical Clifton Labs series of articles. They are excellent and should be read in detail if the technical specs are your thing. The articles can be found here: Elecraft K2 and K3 Transceivers. My purpose with this review is not to comment on Clifton's findings, but to give a more general functional and practical review that more ham operators can identify with. If you have any questions or opinions of your own, please feel free to ask or comment.

The Build

If you would like to follow along with the build process, I've put together detailed photos of the major steps here: http://www.worldwidedx.com/hf-bands-...oto-diary.html. To sum it up, the build process is fairly straight forward. It isn't something that you should be afraid to try and it will familiarize you with the major components should you decide to purchase upgrades later. An additional plus for building the kit yourself is that Elecraft occasionally comes out with updates that require you replace or modify various component boards. If you've already experienced the build process, disassembly and reassembly will be a snap. The primary issue that you need to be careful about with the build process is making sure that you're using all the proper length machine screws and washers at each step. I feel that there are a few places where Elecraft should take some simple steps to ensure that you're using the correct screw lengths, but they don't, and you've been warned.

Aesthetics

The K3 interfae can probably best be described as utilitarian but simplistically elegant. The LCD display is smaller than the higher end Icom, Yaesu, and Kenwood rigs, but larger than some of the more entry level rigs. While the display is small (the whole rig has a small footprint), it does a remarkably good job of showing you all of the important information at one time. The digital S meter, SWR meter, TX power, ALC, compression, VFO A & B, mode, antenna selection, and filter selection are all easily visible. Here is a pic of a typical display:



One of the reasons that the display is able to be smaller than other rigs is because the K3 does not make use of soft keys that change function depending on the screen. This type of user interface is typically found in the Icom rigs. The advantages of this approach are that learning the functions and usage of the various buttons and knobs is fairly easy; you don't have to remember any complex menuing system. However, since the K3 is truly a Software Defined Radio, the lack of soft keys might actually be limiting to the future growth potential for new features.

Most buttons have at least two functions, and some have three. The function printed on the button is the function that is activated by tapping the button, while the label printed below is activated by pressing and holding the button. If the button you're pressing activates a variable settings, VFO A or B will adjust the setting. When there are more than two adjustments necessary, Tapping the 1 or 2 button will activate the other toggle adjustments. It may sound a little complicated, but once you understand the operation, it really is easy to remember because it is consistent throughout all operations. Here are a couple of pics of the main front panel and the various functions:

Front left:


Center controls:


The center controls are examples of knobs with three functions. You toggle from the left side labeled function to the right side by pressing the knob quickly. You adjust the setting by rotating the dial and activate the third setting by pressing and holding the dial.

Right side:


Standard Interface Features

The K3 comes standard with a built in, isolated sound card interface. By plugging in a basic stereo 1/8" and another mono 1/8 cable to your computer you can easily use sound card modes without purchasing or building any type of external interface. Because the built in sound card interface is RF isolated, you don't have to worry about nasty ground loops causing ground hum problems. The RS232 is a standard serial interface used for rig control, memory programming, and firmware updates. The ACC port provides inputs and outputs that include band data, PTT, Transverter control, external ALC, and other functions. The other ports on the bottom of the rear are standard ports for a CW paddle, key, PTT, and amplifier keying. A pic of the rear standard interface is shown here:



The blank panel directly below the standard I/O panel is the location of the optional RX antenna input/output, transverter I/O, and IF Out that you would use with panadapters.

This left rear pic shows the two standard antenna ports (ANT 2 comes with the optional auto tuner) and the location where the optional sub receiver port and 2 meter port would be. The power adapter is a standard Anderson Power Pole adapter.



Now that I've covered the major physical attributes, the next topics will cover actually using the rig. More to come...


Reply With Quote
  #2  
Old 09-14-2010, 01:09 PM
iTrader: (11)
 
Join Date: Apr 2002
Posts: 8,114
Moleculo has disabled reputation
Default

The Filters

Anytime the merits of the K3's design are discussed, the conversation usually starts with the IF roofing filter architecture and DSP implementation. Unlike other high end HF rigs, the K3's 8.3Mhz IF is at very low frequency by comparison. For example, Icom's 7600 IF is at 64.455 Mhz. By lowering the first IF, Elecraft has enabled the K3 to accept much more narrow roofing filters than would otherwise be possible. This is nice because it gives you the capability of filtering out strong adjacent signals at very close spacing in various modes before they get past the IF and into the DSP filtering.

As a point of comparison, we can look at the Icom IC-7600, which is in the same price range as a fully configured 100 watt, 5 filter K3. The Icom 7600's narrowest roofing filter is 3khz. If you want a more narrow filter because of strong adjacent SSB, CW, or other digital mode signals, you adjust the DSP filter to make the filter however narrow is suitable for you. The problem with having only a 3khz roofing filter is that if there are stations within that passband with strong signals a number of problems arise that the DSP cannot overcome, including receiver desense or blocking. Having to rely on such a wide DSP range of filter adjustment also can introduce DSP related artifacts like ringing.

The K3, on the other hand allows you to have the rig automatically switch in more narrow roofing filters as you adjust the filter width. One of the first configurations you do after the build process is tell the rig which roofing filters you installed, and what modes they should be available for. Here is a screen shot of my rig's configuration:



You can see that I have both 2.1khz and 400hz roofing filters installed, which are much more narrow than is possible with the Icom 7600. When a very strong adjacent SSB signal is within the 2.8khz passband, narrowing the filter down to 2.1khz and a small shift the IF passband makes that adjacent station's signal not even enter the first IF of the rig!

My first experience with how powerful this design feature is came a few nights ago when I was having a casual scheduled QSO with another station on 40 meters SSB. There happened to be a contest going on, so we had to find an open spot on the band in between contesters so we could talk. Well, a local contester with an especially strong signal decided to shift his frequency right down on top of us to make us go away - there was no doubt that this was intentional. Initially, his signal was so strong that it started causing blocking in my receive, wiping out the other station I was talking to. Unfortunately for him, both of us were using K3's, so we just narrowed up the filter, shifted the IF slightly and kept talking. The K3 filter architecture made it seem like the other station wasn't even there. It's one thing to describe something like this, but until you've actually experienced in action, it's difficult to appreciate. Of course, having the capability to use this type of filtering at your fingertips is incredibly useful for CW and digital modes where a lot of signals are crammed into a small bandwidth.

An important thing to understand about how the filters are used in the K3 is that it uses the widest filter available for transmit, with the DSP adjusting the TX bandwidth as appropriate. That means if you plan on using FM for 10 meters or 2 meters, you need the 13kHz FM filter. If you only plan on using SSB, CW, and digital, you can stick with the 2.7khz or 2.8khz as the widest filter. If you want to do AM or ESSB, you should order the 6kHz AM filter.

Once you've told the rig what filters you have installed, you can either select them manually by pressing the XFIL button, or let the rig switch between them automatically by simply adjusting the passband width. Here is a short video I did that shows the filter automatically changing between the 3,4, and 5 filter as I change the passband. You can also hear the effect in action by listening to the PSK31 signals. As a side note, you can also see the PSK31's decode function in this video.


Reply With Quote
  #3  
Old 09-14-2010, 05:50 PM
Captain Kilowatt's Avatar
Professional Amateur
iTrader: (1)
 
Join Date: Apr 2005
Location: Nova Scotia,Canada
Posts: 10,573
Captain Kilowatt is on a distinguished road
Default

I must admit that I both laugh and shake my head about all this talk about "roofing filters" (new name for an old thing) and how good they are. In reality manufacturers had a good thing going years ago with IF filters and then took the cheap route by expecting AF DSP to be the wonder circuit of the new radios. After the idea of AF DSP was found to be a very poor replacement to actual front end or IF filters they introduced these roofing filters that have been greatly accepted. Those of us that have been in radio for a while now are just glad to have an old friend back. You cannot beat a REAL RF/IF filter for keeping crap out of your passband and I am glad to see them coming back to double and triple (even quad) conversion radios. It looks like Elecraft has a good thing going with actual hardware filters as well as software filters.
__________________
Marriage is like a deck of cards. In the beginning all you need is two hearts and a diamond. By the end you wish you had a club and a spade.

Reply With Quote
  #4  
Old 09-14-2010, 07:55 PM
jazzsinger's Avatar
Bullshit Buster
iTrader: (0)
 
Join Date: Jul 2008
Location: United Kingdom
Posts: 1,818
jazzsinger is on a distinguished road
Default

Quote:
Originally Posted by Captain Kilowatt View Post
I must admit that I both laugh and shake my head about all this talk about "roofing filters" (new name for an old thing) and how good they are. In reality manufacturers had a good thing going years ago with IF filters and then took the cheap route by expecting AF DSP to be the wonder circuit of the new radios. After the idea of AF DSP was found to be a very poor replacement to actual front end or IF filters they introduced these roofing filters that have been greatly accepted. Those of us that have been in radio for a while now are just glad to have an old friend back. You cannot beat a REAL RF/IF filter for keeping crap out of your passband and I am glad to see them coming back to double and triple (even quad) conversion radios. It looks like Elecraft has a good thing going with actual hardware filters as well as software filters.
its always amazed me why good RF/IF filters are optional extras especially on high end transceivers,in my opinion they are essential.i've never been a fan of audio dsp,it gives a very unnatural robotic/metallic sounding audio,i much prefer a high quality RF/IF filter.

I must say Mole that is one very fine looking radio and is very well laid out in comparison to most of the big three's off the shelf transceivers.The k3 isn't a radio i'm very familiar with,does it do general coverage transmit?
__________________
"IT WON'T BE EASIER TO SPREAD YOUR VERSION OF HOW SH*T TICKS"
BOB85-2010

Reply With Quote
  #5  
Old 09-14-2010, 08:50 PM
74IN's Avatar
Senior Member
iTrader: (4)
 
Join Date: Feb 2003
Location: Labia
Posts: 2,382
74IN is on a distinguished road
Default

Whoa, PSK31 text on the display?
__________________



Reply With Quote
  #6  
Old 09-14-2010, 08:57 PM
iTrader: (11)
 
Join Date: Apr 2002
Posts: 8,114
Moleculo has disabled reputation
Default

Other Receive functions

The K3 has a very interesting Noise Blanker implementation that has proven to be very effective in the brief time that I have used the rig. Unlike other rigs that I've used that just have a variable noise blanker on a linear scale of aggressiveness, the K3 implements both IF noise blanking and DSP noise blanking. When you press and hold the NB button, the configuration screen comes up which looks like this:



The large text is the DSP NB adjustment, and the smaller text below is the IF adjustments. The first number next to the "t" on the DSP adjustment shows the relative pulse integration time and the second number shows the blanking level. On the IF adjustment, the NAR/MED/WID refers to narrow, medium, and wide blanking pulse widths and the number next to that refers to the blanking level. If you adjust the NB too aggressive on either setting, the audio will become choppy, which is typical. They may be out there, but I don't know of any other rig that lets you have complete control of the NB at the IF and DSP stages. An additional feature is that the NB setting is saved on a per-band basis, although you can override that behavior in the Config menu.

How well the Noise Blanker works is actually a testament to Elecraft's commitment to continually improving the K3 through firmware and hardware updates that they make readily available to their customers. I have been told that the original versions of the NB were very crude and didn't work well at all. That is quite a contrast with what I see now. This example demonstrates the main point that so many of the Elecraft "fan club" users make: when you buy Elecraft, you are purchasing a product that will be supported with updates and improvements over the long haul.

Noise Reduction

The K3 implementation of Noise Reduction is also a little different than most other rigs on the market. The first difference is that the NR adjustment level is saved in the rig's memory on a per-mode basis. Other rigs just have a NR level setting and it stays the same as you move between bands. In the real world, we use different antennas on different bands and have various devices around us (especially in the city) that cause various types of noise to interfere with our receiver that are worse on some bands than others.

Most rigs have a continuous, linear adjustment for Noise Reduction that is accessible by either a knob on the rig or a setting through a menu. The K3, however does not use a continuous, variable adjustment. It uses a series of step levels indicated by a label that looks like: F2-1. As I understand it, the first number following the F indicates how aggressive the NR is, while the second number indicates the level. Once you read a figure that reads: F5-1, an indicator with a small M appears indicating a different algorithm is in affect, mixing between DSP processed and unprocessed signals. The manual recommends using settings below F5, but I find in my location, the F5-1 setting works awesome.

Even though the NR adjustment is a little foreign compared with what I am used to, I find that it really works incredibly well. I attempted to capture a video with audio that demonstrates its usage, but I don't think it does the rig justice.


Reply With Quote
  #7  
Old 09-14-2010, 10:23 PM
iTrader: (11)
 
Join Date: Apr 2002
Posts: 8,114
Moleculo has disabled reputation
Default

Quote:
The k3 isn't a radio i'm very familiar with,does it do general coverage transmit?
Yes it does, with some exceptions. I'll cover the extended TX/RX capabilities in an upcoming installment.

Quote:
Whoa, PSK31 text on the display?
It will also decode CW, AFSK A, FSK A, and RTTY.

Reply With Quote
  #8  
Old 09-15-2010, 02:50 AM
Nth QLD Australia
iTrader: (0)
 
Join Date: Aug 2010
Location: Innisfail, Nth QLD, Australia
Posts: 8
VK4BOF is on a distinguished road
Default

Your preaching to the converted here.
The Elecraft K3 rocks my world!
__________________
73 de

VK4BOF
Jeff Cochrane
Innisfail, Nth QLD, Australia
Proud owner of Elecraft K3 #4257

Reply With Quote
Reply

Bookmarks

Tags
elecraft k3
Worldwide Radio Forum


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
MAGNUM 257 HP Review Robb Export Radios 311 10-20-2013 10:22 AM
Site Staff product review guidelines Moleculo Announcements & Open Forum 5 06-08-2010 05:54 PM
MFJ-993 B IntelliTuner Review Robb Meters, Mics & Other Accessories 24 02-10-2010 03:36 PM
Elecraft 2T-Gen - 2 tone oscillator build / review Moleculo Product Reviews 1 02-09-2009 02:37 AM


All times are GMT -7. The time now is 11:42 AM.


Powered by vBulletin®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.0
Worldwide Radio Forum