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Elecraft K4D First Impressions

I've had the Elecraft K4D for a week so it's time to report on first impressions.


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First, the display and user interface is stunning. The interaction with the rig is a very thoughtful blend of touch screen and traditional buttons and knobs. The HDMI interface allows you to run an external display with several configurations controlling how it is used. In the picture above, I'm showing the Panadapter for both VFO A and B in a split screen, while displaying only a wider VFO A panadapter on the rig. I will post more pics with other configurations in the coming weeks as I have a new LCD on order which I will dedicate to the rig.

I purchased an Icom 7300 when they first came out, curious about how well the touch screen panadapter would work. Having used both, I can say without a doubt that the Elecraft implementation is superior in every way possible. First, the most important thing is the way signals just really pop on the screen on the K4 using even just the default display settings. For lack of a better explanation, I always felt that the Icom 7300 panadapter was "muddy" compared to PC based implementations. Not so with the K4. The span can be adjusted all the way out to 368 Khz or as tight as 5Khz. The "AUTO" reference level just works and I haven't found a reason to turn AUTO off yet. The waterfall has a NB setting that you can set to AUTO or adjust as desired. Lastly, the touch screen is intelligent enough to usually "snap to" the waterfall station you're trying to listen to. It really works well.

There are a couple of extra features that are pretty useful. For example, you can freeze the screen, which is helpful if you want to take a screen shot, like this:
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That's right, there is a screen capture feature that will write to the USB device you've inserted into the front port. If you touch the top left part of the screen where the S Meter exists, it will change to a "Mini Pan", zoomed in on the frequency you're monitoring (shown above).

I could write a small book about the UX, but I'll save some of that detail for later. After getting over my initial fascination with the display, it was time to dial around and listen for a while. Without changing any parameter related to AGC (which you can tailor significantly), I tuned to 40m SSB, turned on the Attenuator to kill some of the ambient noise (attenuator range is from 3db to 21db in 3db increments) adjusted the RF Gain slightly and dialed around to listen to various stations and was absolutely impressed by the way even weak stations popped out. This thing is a joy to listen to.

While listening to a net on 40m, there is the typical range of very strong, very weak, and every signal strength in between. The K4 has a feature called "RX Dynamic Range Optimization" which is normally turned on. Here's the excerpt from the manual that describes this feature:

"The RX Dyn. Range Optimization menu entry can be used to customize behavior of the K4's analog-to-digital converters (ADCs). In general it should be left at the default setting of ON, which configures the ADCs for best response to very strong signals. The OFF setting will slightly improve preamp-off sensitivity."

All I know is that it works and it's amazing. As soon as I heard how well the K4 handled both the strong and weak stations, I knew that it was this feature that was making it's presence known.

The K4 includes the expected TX & RX 8 band EQ settings, a simple Macro language that you can use to assign to buttons or external software, and every "standard" feature that you would expect in a rig of this class. You can plug in a mouse and keyboard into any of the USB ports to use with the UX. The front USB port will power a wireless USB mouse / keyboard. I tested it with an Microsoft ergonomic mouse / keyboard and had no problem operating the rig as if I was running a PC. I will have more detail on mouse interaction in another post, but suffice it to say that the rig makes good use of the left and right buttons, as well as the wheel.

One function that I never got to work very well with my K3 was the CW decode. It worked sometimes, but I gave up on it after a while. With the K4, I just dialed up a station, set the RX filter to 400 (or less) Hz, turned on the text decode, and all of the sudden I was reading CW without any special adjustments. Couple that with a keyboard and even the most inept CW operators (like me) can have fun in this mode. And again, the RX in CW mode is just a joy.

Since I opted for the K4D, I also have the ability to run Diversity RX, meaning I can use two different RX antennas at the same time (one in each ear/speaker), helping me copy on the antenna that is receiving the best for a given circumstance. I've never had this capability before and having fun playing with it. For now, my RX antenna is a low 80m (roughly) loop feed with a DX Engineering DXE-BFS-1 into the MFJ-1026. This setup is neat because I can also adjust the gain of the RX loop. I originally set this up to help null neighboring interference and not as a true receive antenna, so I've ordered another active receive antenna (there are a bunch of antenna ports) to this will give me even more diversity RX options.

I have found a few quirks with the new radio. Some of these "quirks" can be attributed to my own learning curve and some are actual bugs. But reporting the issues discovered to Elecraft has resulted in superb response - in some cases the issue was already known with a fix being beta tested and in other cases I reported something new that was put into the next build. If you're considering purchasing one of these rigs (or have already done so), I highly recommend joining the Elecraft K4 list on groups.io where Elecraft principals hang out, along with much of the support staff. They also listen to feature suggestions, which is pretty cool.

There are new features coming in the next build that I can't wait to try out. I will be writing more about this rig, as well as posting youtube videos. In the mean time, if there is something you're curious about, ask away and I'll try to answer the best I can. I'm having a lot of fun with this new rig.

Elecraft K4D In the Shack

After a year wait, I received the Elecraft K4D and installed it in the shack. I have a lot of work to do to get everything configured, but I got the initial install done and made my first contact on 40 meters last night. Check it out:

A Pride DX300 is like a 44 year-old box of chocolates.

You never know what you're going to get.

First boo-boo on this job was mine. We install a circuit breaker on the rear panel to protect the small transformer. The Pride's 10-Amp fuse will keep it from burning down your house. But an overload on the small transformer that powers the grid-bias, filament and relays will cook it before that fuse can trip. This is bad juju, since nobody sells a direct replacement for it. Have to drill a 3/8-inch hole just above the fuse holder to mount it.

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Just one problem The twisted pair of black wires that got damaged here were glued to the inside of the rear panel. And in just the wrong spot. Shoulda looked first. I'll admit this is a first. Been servicing this model for 44 years or so. First time I've seen this. Only a nuisance, though. Got the wires spliced and on to the next problem.

It wasn't obvious at a glance, but somebody had installed the wrong tube socket. Seems to me in all these decades I have seen exactly one of these sockets actually go bad in this model. Somebody thought this one was, and replaced it.

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The one reason I question the guy's judgment is the socket he chose as a substitute. The socket at the bottom of the pic is the new one. Same as the factory socket. Has a metal ring all the way around it with a mounting ear on each of four corners. The socket in the foreground is wrong. Pins 2, 4, 6 and 8 are connected to the tube's cathode. The reason for using four pins in parallel is to reduce the inductance of the tube's circuit path to ground. I'll skip putting people to sleep with why that matters, but in this case it creates a problem. The tube never shuts off. It's always "keyed" no matter what the main relay is doing.

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The reason is this socket. The correct socket for the Pride has all the tube's pin lugs insulated, not connected to anything but the pin of the tube plugged into it. This socket is different. The four flat mounting eyes are connected directly to the four cathode pins, 2,4,6 and 8. Mind you that for an amplifier running at 150 or 420 MHz this is a clever way to shorten that path from the tube's cathode to ground.

But the Pride runs at 30 MHz and under. The tube's cathode is what we switch on and off, grounding it when the relay closes. Opening the circuit path from the tube's cathode to ground shuts it off.

But not with this socket. Just when you think you've seen everything. I was fortunate to have one socket of the correct type on hand, installed it and sent the customer home with a working amplifier. But we bought that socket in 2003 or so. Yep, that one just doesn't go bad very often.

Now I can't find anyone who will sell me more of them. EF Johnson type 124-0107-001. Unobtanium, so far.

So here is the clue I missed. Customer says it's stuck on High, won't go to Low side. The High/Low switch makes no difference. I just assumed they got it backwards. The more-common fault is a Pride stuck on Low side. High side is selected by shorting across a resistor in the tube's ground (cathode) circuit. When the connection to the High/Low switch goes bad, you get Low side all the time. A common fault, really. I just assumed he got it backwards.

But stuck on High side? Never saw that. Not until this specimen. Like The Who, I won't get fooled again. Not by this symptom. But the guy was right, it WAS stuck on high side. As a bonus, the tube was never really on standby. It was powered and pulling current the whole time the power was on and the fan running, whether you keyed it or not.

Just when you think you've seen everything.

73

Building a Homebrew Manual Tuner

I have finally began putting together my manual tuner. I rolled those two inductors about 3 years ago. I got busy, and sidetracked. Now, I've just mounted them on the board. I know, primitive, but what else do I do...
What I will likely need is some of you who've made your own to offer tips along the way.
Maybe this will keep me focused.
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Vertical fan dipole.

Needed a 220Mhz antenna. So I added it to my 2m/70cm fan dipole. Now it is a 144/220/440 vertical fan dipole. Working okay.
Yes, it isn't a 17' tall high gain vertical. It does get me into local repeaters and local rag chews. I also bought the tri-band Btech UV25×4 mobile to use as the base radio. It works okay, too.
I know. Not much of a review... oh, well. It works and that's what I wanted. One that works.

MFJ 849 SWR/Power Meter

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This meter has always intrigued me. It's costly - $230. And made by a company that sometimes has difficulties with Quality Control. Despite that, I bit the bullet and got one.

The good:

1. Large, 3.5" easy-to-read display.

2. SWR at-a-glance. No time spent adjusting the set point or interpreting a cross needle reading.

3. SWR accuracy appears splendid as readings vary only a few hundredths from those of my RigExpert analyzer. For example:
AA-35 MFJ849
28.300 1.06 1.04
28.400 1.02 1.02
28.500 1.07 1.05

4. Forward power accuracy appears pretty good too. I have no numbers to compare to as my analyzer doesn't measure power. Here are the power settings on the radio compared to the meter readings:
Radio MFJ 849
5 watts 4.86 watts
50 watts 48.76 watts
100 watts 99.92 watts

5. It also displays reflected power.

6. Once you unkey, the readings remain on the screen for a few seconds before reverting to 0.00.

The not-so-good:

1. The meter claims to be a peak reading meter but it clearly doesn't have peak hold. When transmitting on SSB, the numbers jump all over the place. And quickly. o_O Power readings are pretty useless really. Unless you're whistling. The SWR readings jump as well but don't vary by much and are useful. The best results, of course, are determined using a steady carrier like CW or AM.

2. Maximum of 200 watts.

Conclusion? I like it. A lot. (y)

I posted this thread in the Ham Equipment forum as the meter works on both HF (1.6 - 60 MHz) and V/UHF (125 - 525 MHz). But set to HF, it would be great for CB as well. (As long as you're under 200 watts.) :p

Homebrew 1/4 Wave 10 Meter Ground Plane

Easy Peasy. Works great!

Used this: https://m0ukd.com/calculators/quarter-wave-ground-plane-antenna-calculator/

Came up with 98.77" for the vertical. Had a Buddistick shockcord antenna I trimmed to 99 inches. Aluminum tubing or even a crappie pole and wire should work as well.

Attached it to a typical stud connector and mirror bracket atop a 4.5' light stand from Lowes. https://www.lowes.com/pd/CRAFTSMAN-72-04-in-to-72-04-in-Plastic-Work-Light-Stands/1000655903

Used 16 ga. wire for radial. Started with 110" and trimmed for lowest SWR at 28.400 MGZ (10 Meter Calling Channel). Wound up with a SWR of 1.02 using a tick over 100".

Trying to approximate an angle of 76.5 degrees, I attached it to the top notch on my electric fence post. (76.5 is the recommended angle for achieving an impedance of 50 ohms when using a single elevated radial. 45 degrees is recommended when two or more or used. https://www.qsl.net/kk4obi/Elevated Radials.html.)

10 meters is still pretty quiet but opens up occasionally during the day, especially in the afternoons here in north Texas. When it does, it is mostly DX and rarely stateside. :)

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