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Kenwood Announced new TH-D75A

Today at Hamvention 2023, Kenwood announced and is showing the new TH-D75A 2m/220/440 handheld radio.


Features are largely the same as the TH-D74, but the new radio adds built-in Digipeater capability for APRS, as well as a USB-C for data transfer and charging. Details are just emerging; price and release date are unknown at this point.

Ultra Portable operating in the Sierra Nevada Mountains

This past weekend my wife I and met our daughter and fiancée at a remote cabin campground up in the Sierra Nevada mountains in California near the town of North Fork and Bass Lake. The location is quite remote. I needed to pack light as I had to go from there to another city on a business trip, so I packed up the Elecraft KX2 with a couple of batteries and the Elecraft AX1 antenna, the AX2 antenna, and a couple of ground radials cut for 40, 20, and 10 meters. Here's a few pics:


Starting on 17m (the AX1 antenna has a switch for 20m and 17m), I found the propagation round table active and checked into the station running it out of Arkansas. We had no problem having a good QSO. The path was good between Arkansas and California but not between any of the other stations.

The location of this camp site is where the devastating Creek Fire of 2020 ravaged. The desolation is breath taking, but the new forest growth and snow on the peaks is beautiful at the same time. I checked 20 meters, but it wasn't happening so after a while I added the AX2 40 meter coil, changed the ground radial and had fun there:


7.178 is home to the 24x7 Filipino net on the U.S. West Coast and I check in there often because there are always lots of stations from all over the pacific and they are super friendly. Sure enough, with only a few watts, I was talking to stations all over central California in no time. I also dialed around and listened in for a while and even made a contact with one of my locals back home in SoCal.

This little ultra portable setup is really fun. When propagation cooperates, it's amazing what you can do with 10 watts or less and an extreme compromise antenna. The rig weighs nothing and the little 4 cell battery pack that fits inside or can also plugs into the external port lasts for hours. The little boom mic in the pic is from ebay. Now I'm off to the outskirts of Albuquerque with the same setup to see what I can do when I have some down time from work!

A 160 Meter Vertical Buddipole Antenna Experiment part 2

In Part 1 of this topic, I showed how I accomplished creating a 160 meter vertical using mostly Buddipole parts, although I ended up using a Chameleon shock cord extension and whip which I already had for the length above the load coils. For this segment, I acquired a cap hat from a local ham that has 3/8-24 threads for use in mobile or portable antennas. I believe the cap hat originated from Chameleon, but I'm not 100% sure.

I put the cap hat between the shock cord extension and the whip:

The immediate, expected effect was that the low SWR point moved down lower in the band than desired. So now I needed to re-tap the coils. The capacity hat made the tuning process easier as adjusting either coil became more forgiving than without the cap hat. Before, the process was super finicky trying to figure out which coil to adjust to achieve the lowest SWR, but with the cap hat I could adjust either to move the low SWR up and down the band. In the end, I found that the best combination was to leave the top coil tap in the original position and then adjust the lower coil tap for the desired frequency. I ended up taking coinly a couple of turns out of the lower coil, but the process was much easier and more forgiving to adjustments with the cap hat installed.


Here's the new SWR plot; 1.74:1 at 1.903 Mhz, which is just slightly better than before. It has just a hair wider bandwidth, about 10khz more under 3:1.


I also tried this antenna with only 1 load coil and the cap hat, but there just wasn't enough length in the antenna to get it resonant in the 160 meter band - it was closest around 2.2 Mhz. So, I had to go back to my original idea and use two of the low band coils. Now its' time to make some more contacts!

A 160 Meter Vertical Buddipole Antenna Experiment

I live in the Los Angeles metro area on a small lot but have wanted to try out 160 meters for years. I have considered building or constructing various types of antennas that will fit on the property and even purchased a coil loaded sloper that I was going to suspend from a palm tree in my back yard. The palm tree was taken out because it became a hazard to the power lines that run along the property border in the back yard, so that plan was gone with it.

I've had a deluxe Buddipole kit for years, which I use mainly while RV'ing in places that won't let you put up wires. Last year I was looking for my Buddipole low band coil for 80 and 40 meters and when I couldn't find it, I assumed that I loaned it to someone and never got it back. I ordered another and of course, promptly found the one I already had. This led me down a path trying to figure out what to do with two 80 meter Buddipole load coils...and the 160 meter Buddipole vertical experiment was born.

My idea was to stack the two coils to create a pseudo 160m coil. I stacked two arms on the versa-tee and then the two coils. Then I used a 12' MFJ telescoping whip on top of the coils. I ran a single 160m 1/4 wave (roughly) ground wire out around the property for counterpoise and hooked up the Buddipole Triple Ratio Switch Balun at the feedpoint using the 1:1 setting. Using a Rigexpert AA-600 was absolutely critical for helping me understand the tuning of this arrangement. I figure that stacking the two inductors might cause them to interact in unexpected ways, but was hoping that the proximity of the two would make them act more like one big coil. I was wrong about the latter.


Ultimately what I found is that I could adjust the lower coil tap to find the best SWR on the frequency I wanted, and then adjust the top coil to affect the SWR curve and bandwidth while making the SWR dip even more. I expected that the bandwidth for a low SWR on this band would be very narrow. Making small adjustments and then sweeping with the analyzer helped me quickly understand how to adjust and it wasn't long before I had something reasonable. Next I decided to replace the telescoping whip to get more metal in the air, so I took it off and put a Chameleon shock cord whip and extended base on top of the load coils to make the whip a total of 17' above the coil. I extended the Buddipole tripod up just a little bit to get the coils about roof eave height, but not so high that it would tip over. The antenna is sitting right outside my shack so the coax run is less than 20 feet.


A quick retune of the coils, a bit of shortening on the ground radial, and I got an SWR of 1.8:1 at 1.915 Mhz. The antenna is under 3:1 SWR between 1.860-1.945 Mhz.


The 160 meter band isn't that wide, so the tuner in the Elecraft K4D easily tunes up the antenna at any frequency I've attempted. With such a short coax run, the coax loss using the tuner in this manner is small. So the real question: Does it work? Yes! Obviously this not a very efficient antenna. The noise floor in the big city is HUGE. In the short time I've played with it at night, I haven't come across many strong SSB stations, but I've heard a few weak ones...I will continue to listen when I have time on the weekends to see if I can make some phone contacts. I decided to try some FT8 - there is quite a bit of activity there. Currently my 100 watt station is heard better by others than I can hear - likely due to the high noise and local interference. But I have made more contacts than I expected in North America.

Here's a screen shot of my transmit activity last night and the stations that heard me over the course of a couple of hours:


I'm not done experimenting with this antenna - a local ham is gifting me a Chameleon cap hat that I am going to integrate to see if I can eliminate the top coil. I will also experiment with different RX antennas while using the Buddipole as the TX antenna. When I started this journey, I googled around to see if anyone had come up with a way to use the Buddipole system on 160 meters and came up empty. I'm pretty happy that I was able to accomplish even this much, so stay tuned while I see what else I can do with this setup on 160 meters on a postage-stamp sized lot in the L.A. metro area!

Edit: See Part 2 where I add a capacity hat.

Ham Shack Rebuild

After almost 20 years, it was time to do some remodeling in the house, and I decided to include the Ham Shack / Office in the process. It took me forever to find a desk that is large enough to double as a home office and ham shack, but I finally found one and completely redid the ham/cb station. Here's a few pics!





Tower build out

After almost a year I'm finally motivated to move forward with my tower install. Below is a photo montage of the steps in the process.

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Prepped and painted the tower

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Time for the hole digging.

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Had the concrete delivered and placed right next to the hole.

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Tower has been planted thanks to the help of a few friends! The plan is to use a 4 element beam with a GP on top. I'll post updates as time goes on.

New truck new install

The boy wanted his truck back so had to uninstall the radio and antenna and install in the f150. What a pain!
Didn't have the correct mount for the sirio so had to do a temp antenna till the new mount arrives later this week.

Tidradio bluetooth radio programmer

Tidradio contacted me and asked if I would like to take a look at a new product: their bluetooth radio programmer and software for the various Chinese radios such as Baofeng. Of course, I couldn't turn down the opportunity. I also picked up a new Baofeng UV-5RA , the high power model, to try out, as well. Here's a video I made, reviewing the product:

It's about $25 on Amazon:

Elecraft K4D First Impressions

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


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:

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: