The Hardware Store 40m Magnetic Loop Antenna

A while back, I wrote up and submitted some info to QST antenna design competition on my 40m Magnetic Loop antenna. The contest is over so I am now publishing the write up on this site on the Projects page. The direct link to the file is here.

The write up details the design and construction of both the 40m Loop antenna and its High Voltage capacitor made from Copper tubing. Nearly the entire antenna can be made from parts gathered at your local building supply store. Hope some of you find this Useful!


Operating During Current Increased Solar Activity

I just wanted to document some observations I made during the current solar activity. Solar flux index was in the 120 range today with the sunspot number around 79. A CME slammed into the Earth’s atmosphere around 23:00 Zulu generated by an X class solar flare day before yesterday. The K index jumped to 8 indicated a major geomagnetic storm/blackout.

There was quite of bit of activity here. I made an SSB contact with a ZL station who was a strong 59 on 20m. Also made a strong 59 with an HI station. I heard ZS3D very clearly tonight on 40m but he did not copy my signal. 20m was open well after dark. So even with disturbance in the geomagnetic field, communications across several bands was open to DX.

Update 9/8/2017: 40m band was wiped out locally early this morning. No DX to Asia and few stations showing up on JT-65. Noise did not appear to be loud but very broadbanded and deep. Now at 16:45 Zulu the K index is at 8 indicating a severe storm. SFI is at 123 and the SSN is at 94. 80m and 40m is completely dead now. Some light traffic on 20m. 17m and above are dead now.

Here Comes the Sun…

After months of declining solar activity, our sun suddenly perked up. Today we had a solar flux index of 132 and a sunspot number of 122! These numbers are close to what we were seeing at the cycle maximum in 2014. Surprising activity and a X class solar flare and associated CME. 20m and 15m were noticeably stronger today on SSB. Made some good DX into the EU.

Ham Shack Changes – Part II

Configured a Pelican case to carry the FT-450D and an MFJ-4230MVP 12V power supply along with the microphone and assorted cables. The case has two “levels” so there was plenty of room. I plan to use the FT-450D portable with antennas that can be matched with the internal 3:1 tuner. So this is my FT-450D “go-kit”:


I have a QRP version of this with the FT-817ND in another case. There is also a smaller case now which holds the Netbook and cables needs to connect either rig for digital modes. I have one more smaller pelican case to configure for solar charged portable operation with the LiFePo batteries.

A Cool Idea for a 20m Hamstick

I found this configuration for a single 20m hamstick antenna which may be a winner for balcony operation at South Padre Island. The hamstick connects to a T connector. One end of the T connector goes to the feed line and the radio. The other end has a shorted 1/4 wave length (corrected for cable VF) of coax as a counterpoise. Here is the configuration (thanks to PD7MAA):

no ground antenna

This assumes the stub is RG-58 with a velocity factor of 0.66. Other coax types simply calulate based on the new velocity factor.

Antenna Experiments Continue

First up is a broadband EFHW using an auto-transformer wound on an FT240-43 Ferrite toroid. I used 18 gauge doorbell wire (had to remove the outer jacket of the wire pair first. The basic wiring looks like this (thanks to PA3HHO):


What is not shown here is a 150pF capacitor across points A & B. Here is the completed toroid:


Here I test the matching by connecting a 3.9KOhm resistor across point B & C along with the 150pF capacitor across A & B. Here is the SWR plot:


SWR is below 2:1 across nearly the entire band 80m to 12m 10m is 5:1 well within range of a tuner. I will mount this in a box with a UHF connector and two banana jacks, One for the antenna wire and the other as a ground connection. Once complete I’ll try first with 40m 1/2 wave wire. That should give me a good match on 40m, 20m, and 15m. The wire will be around 66 ft long.  I should be able to add 80m by adding a loading coil and an additional 2.5m piece of wire. Planning to un the first 10m of wire up the travel mast then bring the rest down as a sloper.

New Antenna Projects

I am going to build a matching transformer for a multiband EFHW antenna. The idea is to use a 1/2 wave wire and not have to use a tuner across several bands. More details to come. Also will build an inverted V for 20m to use as a reference antenna.

ICOM 7300 – First Impressions

I spent some time playing with the new IC-7300 transceiver this weekend on various modes. My first comment is that having used an IC-7100 for some time I was instantly familiar with about 90% of the IC-7300 controls. Most of the buttons are labeled the same and many of the setting menus are also the same. First thing I installed was a headset adapter so I can use the Koss SB-45 headset. I needed a plug adapter (which I luckily had on hand) to plug in my Vibroplex paddles. Rig control via Ham Radio Deluxe was fairly straightforward as the USB drivers are the same as the IC-7100.  I started operating on 20m during the North America QSO party on Saturday with the 1/4 wave verticals.

My first impressions are that the rig works well (and possibly better) than the IC-7100 on SSB. My signal reports were solid 59’s and occasionally 59+ all across the USA. Also made some DX with favorable reports.  Receive options make it easy to adjust RF gain controls and filters to help clean up the signals. I like the overload indicator which tells me to back off on the preamp or RF gain or both. The main learning curve for me thus far is in using the scope screen. Once you play with this awhile you get used to operating more visually. You can see whats going on across the whole band and find signals to tune into or find dead spots where the frequency is open. It is also easy to switch in the audio monitor to hear what you are transmitting.

Also tested digital modes JT-65, FT-8 and PSK31 after configuring the software for the rig. The audio scope helps look at the signal quality on digital modes. I did not find any notable differences in using the 7300 vs the 7100 on digital.

So overall I am impressed by the new rig especially on SSB Phone. I’ll likely expand on this review as I get some more time on the rig but I am happy with what I have seen thus far.

The IC-7100 is now setup as my base VHF/UHF rig and I hope to play with DSTAR on it for the first time sooner rather than later. I will continue to have it connected to my PC for rig control and can switch in HF when needed.

Ham Shack Changes – Part I

I made some changes to the Shack today. First up was removing the FT-450D and the FT-2900R and their associated cabling. The FT-450D will become a portable station along with an MFJ-4230MVp Power Supply in a pelican style case. The FT-2900R will eventually make its way into my Ford F-150 for 2m mobile operation. The IC-7100 is now working as my VHF/UHF rig. I have kept the rig control and HF connection intact so I can also use it on HF. I have now installed a new Icom IC-7300 for my HF base rig. Installation was stratight forward and operation is VERY similar to the IC-7100. The main new features are of course the spectrum scope and the filtering. I have Ham Radio Deluxe, N1MM+, JTDX and WSJT-X configured and working with the new rig.

Today is the North America QSO Party so there is an active band on 20m to play with the new rig. I’ll review later as I have more operating time built up on the rig. Here is the new “minimalist shack”…so far:


Addtional changes in the works are:

  1. Swap my ground braided strap connections with copper strap.
  2. Install S9 Antenna and radial plate
  3. Secure the FT-450D and FT-2900R in their new homes

WSPR Data collected from the 20m Hamstick Vertical Dipole

Here is 24 hours of WSPR data collected from the 20m Vertical Dipole:


There were 114 unique receive spots and 90 unique heard from spots with 1W transmit. This seems low compared to N5Cey’s 20m 1/4 wave vertical which typically receives 180 to 200 unique spots from his QTH near Los Fresnos.

I did some A vs. B tests on SSB yesterday switching between the 1/4 wave vertical and the vertical dipole. This time I used a remote receiver using I connected to a station in the San Fransisco area and monitored my voice transmissions. In this case the vertical dipole came in about 1 S units stronger. I then switched to a station in New Jersey and the opposite was true!

I am going to do some additional testing on various 20m vertical configurations using WSPR over the next couple of days.