Monthly Archives: April 2017

Not Even in May Yet and Already Near 100° F…

…and did I mention the winds? Been hard to play with the vertical antennas these last few days. It is very hot outside and the wind is blowing up to around 30 MPH. The tests I was doing with the end fed in vertical configuration had to be halted yesterday as the mast collapsed again. I have a major construction project about to begin next week in the backyard so this is not the right time to deploy the radial field.

After giving it some thought I sent up the 40m 1/4 wave vertical as before. This time I am using duct tape on the travel mast and it seems to be holding together better. The other big change is that I am using only four ground radials each 27 feet long. This will make it easier to pick up if the construction requires me to move. How does it work with only four radials? Surprisingly good! Made several contacts during the Florida QSO party on 40m SSB without issue. Used the tuner to match on 20m and 17m and made several solid contacts on those bands as well including an SSB contact to Spain on 20m. Will be running WSPR tests on various bands over the next few days as NO5V/6. Hope the duct tape holds!

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KB5TMC—Get Well Soon Jerry!

Jerry is one of our club members, coordinates local license testing and a good friend. He has had some medical issues these past few days but appears to be on the road to recovery. Get Well soon Jerry!

Planning an upgrade to the Mini60 Antenna Analyzer

My posts on the Mini60 antenna analyzer remain the most popular views on this blog. I have not been using it much since I acquired a RigExpert AA-230 zoom. The RigExpert is so easy to use and provides a wealth of information when tuning antennas. That being said, I have not given up on the Mini60 as I intend to use it on Field Day.

I am going to be retro-fitting a bluetooth module to the Mini60 over the next few days. I need a USB to TTL adapter to program the bluetooth before installation and then wire it into the PCB. Worst case I end up trashing the mini60…best case I’ll have a wireless Android interface for this over bluetooth. Stay tuned as I’ll post some detail on how this proceeds.

20m EFHW is Back On The Air!

Lawn maintenance time again and I still haven’t permanently deployed my radials. Took the 40m 1/4 wave down today and picked up the radials.This is a tedious process but not too time consuming. I had the most difficulty in getting the travel mast to retract as it sticks sometimes. Went ahead and setup  and re-tuned the EFHW for 20m as it doesn’t need radials to get hung up in the lawn mower. I am running WSPR as NO5V/1 now to compare against earlier data. I made several USB contacts this afternoon with it. Band conditions were terrible as geomagnetic storms are still raging. The QSB was awful but I did manage to secure a solid 59 into Vancouver.

Fixes to the EFHW Matchbox

I have decided to use the EFHW antenna as my primary portable antenna. My previous reports on this antenna have centered around testing on 20m which performed quite well. I want to set this up now for multi-band operation using connection links to add or remove wire as needed to tune it on a specific band. The capacitor I used tested between 9.5pF and 310pF which would let me operate between 40m and 10m. I was disappointed to find the matchbox would barely tune up 10m and would not come even close to 40m. I originally suspected stray capacitance and yes some did exist but what I found today solved the mystery. Turns out that I had connected to the wrong lug of the capacitor which limited the upper capacitance to around 100pF. I changed the connection point and am now able to tune down to 40m but have lost 12m and 10m as there is added capacitance on the low end as well. So my plan now is to run this match box on 40m, 20m, 17m and 15m which should be a pretty good range for this point in the solar cycle. The 40m half wave will be ~ 66 feet long so I’ll likely figure a way to configure that as either an inverted L or as an inverted V.  All other configurations will be as verticals. Next step is to cut a wire length for 15m then add wire to get to each of the successive bands. Band changes will require taking it up and down but it will be resonant. The backup antenna will be the end fed 9:1 matchbox and a tuner. Both will fit nicely into the soon to be reconfigured go-box.

Saturday’s Radio-activity

Had a good club meeting this morning and chatted on quite a few and varied radio topics. Will be starting the HF voice and Digital Nets next week on 40m at 1pm local time. Voice will be on 7.250 Mhz and MT63 1000L digital following shortly thereafter on 7.060 Mhz. There is a major geomagnetic storm going on now that has impacted the HF bands. Not much in the way of QSO’s going on right now except for JT-65. Good time to play with some other projects.

Tested the new 10Ahr LiFePo4 battery this afternoon with the solar charge controller and a non-radio load (5V USB charger on 12V lighter plug). Pleased to report this battery worked like a champ and is a drop in replacement for the lead Acid SLA batteries. It is half the weight of the 7Ahr SLA battery and can provide at least 80% of its capacity without shortening the life of the battery. So I am replacing two 7Ahr batteries that provided 7Ahr of capacity at about 10 pounds with a single 10Ahr LiFePo4 that can provide 8Ahrs and weights only 2 lbs! Nice!

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I ordered a USB OTG cable from Ebay. This cable allows me to hook up and SDR dongle to an amazon fire with the SDRTouch Android app. The only downside is that you need an external power source to get enough power to the SDR dongle. I hooked it up to the USB charger I was testing with the new battery and it ran fine.

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Next Iteration of the Vertical Antenna – End Fed with Radial Field

I reconfigured the 40m 1/4 wave vertical as and end fed vertical by removing the 1:1 choke balun and installing the 9:1 matchbox as before. One big difference was that I connected the radial field to the ground lug of the matchbox. I have run 24 hours WSPR on 20m with the following results:

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Not bad at all with 132 unique spots thus far (on a fairly bad day of propagation indices). Will try this on other bands soon.

Checking Solar Panels for Portable Use

Decided to check the batteries and solar panels for portable use. Good thing I did as there is a fault of some kind on the 60W folding panel I bought off of Ebay. It started reading ~15V in bright sun but when I folded it up and then later took it out again is showing no voltage. I am going to have to open it up and debug the issue. Meanwhile I have two 4S, 10Ahr LiFePo batteries on the way. I plan to replace the Lead Acid SLA batteries in my go-boxes with these.

Update 4/20/17: The panel is hosed. I am going to try and salvage some of the cells and try to eventually rebuild it. This was a great idea but a poorly executed panel. I’ll likely buy a 50W foldup panel soon as a replacement although the other panels I have will work fine. The LiFePo batteries arrive today so I will be reconfiguring my go kits this weekend (hopefully).

Running 40m 1/4 Wave vertical on 20m

Overall I am very impressed with the 40m performance of the 1/4 wave vertical. For grins I am running 20m WSPR by running through the antenna tuner. The tuner found a match and after only 8 hours had enough unique receives to make the WSPR challenge yesterday. The count is now up to 123 and I expect to be on the board again with a very decent showing. I will continue testing on 17m then over to 80m and 160m. Not expecting much on the low bands but am interested in the results. I am not going to run on 15m because it is resonant on that band as a third harmonic to the 40m primary.  I’ll leave 12m and 10m on the DXxtreme as that antenna has proven itself well on those bands (when they are open).

Update on the 40m 1/4 Wave Vertical

Ran WSPR last night on 40m with the 1/4 wave antenna. Here is the Map as of this morning:

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Started running some JT-65 this morning and while difficult to run pile ups, I am getting QSO’s with JA by calling CQ. On my third one since starting this morning:

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Overall I am very pleased with the performance of this antenna. I’ll be doing some tests on 15m as well although the band has been quiet.