Tag Archives: solar power

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.


Post Field Day Report

I got a late start to field day this year due to a late breaking family commitment. Our club tried to setup at the local weather station but cancelled operations due to a large noise source crashing the bands at that location.

I started operating about 19:30 UTC. I started at 5W on SSB but over the first hour only made one contact. The band conditions were not good on 20m with lots of QRM and QSB. I added the amplifier and started to work on 45W. My power draw was significantly higher but my Q rate increased. The solar panel kept up with the power consumption even though there was quite a bit of cloudiness. I continued to operate on 20m until dusk when I switched to 40m. Overall I made 60 Phone contacts over the course of about 8 hours. My score this year will be lower even with more Q’s due to the higher power I ran. I did not get a chance to run digital.

What worked:

  1. Digital logging – netbook needed one charge cycle during this period. The 12V to 18V DC-DC converter was running at abou 2.2A during the charging cycle. I used a 7Ahr for this through a spare Solar Charge controller. I am going to look at a tablet for next year.
  2. The EFHW antenna worked great on 20m.
  3. SOTAbeams travel mast + TV tripod worked great to support antenna with no guy lines.
  4. Solar generator box had enough juice to supply the day’s activity even at the higher power consumption and had some power to spare.
  5. Tube Tarp came in real handy as shade. Luckily no rain on Saturday. I’ll do better with the depolyment next time as I figured out how to guy it better.

What did not work so good:

  1. Can’t run digital mode while using an amp. The amp uses the ACC port on the radio but provides no pass through. I am looking at how I can accomplish this for next time.
  2. I don’t have the battery budget to run 45W phone for 24 hours. I figure I would have run out of power after about 12 hours. Partly cloudy day didn’t help.
  3. Didn’t take advantage of more 6 stations to raise Q count.
  4. Calling CQ consumes a lot of power. Need to refactor the power budget.

So I figure my score this year for 60 SSB QSO’s + bonus points for emergency power will work out to 310 for my 1B station. I am convinced now that I have to finish learning CW so that next year I can run 5W on CW and up my point count. A more directional antenna would be nice but a portable beam antenna remains elusive. For some reason I seemed to be doing better with stations in California than on the more densely populated east coast.

In summary, A great afternoon of outdoor radio fun and already looking forward to next year.

Field Day Preps Complete!

My Field Day preps are done. Tested the EFHW and its ready to roll on 20m and 15m. There is 12Ahr of solar charged battery ready as well. I won’t be able to join the club at the NWS office as I have a commitment in the morning I have to deal with. I may start late but I am ready for operations in the backyard. Will get some water bottles and snacks for daytime ops. There is a 30% of rain tomorrow afternoon so I’ll keep an eye on that as well to see if I need to deploy the tarp tent. Rain means clouds so that may help moderate the heat. Today the NWS is advising people to stay indoors between 1pm and 5pm!

Tested the EFHW a bit and am finding Common Mode Current issues if I run higher than 90W. The SWR increases with power and foldback starts kicking in if I try and run at 100W. This should not be a problem on FD as I’ll be running at 5W where everything behaves itself. I’ll be trying computer logging this year as well. If things get real tough on Phone I plan to try PSK31 and have setup some DM78- macros for that.

Looking forward to a great Field Day in the outdoors!

Linked EFHW Coming Together

I purchased the following for $1 at Home Depot yesterday to form links for the EFHW I plan to use for Field Day:

Photo Jun 21, 10 47 20 AM

These are buckles to make paracord bracelets. Here is how the resulting link looks like using these, a couple of cable ties and a pair of Anderson Power Poles:

Photo Jun 21, 11 01 22 AMPhoto Jun 21, 11 01 32 AM

I have made initial wire cuts for 15m, 17m, 20m and 40m. I also cut 1/10 wavelength counterpoise wires for each band. I have also prepped the Travel Mast and the TV Tripod so I will hopefully setup later this afternoon (when it cools off a bit) and tune the wires. I’ll run 15m-20m as a vertical and 40m as an inverted V.

The only other prep I am working on today is I’ve taken the solar generator box I built last year and set it up outside with the two 15W panels to charge them up.

Update: Just did the calculations on the 40m inverted V and found that I probably don’t have enough space to lay that out in the backyard due to obstacles. Will configure the first half as a vertical and then the remaining half as a sloper which I’ll aim towards the north and terminate 4 feet off the ground. Only need a radius of about 16ft. A quick run on EZNEC show the following pattern:


Plan B for Field Day Antennas

I was pondering what I would do for a Field Day antenna after yesterday’s debacle with the Homebrew Buddipole and military mast. It just hit me a few minutes ago. I’ll run the EFHW antenna as a vertical on 20m and 15m. It is a proven performer and it is resonant thus no tuner needed. I’ll use the TV Mast tripod Cliff gave me to support it during the contest on the SOTABeams Travel mast.¬† What I will do this week is set that up and cut some links for 15m, 20m and possibly even 40m. Will be much more manageable as a vertical. I have 5 days to work out the details. Tomorrow morning I’ll put put the battery packs and solar panels to top off the charge. This should work!

Field Day Antenna Selection

Working on Field Day antenna selection this week. I am down to using the Homebrew Buddipole, Buddistick or end fed vertical antenna this year. I plan to operate as 1B battery operation so I am limited to 5W on SSB. This will be my main challenge  this year given the worsening band conditions as the solar cycle continues the drop.

A previous post showed some data on the homebrew Buddipole mounted at 16 ft with a painters pole. I am working on a few tweaks now that will bring resonance into the band and simplify the azimuth adjustments.

The Homebrew Buddistick served me well in 2015 but band conditions are shifting. Here is some modeling data comparing the Buddipole at various heights vs the Buddistick on 20m:


The Buddipole at 16ft and 20 ft outperforms the Buddistick down to about 25 to 20 degrees. The Buddistick has more gain below these take off angles. At 30 ft the Buddipole is better or equal to the Buddistick from 60 degrees all the way way down to zero.

One thing I could do is use both antennas and switch back and forth as needed. This would not be overly complex to do. My challenge is getting the Buddipole up above 16 ft. If I can get setup using the military poles I can get the Buddipole up to 30 ft and only use the one antenna.



Field Day Preps Continue

I have two more weekends to prep for 2017 ARRL Field Day. Next weekend I plan to test the Homebrew buddistick on 20m WSPR and compare to the 20m Buddipole I tested last week. I need to complete a 1:1 current balun for both of these antennas. I am also reconfiguring my go-kits. I have a case for solar power generation, another to carry gear for digital ops, and yet another for the FT-817ND and other equipment. I have also sourced a “tarp tent” which I hope to test next weekend as well. Just missing a field portable chair and table at this point. Need the shade and will need plenty of water as well.

My plan now is to run solar powered battery operation from start of the event on Saturday, run 20m & 15m through the day then switch to 40m once the sunsets and operate till the late evening. I will not likely operate on Sunday at all. I plan to start with SSB and switch to digital PSK31 if band conditions limit QRP SSB operation.

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!


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.


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).