Tag Archives: QRP

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.

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:


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.



Transmit Power Using JT-65

I came a cross a very helpful web page in determining the amount of power needed for JT-65. It is called dbCalc and allows you to enter your transmit power and signal report and then calculates what your report would have been with other transmit power levels. I tried this out today on 40m JT-65, lowered my power in half and still made several DX contacts to Japan and Argentina.  You can easily measure how your signal is doing at a given power by sending a CQ and then checking the Pskreporter reports. Feed these into dbCalc and you can optimize your power settings for given band conditions. I suspect that in most cases operators are using a lot more power than necessary to make JT-65 contacts which makes it harder for weaker signals to get through.

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.

Getting ARES Ready…Hurricane Season Approaches

Hurricane season officially begins on June 1st. Our local club is gearing up some activities to support ARES operations in the event of a storm. We will be setting up a 2m digital simplex net on Thursdays at 7pm local time on 146.580 simplex using MT63 2000. Net control will be Cliff, N5CEY.

I will be net control for an HF voice and HF digital net on Saturday afternoons. Times and digital modes are yet to be determined. NVIS operations on HF will be desirable for these nets. I suspect that my current antenna (the DXtreme 53′ end fed) works fairly well as NVIS as it is up horizontal no more than 20 feet up. This net will give me a chance to test the 40m magnetic loop as NVIS. I am also thinking of modifying the homebrew buddipole to work NVIS as well. There is a PDF file that shows a simple way to modify a Buddipole to work NVIS portable. Yet another option is to build an easily deployable NVIS antenna for 40m and 80m per these instructions (thanks DX Engineering).

I am looking into a few choices for HF digital modes. MT63 1000, PSK31, Olivia and NBEMS. I am thinking of eventually asking net participants to limit power to 20W max to simulate off grid operations.

Last but not least, getting more local hams to test their HF rigs on Winlink using WINMOR. I cranked up the IC-7100 this afternoon and easily sent some emails on 40m to a node in Houston on 20W. Here is a good tutorial on setting this up.

Citizen Science with Amateur Radio

Space weather quarterly has  great article on how ham radio operators are contributing to the study of space weather using data collected from WSPR beacons as well as the reverse beacon network.

The article can be read here:

Space weather quarterly

Back on the Air!

Over a month has gone by since my last contact on HF. I have been out of town on business travel followed by a week of vacation in Arizona and New Mexico. Missed Field Day…but had a lot of fun seeing the Grand Canyon! Tonight, I warmed up the Icom 7100 and made some Canada Day SSB contacts and ran a bit of JT65 and JT9 on 20m and 40m. Feels good to be making some log entries again! The Fourth of July is coming up fast and I will be trying some QRP contacts from South Padre using the magnetic loop antenna. Hopefully, I will be working on some of my projects next week. I have the parts to build out my solar generator box and am ready finish my 40m NVIS loop. Propagation is looking grim these days and I am starting to think of ways to up my game on 80m, 40m and 20m.

Solar Powered Portable Field Day Station

I presented a seminar today at our local Ham Club entitled “A Solar Powered Portable Station for Field Day”. Here is a copy of the presentation and an associated spreadsheet for making power budget calculations.

Solar Powered Portable Field Day Station

Power Usage Calcs for Battery

The presentation went quite well and we are getting more local ham’s attending the C.H.A.R.R.O. club seminars. Next month no seminar as it will coincide with 2016 Field Day.

WSPR tests My Magnetic Loop Antenna

We had a discussion at our club meeting this morning that got me thinking about how to do some antenna testing using WSPR. Turns out I had the cables needed to control my FT-817ND and run WSPR with my mag loop antenna. I have been underwhelmed by the loops performance on 40m and the design spreadsheet indicates that my efficiency is quite low on that band. This is why I am working on building a larger 40m loop.

I setup the magloop this afternoon and ran WSPR on 40m with 5W out. The only station that could hear me was N5CEY, Cliff just up the road from me in the Los Fresnos area. He could not hear me on the lower power levels. This pretty much confirms that the loop doesn’t do well on 40m.

When I switched to 20m I was being heard all the way up into Canada on 1/2 Watt. This was also pretty consistent. I will try this again tonight and see if the band conditions after dark help this out. Meanwhile I am collecting some interesting data that I can use to compare against the new 40m loop when I have it finished.

This was also the first time I ran digital modes on the FT-817ND and this went pretty smoothly. The rigs programming cable also works for CAT rig control and I was using the original USB sound interface I bought to go along with the FT-450D. No issues except that the receive audio looks to be on the high side.

Update 5/22/2016: I ran the FT-817ND on 5W 40m WSPR from about 5pm through 7am. The results were quite different from what I noticed initially. I had considerably more spots during the night including one from Spain. The receive portion seems to work much better as well as I had numerous spots in Europe:

wspr map

This is consistent with what I would expect from decent band opening on 40m during nighttime hours. This leads me to think that the loop as is would work considerably better than I thought during nighttime conditions.

BTW, did I mention the loop was operating indoors?