I was working slowly on how to add a 10m element to the 15m Moxon in preparation for the CQ WW DX Contest this past weekend. I ran into some mechanical problems and work got even slower. After thinking over it, I decided to try and finish the 20-15-10m fan dipole I had started some time back. I had already printed the dipole center and spreaders so I though why not? Gain at 33ft would be a respectable 6dBi and should give me some help running QRP during the contest.
The antenna went up on Friday morning. Tuning was way off when I started which I tracked down to some feedline issues. After replacing the feedline, I started seeing the appropriate SWR dips but they were not centered on the bands. I decided to try it anyway with the antenna tuner and made some test contacts at 5W.
I was unable to work the start of the contest on Friday night but thought I’d start in the morning when the 15m band opens up to the EU. I look out the window and… spaghetti on the ground. I raise the antenna and sort out the wires. The antenna hears beautifully with many, many signals. Unfortunately, no one can hear me. I bring the whole thing down again and now here it sits on the shack floor:
In retrospect, the spreaders should have been longer and tuning this antenna turns out to be a fairly painful process. I would have been better off with the 44ft doublet…
Field Day 2022 is now in the can and here are some experiences and lessons learned.
I setup outside under a patio umbrella and operated phone and FT-8 on 5W. Contacts were better than the last time at the park but conditions overall were not great. Weather was sunny, with peak temperature at 93° F with 53% humidity. Fortunately we had a nice southeasterly breeze to help keep things reasonably comfortable as long as I stayed in the shade..
I operated from 1800 UTC to 2330 UTC. The station was operational for a total of 7-1/2 hours at 5W and made 17 SSB and 22 FT-8 contacts. I made two FT-8 and one phone contact on 40m with the rest on 20m. 15m was very disappointing this year. I heard only very faint phone signals and while there were a few FT-8 signals I could not close any QSO’s. 10m was largely dead from my perspective. I am estimating my final score will work out to 455 this year and overall an improvement on the 19 QSO’s last year on 20W.
What worked:
Power – No issues with the solar generator box and the 100W panel. I logged 11.9 Ahr coming in from the solar panels and 12 Ahr consumed by the equipment. This works out to a 0.1 Ahr deficit from when I started operations indicating my battery is still fully charged. The last couple of hours saw a reduction in solar panel power in due to the lowered sun angles. Most of the session was under full sunshine. The laptop/FT-817ND combination consumed about 1.2A of current while idling.
Notebook great. FT-8 time synchronization was made with GPS dongle. The faster laptop decoded FT-8 and FT-4 signals without problems.
Digital contacts worked without incident this year as did logging.
This year I used the homebrew 44 ft doublet antenna. I had tested this antenna all week and found it to be a capable antenna. I took it down for some adjustments before FD started. I drove the mounting stake further into my somewhat soft ground then remounted the Spiderpole. Next I used a cable tie to attached the feedpoint to the pole at the top to keep it from swinging out so much. Lastly, I relocated the fence posts to dress the feed line towards my operating position.
Band conditions were as expected. VOACAP coverage analysis suggested it would be a slow start with 20m picking up after 3 pm local time. That seemed to play out as expected. 15m was for all practical purposes dead throughout the period. 40m contacts were of the NVIS variety. 20m started off slow on phone but picked up after a couple of hours. This seems to be a trend based on last year as well.
The FT-817ND worked like a champ and provided a compact form factor for portable use.
My only issue this year was that something in the antenna performance shifted once I re deployed the antenna. The Z-817 tuner could no longer find a match for 15m and 10m. I found nothing obvious to suggest why. The only suspicion I have is the cable tie up near the feed point. I will need to investigate this a bit. I switched to the LDG Z-11 ProII tuner and ran ops with that.
Overall a good portable session for field day. The equipment worked well and performance was really only limited by band conditions.
It is 1730 UTC and the station is setup for Field Day. As always some weirdness vs what I had tested earlier in the week.
Shade is provided by patio umbrella. Using my patio table folding table and a patio chair. 100W solar panel working well and providing slightly more than I am consuming so expect battery to stay topped off. Laptop running ok. FT-817nd running fine as well.
I have made some FT-8 contacts on 20m and one SSB contact to Alabama so it’s working. The bands are surprisingly quiet right now. 15m and 10m are dead quiet. Ready to start FD in less than 1/2 hour.
I did adjust the doublet antenna a bit and the Z-817 started having trouble tuning it on 15m and 10m. I switched to the z-11 pro II and it is tuning now. Not sure what the issue is other than perhaps I am loading the feed line?
Operating decisions have been made for tomorrows Field Day 2022. I have been having some mobility issues so rather than operate at a park I will be operating in my backyard. I have decided to use the 44 doublet antenna oriented broadside North with feed point at 10m. There is 50 ft of 450 Ohm Window line going to an 4:1 balun and then about 10 ft of RG-58 to the rig. This will feed the Yaesu FT817ND so I’ll be limited to 5W for better or worse. Power will be provided by my homebrew solar generator with it’s 20Ahr LiFePO4 battery and 100W solar panel. I will use the Dell laptop for logging and FT-8 and run it on 12V power as well. I have built a simple screen shield to help with visibility in bright sun. Timing will be provided by a GPS dongle. Any internet connection will be via my cell phone hotspot to simulate field use. My last prep today was getting the logging software and WSJT-X talking to each other.
So tomorrow I will redeploy the antenna, setup under a patio umbrella on a folding table & chair and setup the solar panel. See you on the air from STX in 24 hours!
I have been collecting WSPR unique spot data for the past several days using the 44 ft doublet antenna. Here are the results for the past 24 hours:
Overall, very good spot performance on WSPR particularly on 20m. 15m is solid during the day to points north of the QTH. 40m is very active after dark. 10m is spotty. I am using WSPR Rocks! website now for mapping. charting and spot analysis. The WSPR Challenge website has been down for about a month now but I have found that WSPR Rocks has similar data. Even with a 20m spot count of 258 it is still just under the top 100 spots.
Given the WSPR data showing good coverage to the north of my QTH and with the successful QRP tests on both SSB and FT-8 I think this antenna will work quite well on Field Day this Saturday.
I am continuing my 2022 Field Day Preps by setting up and testing the system. I am starting with my tried and true Yaesu FT-817ND. My plan this year is to use the new 44 ft doublet antenna in an inverted-V with feed point at 33ft. This will require a tuner. I am testing my configuration with the LDG Z817 autotuner. I did replace the batteries as they were the ones I first installed in this unit back in 2015 or so. The tuner works fine on all bands but 40m. It looks like it is just short of the range of tuning this band. There are a few things to consider on 40m:
Try and get a match by changing the window line length. This would be somewhat cut and try and may mess up the other bands.
Use the LDG Z-11 ProII which has some additional range. This would require external 12V DC supply connection as it is not battery powered. It is also physically larger. No interface connections are required.
Live without 40m on FD
I may opt for option 3 with the caveat that I can still operate on 40m but at rolled back power of 1W. I did manage to exchange email via Winlink (more on that later) on 40m with little difficulty even with the lower power.
I am using the new Digirig interface with the FT-817ND and I just say I really like it! One connection to the PC via USB port provides for PTT, CAT control and a sound card interface. The Digirig uses one cable to the ACC port and the other to the DATA port of the rig. In the case of the Z817 tuner I connect ACC to the passthru port. On WSJT-X I use the following configuration:
With this setup I can work FT-8 without issues. 5W seems to work well and I have worked some DX with this configuration.
This is all now working with the Dell laptop I have repurposed for quicker decodes. I received the 12V to USB-C power converter and have been using this to power the PC. For desktop tests I am using a 12V 7.5A power brick. This is connected to the laptop supply via a cigarette lighter connection. I am using power pole connectors to provide power to the rig. A GPS dongle is providing time synchronization in case no internet is available in the field.
This setup idles at about 1.15A which is just about where I was last year with the G90 and Netbook. Power consumption when transmitting FT-8 is about 2.35A. This year I will likely use either a 60W or 100W solar panel for the day. I used two 15W panels last year and while I did still have power at the end of the day I did consume more than I generated. This year I will also use only a single 20Ahr LiFePo4 battery instead of two 10Ahr batteries in parallel. When I check on the battery state after Field Day last year I noticed one battery was nearly discharged while the other was nearly full. That was a nasty charge imbalance.
I also setup Winlink with VaraHF on this rig and had good success exchanging email tests. These were done on 40m with low power to a local gateway. I was very pleased at how well that worked. I have also setup JS8Call and Fldigi but have not messed with them yet. I have also installed the N3FJP Field Day Logger and interfaced with the rig. I need to play with getting WSJT-X and the logger to talk with each other.
I am going to setup some changes to the rig mounting. I have 3D printed side rails with a bottom feature for a 1/4″-20 attachment. I can strap the tuner to the rig via the rails and mount the whole thing on a mini-tripod. This will allow me better access to the rig controls and keep the wiring at the back from banging against the operating table. I’ll post some pictures when I have this completed.
This setup runs quite well and provides all the features I am looking for with a field activation. Next up…part Two: similar setup using the Xiegu G90.
I completed and deployed the 44-foot doublet antenna yesterday and have been running WSPR receive testing on multiple bands for just under 24 hours now. The antenna is in an inverted-V configuration with the feedpoint at about 10m height. It is fed with 50 feet of window line to a 4:1 balun. A 6-foot piece of RG-58 coax takes it into the shack and to the autotuner.
The antenna tunes on 40m, 20m, 15m & 10m. 20m is right at a 2:1 SWR all others are well below. I have the antenna broadside oriented slightly east of North. WSPR receive performance has been quite good and as predicated on these bands:
The total number of unique spots for each band is quite healthy. As predicted, 40m is a cloud burner with most contacts being regional although a few DX spots still managed to show up. This could make a very good Field Day antenna as noted by the North American spot coverage. I’ll try some QRP FT-8 and Phone on this later today.
I have all the components ready for the three band fan dipole. All I need is to cut the wire elements and assemble. This weekend I cut a section off the Aluminum “L” that supports my Spiderpole mast and reinstalled it. All this and yet I still have not completed the fan dipole.
I saw a brief article on the ARRL “On the Air” magazine about the multi-band doublet antenna. This is essentially a dipole that is not resonant on any band and feed with either window or ladder line. The end of the transmission line is connected to a tuner or a balanced to unbalanced 4:1 balun and then to the tuner with a short piece of coax. Looking at this a bit further, I found a post by WB3GCK related to his experience with the doublet. He posts to an L.B. Cebik article on a variant that is 44 feet long which should provide consistent directionality across 40-10m. With this in hand I ordered 50 fet of 450 Ohm Window line and a LDG 4:1 balun kit both off of Ebay. I found an appropriate center design on Thingiverse and just designed and printed an adapter that allows me to suspend it at the 10m point on my Spiderpole. I am about halfway through the Balun build so should be ready to test this week in an inverted-V configuration. Here are the parts:
This antenna may prove to be a winner for Field Day from my QTH in South Texas. For my QTH I want to cover all points North. Here is some modeling results:
Aside from these experiments, I am also queuing up additional tests of the Magnetic Loop Antenna, the HF Moxon & Hexbeam designs and a revisit of the trapped dipole inverted-V beam. Time is short and the days are now longer (and Hotter!) with Field Day up in about a month. Solar conditions are stronger than anyone really expected. I was making 15m FT-8 DX contacts last night at 10pm local time! This really opens the field to the higher frequency bands and antennas that support them.
Adventures in Amateur Radio 