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Winter Field Day 2023 After Action Report

New/Upgrades for WFD 2023:

Failures:

Two failures were noted this year. First, I found a coax jumper with a bad BNC connector on one end. This was overcome by grabbing a backup jumper. The second was missing cordage as noted in the Go Bag section. Other things were not a failure per se but could be improved as noted below.

Weather:

It almost feels like we cheated WFD this year. The weather was cool at 33°F when I arrived at 0800. By the afternoon it had warmed to 60°F and full sunshine. Late in the afternoon, clouds began to move in and by 1900 we were getting spotty showers. The showers turned into a full on rain event overnight that continued through Sunday morning. Around 1000 there was a break in the rain with intermittent showers continuing for the duration of the event.

General Notes:

A total of three radios were used this year. The primary station used the Icom 705 and the Evolve laptop for JS8Call, Winlink, and a few voice contacts. Band conditions were good. This entire setup was run from the RV battery. See Battery & Solar below

The second station was an APRS digipeater.

The third radio was the Yaesu FT5d carried on my person for comms around the FD site.

I participated in both the APRS and Winlink challenge managing many contacts with both. In addition I worked a few phone contacts early Sunday morning on 40M as well as contacts using JS8Call on 40M.

Several Winlink RF connections were made. All Winlink connections were made using HF frequencies and the 705. These connections were made exclusively using VARA and the connection speeds were some of the best I have ever seen. Winlink was used to make contacts, post position reports, pull other's position reports, pull APRS data, and get a weather forecast.

Additionally, FLDIGI was utilized to download a weather map and a weather satellite image as described in this video. Both of these were loaded onto the Pi Display.

The Evolve laptop, which was new for WFD, performed every bit as well as the Pi has performed in the past. The only thing found lacking was some reference material that didn't get transferred to the new system. While it didn't cause issues, it should be loaded onto the system.

APRS Digipeater:

The digipeater was run with a Pi 4 and a Yaesu FT65r connected to a Mobilinkd TNC 3. The FT65 required one battery swap late in the evening on Saturday. The dead battery was placed on charge using the cradle and a cable that could be plugged into a 12V source. The second battery for the radio lasted until early Sunday morning before it was swapped again. The Moblinkd battery lasted for the duration of WFD. The Pi for the digipeater was connected to the TV in the RV giving a nice display of the APRS map for visitors. The digipeater was NOT connected to the internet. With a roll up J-Pole at ~25 feet, it was heard by the wide area digipeater/igate (W1ARN) without issue. This Pi was powered from one of the RV 110V circuits. See Final Conclusions

It would be worth exploring a couple of things to do different with the digipeater. This could be run with a Pi zero which only runs dire wolf without a GUI interface. This would require use of the Digirig sound card. The advantage would be lower power consumption. The disadvantage would be the potential loss of the APRS maps. A work around to the map would be to connect to direwolf over the network (TCP) and display the map on the primary work station (running YAAC) which could be connected to the TV in the RV via HDMI.

Pi Display:

The Pi Display was a HUGE success. Other hams and visitors to the site stopped to read the display. Many commented on the contents being displayed. It was well worth the effort to maintain the display and it should be incorporated into summer field day plans. The only downside observed was it was a bit difficult to see in direct sun. If kept angled away from the sun it was OK. Some amount of shade could be deployed to help with viewing.

For future outings, this should be powered from the solar on the side port instead of using the 110V outlets on the outside of the RV.

Solar & Battery

Consumption Notes
RV TV - 2A
RV Heater Fan - 2A
- The RV is heated with propane but it requires a 12V fan to circulate the warm air
Each RV light - .5A
RV 12V Fridge - ~2.5A when compressor is running
APRS Pi - 350mA
Pi Display - 700mA
705 & Evolve - 600mA on receive

The entire setup this year, both RV & all radio equipment, was powered with the 100AH LiFePO4 battery that was upgraded in the RV last year. Some equipment used 110V outlets which required the inverter to be used. In addition to the 290W of solar on the roof, I carried a supplemental 60W folding panel that was connected to the Solar on the Side port of the RV. Solar on the Side is a direct connect to the battery. As such, it can be utilized as a 12V power port but this also means that any solar connection requires a solar charge controller. I used the Genasun MPPT controller that I already had on hand when connecting the additional panel.

Early on Saturday with everything running in the RV and all of the radio equipment operational, I was losing ~2A of power from the battery each hour due to the low angle of the sun. Once the 60W panel was connected and pointed at the sun, I was gaining ~1.5A each hour. I continued to move the 60W panel throughout the day for optimal output. The total 350W solar input resulted in the RV battery remaining at 100% until the cloud cover moved in late in the afternoon. After dark, I shut down anything possible to conserve battery power. This included the digipeater display running on the RV TV. The digipeater remained operational and was accessed via a VNC from the Evolve laptop. This saved ~2A of power each hour. The Pi Display was completely powered down and never returned to service. (See Final Conclusions) Lights were kept at a minimum in the RV and the heat was set to 68°F. When we broke down on Sunday, there was approximately 40% (40AH) remaining in the battery according to the shunt.

One thing to keep in mind is that the slide on the RV as well as the electric tongue jack require battery power. There needs to be enough left in the RV battery to operate these after the event or the generator will be required to power them.

Generator:

The generator was on hand as a backup power source but not utilized for WFD. Since WFD doesn't require the AC unit, the generator isn't needed the way it is during summer field day. For propane consumption while using the generator, see summer FD 2022 AAR

Propane:

A minimal amount of propane was required for heat and cooking. Roughly 10% of one 20lb tank was consumed during the event according to the Mopeka tank sensor. The RV heat was only utilized overnight due to the mild conditions during the day. Even so, there is plenty of propane on board to run the heat for the entire event.

Go-Bag:

Moving to a modular go bag proved once again to be a winner. When combined with the Checklist Generator, nothing was forgotten. The only thing that came up short was additional cordage needed to connect the end of the EFHW antenna to a tree. W0MET had extra that he loaned me. Without this, the wire could have been tied off to the ground but the performance may have suffered slightly.

Antennas:

Just like summer FD last year, my EFHW kit antenna was used for the HF antenna. A rollup J-pole was used for the digipeater. These two antennas have a proven track record of working well and being easy to setup requiring a fairly small footprint. There are no current plans to alter this setup.

Two TN07 masts were used to get the antennas in the air. It would be nice to attach both to the same mast. This could more than likely be accomplished with a small 3D printed part.

Final Conclusions

Things worked as expected and I was pleased with the overall RV battery performance. However, if there was not sunshine for most of Saturday, I am not sure the battery would have been able to keep up with all of the power demands for the ~30 hours of the event. It would have been close. The generator should always been on hand as a backup power source and power draw needs to be reduced whenever possible.

The Pi Display (Pi and external monitor) was powered by 110V circuits requiring the use of the RV inverter. This is less than ideal as power inverters are less efficient and consume some amount of power even when sitting idle. The Pi Display could get 12V power from the solar on the side port which would eliminate losses of the inverter. The Pi Display could possibly be run with a Pi zero which would reduce the power consumption. Some testing needs to be done! The display would probably be ok just running on Saturday and Saturday evening. There aren't enough visitors on Sunday to warrant running.

Similarly, the digipeater Pi was also powered by a 110V circuit. This could also be run from a Pi Zero which only consumes ~150mA. This would cut current power consumption by 50% compared to the Pi 4 and would be easy to run from an 8AH battery (.15A x 30 hours) without requiring a recharge. It would be more difficult to run the digipeater from the RV 12V power due to the location of the unit.

To-Do List:

Fix Coax Jumper BNC
Make up 12V power cord for Pi Display
Make up splitter for Solar on the Side port
Determine battery needed for Pi digipeater
JS8Call message challenge?
Add spare cordage to the RV storage
Convert digipeater to Pi Zero to reduce power consumption
Load reference material onto laptop
Explore sharing 705 GPS over the network with gpsd
- Do video on this!

END OF REPORT

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