Monthly Archives: May 2016

Battery Pack for Solar Station

I received four 12V, 6Ahr lead acid batteries that were excess to a local ham’s needs and I am looking making a portable battery pack for my solar station. Each battery is 3-1/2″x2-3/4″x 4″. In parallel, I can reliably get 12Ahr of capacity from these batteries at long life level (50% of total capacity of 24Ahr). What I am planning is to mount the four batteries into a plastic ammo box wired all in parallel. Into the box I will add two wattmeters, a solar charge controller and wire the outside with appropriate input/output connectors. With this I should be able to flick a switch to engage the batteries and then plug in my solar panel on one end and the load to the other. I may even put a 12V lighter socket and USB charger to it as well. In this way, I can get more battery capacity and isolate the radio gear from the heavier solar power supply. I may do something similar with the existing 7Ahr batteries and dedicate those to charging a laptop in an emergency. More to come on this but this should be a good project to have some backup power.

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Setup APRS Station

I finally broke down and bought a digital interface from Cliff, N5CEY that connects my Baofeng UV-5R to an iPhone. The iPhone is an older 4S model that is now retired after having been upgraded. It does not connect to a phone service but the WiFi and GPS work fine. I installed the Pocket Packet app and after a bit of fiddling with the radio and the app I started successfully sending APRS packets to the local digipeter.Mission accomplished as I now have a low cost dedicated APRS system to play with.

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?