Raccoon creek WMA POTA with the sBitx V3 SDR transceiver

Today saw me head over to Alabama to activate a nearby park that I have never been to before. Us-9875 Raccoon Creek Wildlife Management Area is a beautiful place right on the Tennessee river between Stevenson Alabama and Flat Rock Alabama.

I drive over to the WMA and find no one there at all, this is awesome as I like it when I have the place to myself. It gives me the freedom to setup the radio anywhere or in any manner I choose without having to worry about people walking into the radials or anything like that. Well, I get there and promptly decide to setup on 20 meters as I wanted to not spend a lot of time today activating as I wanted to also record a YouTube video for our brand new channel about amateur radio as well as have time to enter and upload the log from today and edit the video once I got back home.

If you want to see the video I made when I did this activation, the link is here. I didn’t film the whole activation, but rather pulled segments in and just did some of it, so you might be in it and you might not…lol. If people want the whole activation recorded in all it’s lengthy glory, I am not opposed to doing that, but I will need to hear that from the people…

When I want to do FT8 in the field I always grab this radio. The sBitx V3 is an SDR that is built around a Raspberry Pi SBC and uses a touchscreen for most functions. It only has two input devices on the radio, the VFO knob which never changes and the multi-function knob which literally can be used to adjust everything else…literally. It does have ports for a CW key, headphones, and a microphone on the side right above the power switch too. Since it uses a RPi4, it can be driven with a mouse and keyboard and during this activation I use the mouse to select FT8 stations to call. It is really handy for that. I find that if I am simply entering a call sign to chase on FT* I can use the built in keyboard instead of taking a separate keyboard. Another thing it has is Bluetooth, so Bluetooth devices will work on it too…such as a keyboard… I really like this radio if you have not figured that out yet.

Propagation was all over the place today as you can see on the beacon report above that I was weak at -19dB into “3” land but just a half hour earlier I was able to work JI3MJK in Japan! That is almost 7000 miles away!!! So if your activating and it seems like no one can hear you and you are about to give up, I would recommend that you give it another half hour, if possible, as the system might flip in your favor! That is what happened today.

I grabbed this photo below of the screen during boot up, it shows the OS version which is JJ’s 64 bit version 3.025 and that it knows who I am and where I have set the GRID to. This is important if you are doing POTA as you need to communicate that when you work FT8 at some distant location. The FT8 community is really into grids and want to collect them all…so pay attention to your grid. It is also showing the FT8 stations as they come in as well below that in green letters. Fortunately, it is really easy to change the grid on the sBitx so you dont have to worry too much about it.

So I setup in the truck and to be honest about it, I am really starting to like this concept. I am in the shade for the most part, if I am running FT8 only, I can run the engine and have AIR CONDITIONING at my POTA operation!!! Can we say WINNING!!! Ha Ha… I have done that once so far when I was in Florida if memory serves me but I would have to check. Using CW is a little tougher though. The diesel engine is loud enough to make copy of weak stations really hard so I don’t run it if I am working CW.

I normally try to work some CW though as I really love the mode so I normally will roll down all the windows in the summer and put my windshield sun protector in the window and work a bunch of those CW ops if the bands permit it.

A neat little addendum to the sBitx radio is that since it is driven by a Raspberry Pi 4, it can use a mouse and keyboard if you prefer it. Supposedly it has keyboard CW character generation too, but I have not attempted to do that yet. So if you are not able to send very well, this might be a solution for you. The mouse makes it much easier to choose stations that are calling CQ so you can pick them out on your end and you are not obligated to just call and answer CQ calls yourself. Farhan put a lot of thought into this radio and it shows.

Here is a little discussed subject…extra gear. I know we all take it with us but what do you normally carry with you when you go into the field? I have done POTA long enough now that I have sorted it out to just what I need and some redundant spares of failure prone items. Things like extra coax and another antenna are always in the spare tote.

The location that I setup at did have a really nice view of the river. This location is right next to the John Snodgrass bridge. This is the bridge over the river for Alabama Highway 117 to Stevenson.

As you can see from the logbook, there was a great run on 20 meters CW then another great run on FT8 as well! I even netted a J call on FT8! What a great day to do radio and the weather was great to boot.

Finally got my sBitx V2 radio…so I went to a park!!!

Quick synopsis is I like it. Read on to see why.

When you see this radio, you think it is like one of the big name machines. It is not. It is actually so much more because of the nature of the project that it comes from.

The HF Signals sBitx V2 is an evolution in their radio designs and brings so much to the table that is cant be described in one blog post…well maybe…I can write as much as I want in one post…lol.

The TR-35’s magic is the lack of menus.

The first thing you notice it the lack of buttons or switches like my Penntek TR-35 has on it in the photo above. There are simply two knobs and a display and that is all you are greeted with at first glance.

Well this is a kind of sleight of hand trick as the display is actually a touch screen and almost all of the controls are driven from this display. In fact, what appears to be at AF Gain (volume) knob, is actually like the multi-function knob on my Ten Tec Omni 7 being selectable for an array of things it can control.

Both knobs are also push buttons and the smaller one defaults to volume control if pressed, but the larger (VFO) knob doesnt appear to do anything when pressed, I can not find anything in the literature describing it so it is there for tinkerers from what I gather. You see, this is an open source SDR, this menas you can download the source code and if you are savvy with coding, you can add features or modify how the radio works to suit you. This is the point of the whole project to be quite honest. This radio does work, but it is not as polished as a big brand machine as it is intended for the owner to go inside and play with things, like add circuits or modify existing ones or even write new features to add to the radio outright. You can literally download the schematic and the actual source code from their GitHub… What ever you want to do, this radio is fully “unlocked” so that you can do it.

Enough about the radio in general, how did it do on the first outing to a POTA park? Well, it did really well, I did power it from the truck battery which means I had to setup in the truck somewhere so the power cable would reach the connection I have in the truck. (I finally added a power pole cable inside the truck cable that is fed directly from the batteries so losses are a minimum.

Back to what I was saying, I got to K-2169 and setup in the truck so I have somewhere to sit this time as I planned to stay a while today and didn’t want to have to stand up the whole time. It took me a few minutes to get it all organized, but once I did, everything fit quite well. I wanted to use my N3ZN key, but to be honest, this arrangement literally made it impossible, so I defaulted to the little travel key I have used so much over the last year. I didn’t have a table top that was convenient to setup the other key on and I even tried to sit the N3ZN key on my clipboard, but it was just too difficult and I kept running into problems trying to use it. Hence you see the Gemini cw paddle in my hand for this activation.

Once I settled on the key and radio, I chose 15 meters to get on the air, the band was wide open and even the propagation report said it would do well… Well, FT8 was rocking pretty strong (I tend to use these guys for my beacon report on a band), so I move down into the CW area and start calling CQ…and I call and I call…and nothing. Seems either no one was on the band or they simply could not hear me. It did appear that the band was fading in and out pretty bad though as the RBN would give me a great report one minute and then it would go 3 minutes without a single update. So after what seemed like an eternity on 15 meters, calling CQ with no answers I caved and went down to 17 meters to see what I can scare up.

The hamstick collection at this point. 15 (Green), 17 (Brown), 20 (Yellow), 30 (Blue) & 40 meters (Red) are all represented here (well, 30 meters was on the truck when I took this photo)

So since I had not edited the memories in the sBitx V2 yet for my use, I planned to use the PICO Keyer I picked up a while back, well it worked somewhat, I think it had trouble keying the radio because the radio is looking for contact closure and not a semiconductor so it would work, but it was introducing errors into the code pretty bad. I finally threw in the towel and just used the key the whole time and ran with it. This turned out to work really well though and I really didn’t mind it after all. Once I got home I built a complete set of memories for the keyer complete with all sorts of messages. You get as many memories as you want, they are in sets of twelve, I tested this by copying the CW1 memory and renaming it then I edited the messages and saved it, rebooted the radio (just as a precaution) and the new set of messages were right there in the drop down menu! They are really simple to edit, but you need a keyboard to do it. I didn’t take one with me on this trip hence I didn’t bother with trying till I got back home. If there is demand for it, I will detail how I added a memory and show how to edit the messages and the message names as well.

So I ended up using almost 4 Amp Hours of energy on this activation. Not bad for over 50 contacts in the log. I am happy with that! When I am going to be at the park for a while, I will get all the antennas out and sort them by band like you see below. Well, they are not sorted at this point, but imagine that they are for the story. Then I can change bands quickly and easily as I will lay them near the mount for the truck. The 2” PVC pipe is maxed out too. I don’t think I can get another antenna in it at this point. If you plan to run hamsticks, I recommend that you get some sort of tube to store them in to protect them. They are not very durable in construction so it would be best to try to store them in a way that will make them last.

You see, I know the radio is transmitting as I have been using it at home for the past week or so before taking it to the field. So I get down to 17 meters, find a clear frequency and start calling CQ here. Well things pick up for me here as I get a few answers so I know the radio is in fact working as it should and I didnt do something to it while I had it taken apart… More on that later when I talk about the mods I did to this radio right out of the box.

So after messing around on 17 for a few minutes I hit a dead spot, so I figure it is a good time to QSY down to 20 meters and see what I can find down there. Well, I found all the ham radio ops in the United States and some from across the Atlantic too! I proceed to make over FOURTY contacts in an almost continuous stream in about as many minutes! I was busy! The radio was working great too. At this point, I clear all the callers and decide to try the lower bands for a minute and see what I can do there.

So I hop on 40 meters first as this antenna has consistently been on the upper edge of SWR for my operating preferences, and the sBitx agreed with it showing about 2.1:1 while I was there. Also of note is that the radio self adjusts the output power based on band and SWR from what I can tell. I was running about 20 or so watts on 20 meters and wihtout changing the power setting at all, jumping on 40 meters netted me 9 watts output into the 2.1:1 SWR where on 20 meters I think the SWR was closer to 1.2:1… So I turned up the drive some in an attempt to get the power out consistent across the whole activation. I didnt get it past 15 watts if I remember right… But it was enough to make a few contacts and get some in the log from more local hams as the 20 meter band hops right over the closer states.

Then I finally moved up to 30 meters to see what it could do as well since that was the only antenna I had not tried yet. Well, 30 meters also did not let me down…like 15 meters did… haha. I got it on the band with good SWR and output power and easily made several QSOs on that band to finish up the HF portion of this activation.

The next part is just for fun, but I also recently got a new HT (Handy Talky) radio and was playing with it while out on this day. So I called into the KG4WBI/R 1.25m repeater to see if Roger was monitoring and he was. So then I asked him to switch his radio to VFO and simplex so we could make a 1.25m FM UHF contact. 5 watts was more than enough to make the trip the roughly 3 or so miles it was to his house from my location! So I netted 54 contacts on this day on 5 bands and two modes. I had a great activation and the sBitx pulled quite a long shift on it’s first outing.

Now to discuss some issues I found with the new radio that I am going to look into solving or upgrading. The first one is actually really easy, it needs a fan… or two. The heat sink got SO hot in the two hours I was in the field operating at about 20 to 25 watts. REALLY hot, the whole radio was hot actually and I think this is what made it start doing the next issue..

This is something I noticed after a while, when the radio is getting really warm, it starts to “stutter” in the refresh rate of the screen. I am thinking this is due to thermal throttling of the Raspberry Pi processor in an attempt to prevent sudden death from overheating. I confirmed this was not due to ram overflow by swapping the Pi out with a second one I own that has 8GB of onboard ram and it did it too with minimal use “on the air” back in the shack at home. So my solution is two fold, one is to install a fan on the main heatsink for the power amplifier in the RF deck and a second fan pulling air through the radio chassis where the Pi is located in an attempt to cool the processor as well. I know this will increase current draw from the battery, but I am not concerned with this as my activations normally don’t run over two hours at a time and this limits amp hour usage to usually no more than 3 or 4 amp hours, which even my smaller battery can handle at this time. If adding the fans runs the draw up to 5 amp hours or even 10 in an activation, then I will just take a bigger battery since this is not a backpacking radio in my book. Also, it did work at 25 watts down to 15 watts, depending on band and SWR, for the whole activation. If I were to just turn the power down to 5 watts, it probably wouldn’t get warm enough to matter on the power amplifier considering the size of the heat sink on it. This means I will probably install a small toggle switch to manually cut the power to the fans should I want to run it at true QRP levels in the field. I also plan to wire the fans through a circuit that will automatically turn them on and off as needed to prevent them from just drinking the battery dry when they are not needed. This involves a small temperature sensitive resistor called a thermistor in a voltage divider and a transistor to flow current to the fan. This way if the radio doesn’t get very hot, it wont come on at all. I think I did the math on this device and it will bias the transistor base at about 105F degrees, which is about right for it to protect the electronics. The processor cooling fan could be done the same way (and probably will) but I don’t want this fan to be very large so I am searching for a small 12 VDC fan for this application and also I want to see if I have room to install the processor heatsink, which is not currently installed. This alone will help tremendously, but with long activations the heat will eventually soak the heatsink and we will be right back to square one. This is why I want to add forced air flow to the system…

Even with all the heat buildup, the radio trucked right along and I put over 50 contacts in the log on the first outing! I even got some from overseas in the log!!! It is always good to get some DX in the logbook. I really liked this radio for a station that will be near the truck. The reason for this is that it is fairly large and heavy compared to my other radios, well maybe the Argonaut 5 is similar in weight. This is one of the reasons the Argonaut 5 doesn’t go on activations that stray far from the vehicle too. That guy is heavy, and it is a fairly fragile radio like the sBitx V2. So who knows what I will end up using it for, but for now, it will be one of my POTA radios.

All that aside, the radio works really well for the most part and over time this will be a wonderful little rig to run on activaitons. I plan to get it going on digital modes as well so I can work contacts on FT8, PSK31 and RTTY as well since it does all those modes natively and without the need for an external computer. This was one of the main reasons for getting this radio, I really didn’t want to have to bring an additional computer to the field to do digital modes… Anyway, with all that said, I packed up and on the way out found a few deer wandering around the area and I was able to get a photo of one of them. That was just icing on the cake for a day with so much activity and fun and getting to use my new radio. So until next week, get your radio out and go make a contact with it!

Activating a park on the side of the road.

I have been here before but never setup like this. K-0716 has park boundaries in both Georgia as well as Tennessee. I have activated both states with this park and have found this to be a great spot for a simple activation when time is short since the pull-off area is inside the park boundary itself. There is also a parking lot at the top of the quarry too and I will use it next time as I think it will be a little bit less exposed as well as I think I can get a wire up in a tree there. This location is called Eagles Nest and is a rock quarry probably used when the old Wauhatchie road was built back in the day, I couldn’t find any reference to the name of the place online, but it has this huge NPS sign so it is a thing…lol.

Today saw use of my trusty 20 meter ham-stick and the single 20 meter tuned counterpoise wire. I ran the counterpoise over to a large rock and draped the weight over it so that it kept the wire taught. This made setup pretty fast and simple, I was on the air in no time really. Although I did start out with the external speaker on my power pack for audio, I quickly realized the error of my way as the traffic was going by on the other side of the truck and made copy difficult at best. So I switched to my ear-buds and suddenly was able to copy all sorts of stations I couldn’t hear before!

I am pretty sure this forms an elevated counterpoise system and makes the antenna work better than laying the counterpoise on the ground…

The station today was setup in the rear floorboard of the truck and I was using the power pack I built containing a 3Ah Bioenno battery. I just used it to prop up the radio so I could see the display are reach the Aux switch for memory keying.

There was a little QSB on the bands today, but for the most part they were open really good, I was able to get runs of 10 minutes at times with strong signals coming in and I was even getting decent reports back to me. for the most part. But what was strange was that after I worked N9EDL it was like the band just closed or something, I called CQ for 10 or 15 minutes without so much as a peep coming back to me. It was like someone just turned the switch off… Then again the last 5 or so in the log are starting to spread out more than the previous contacts so it might have just been a deep null in propagation and if I had stuck it out it would have come back.

I took that as time to close up shop though and shut down the radio and packed it all up. It was a great little activation and I had a great time doing it even with the traffic on the other side of the truck. Good quality headphones saved the day here, so that is the lesson from this trip. Until next time. 72 de WK4DS

Monte Sano State Park POTA Activation AAR with a 20m Hamstick

Well, I finally activated a park in a new state… Alabama. You might think this is normal, till you google my address and see that I live on the Alabama state line in Georgia! I am literally two minutes by car from the state line and it took me several months to activate a park in Alabama… Anyway, I decided to activate the [sarcasm]remote and rarely visited[/sarcasm] Monte Sano State Park K-1048!!! Woohoo! Well. it is neither rare nor remote actually being literally minutes outside of Huntsville AL. It was new for me so I packed up the TR-35 and the new 20m Hamstick setup and struck out for Huntsville.

As fate would have it, I had business meetings that were on a time table so I didnt have a long time to stay, I thought once again that if I get my ten contacts I will be happy, well…I got more.

This is the QSO map from this trip. The VERY FIRST contact was with France!!! I thought, this is going to be a good day. Any day that my 5 watts reaches across the Atlantic Ocean, is a good day for me. It is obvious that the band and take off angle of my antenna dictate a certain “minimum” distance that people can hear me. A quick look at the map shows this, but just outside of this region and all bets are off! They piled in and in just over an hour I had 43 contacts in the log, with one being a dupe… It never ceases to amaze me at how well these little radios can perform with some thought and patience, but today the whole patience thing was out the window!!! I just kept getting calls! It was a QRP dream activation, I just wished I had been able to stay longer to see how many more I could have worked… Seems here lately, I am only able to stay and hour or two at best, I hope to remedy this soon, but for now, I will take that!!!

I also worked CU3AA in the Azores and VE2WLD (who also performed double duty as a Park to Park as well) for three DX stations on this trip alone! That is awesome and makes the whole activation just that much more special to me. If you have not ever tried POTA, I would recommend it at least once, it might not be for you, but if you enjoy setting up for field day, then you will probably like this. It is similar, but much more relaxed and lower key… At least that is how I see it. I find myself getting on the air more as a hunter and as an activation now that I have activated. It is just plain fun to go to a park and operated with a battery for a while and answer the passerby question from time to time. Once again, you can see the band opening and closing like waves on the ocean (maybe more like the tide coming in as it is slower than waves breaking on the beach) in the signal reports in the log. I even had a couple of people tell me they had problems with QSB (fading of the signal) towards the end of the activation.

Also of note is that this park has a day use fee (see below), be prepared for it when you get there, they have an attendant at the entrance to collect this fee before you enter the park. Parks seem to have a lot of lattitube in how they collect these fees, I have seen honor system pay boxes as well as no fees at all (Booker T Washington in Chattanooga TN has no fee) and then places like Monte Sano where they collect the fee at the entrance to the park. Cloudland has the honor system boxes as well as a attendant that works at the entrance part time, so you might find a person at the entrance and you might not, it is kind of a crap shoot with this one. You just never know… What I do know is the fee structure is normally really reasonable and to be honest…cheap for what you get. I bought my Georgia park pass back after my first activation and now that I am 47 activations in, that cost average is almost down to 1$ per visit. Once I break 50 it will be less than 1$ per trip. That is a smokin deal if you will be doing POTA ops regulaly at your local state parks (and they offer an annual pass like this one in Georgia). I plan to get over 100 activations at Cloudland before I have to renew my pass next May so then the daily cost should hit 50 cents per visit. Where else can you get a deal that good?

This is the only thing I brought back from that trip aside from my logbook, I don’t know how I forgot to get photos of the setup for you guys…I straight dropped the ball on that one. I guess it means I get to go back at some point so I can properly photograph it. LOL

The Penntek TR-35 is really starting to grow on me. This little radio just plain works. It doesn’t have things like a waterfall display or QSO recording like my IC-705 but what is does have is pretty much CW perfection. I have every control I normally use when doing an activation, at my fingertips and not buried in a sub menu or an alternate function for commonly used features…like CW speed control is a dedicated knob, this is super handy as POTA hunters vary in speed a good bit so being able to slow down on the fly for a slower op and then speed back up for a faster one is really handy. It is being tested out for a potential trip to Central America in a few months so I hope to keep up on using it and to prove it out as a capable machine while I am south of the border.

All in all it was a great trip and I finally got to activate Alabama too! If you have not used CW and want to, there are lots of ways to learn this historical mode fairly easily. It isn’t for everyone, just like SSTV isn’t for everyone, so if you don’t like CW it is all good, that is why we have different modes, at least in my mind it is, lol. If you have not done it yet, please like this blog and subscribe for future posts, Till next time, get your radio out and make some contacts!