Let’s take a look at hamstick antennas and see how they perform without tuning the counterpoise for each band.
No POTA outing is complete without some good ole McDonalds java to get you cranked up. I normally make my coffee at home but today I was in a bit of a hurry so I went through the drive through and picked up some of their magic water. Today I chose the Sittons Gulch parking lot at the bottom of the mountain as it is significantly closer to my home compared to the upper lot. Google Maps says it is a full 15 minute drive from one lot to the other. So operating from here gives me an additional 1/2 hour on the air. That is awesome.
So I setup the station in the truck today and learn a few things that I didn’t know before. One is that the power port on the dash I use is not great at carrying the load of a 20 watt radio. I can see the voltage dip to almost 11 volts on transmit. This is not good. So I opted to switch to the battery and get the voltage back to where it needs to be. This means that I now have another side project to fix this socket… But I am also going to install a direct power feed to the cab of the truck for my winter time ops so I can power the radio off of the truck batteries directly and install a anderson powerpole outlet inside the truck.
Today saw the battery deliver another 2 amp hours of supply, that is four total so far for the 8 amp hour cell. If I get 6 out of it at this point, I will be happy. It is over a year old at this point and it is still going strong. This is not some big name brand battery either but rather some cell I found on Amazon last year. It has seen many activations too. I used it heavily when I was using the Icom IC-705 and kept it in the backpack with the radio. Then when I transitioned to my Penntek TR-35 I used it with that radio for months. So this battery has seen a significant amount of use. I am impressed.
Another thing I have been doing is testing the antennas on the same set of radials (the set I tuned for 40/20 meters) and just switching out the vertical radiator only. I was pleasantly surprised at what I found out today to be quite honest.
Ham-stick antennas work shockingly well for what they are. So well in fact that I am about to go on a 10 park rover operation and use only the 20 meter ham stick (unless the band closes then I will move… lol) for the whole event. My strategy being that 20 meters is the most popular band by far so I should be able to get ten contacts at each park pretty easily. This should give me the best odds at completing my rove and making it to ten in one day. Below is the report from my nanoVNA showing each band I have a ham-stick for and just using the same counterpoise every time. (Side note here, I was also deploying the counterpoise differently too so as to keep them out of the way and this also affects the antenna, see the photo below there is a photo further down in the post showing them). The plots are arranged from the highest band to the lowest but after seeing the results, I don’t think it matters as I dont see a pattern to be honest.
15 meters kinda threw me for a loop. I need to trim the “stinger” some and push this one up into the band more. The null is actually at something like 20.250mhz so yeah, this one needs work. I didn’t have my cutters with me or I would have done it right then. Even so, the SWR was still low enough to get on the air and I was getting RBN reports as high as 20dB which is phenomenal for a 15 watt signal out of a ham-stick several hundred miles away…that is off-tune.
17 meters also caught me off guard. Look at that plot with radials tuned for 20 meters instead! Ft8 on this band will be epic! I have plans to start doing some digital modes during POTA outings in the future so I am happy to see this.
20 meters actually needs trimming too. I have known this for a while, but it is close enough for CW so I have not bothered yet. As you can see, at 14.060mhz on this day, with this radial arrangement, it was still less than 1.2:1SWR. I have had this particular radiator the longest out of my entire collection and bought it last year in anticipation of winter ops. Which it worked perfectly for me in that role. This is why I have slowly collected the set I have now. They just work.
30 meters is honestly the best looking lower band out of the three that I have. 20 is tuned low and 40 needs some help with more radials (most likely), but 30 meters lands just right, with the null point covering the whole band.
40 meters is odd to me. It works and has respectable SWR even with a poor radial field but I would like to see it even better if possible. I think this is more to do with the antenna design and poor counterpoise than anything else. The other bands work great but this one is just not that awesome and I am still sorting it out. Dont get me wrong, 1.46:1 SWR is great but I think it can be alot better. I just need to dial in the counterpoise or something. I am also going to setup another trace on smith chart to see if I am capacitive or inductive and not purely resistive. That might be part of the problem. The SWR plot is nice for simple and quick checks but there is more data to consider. More to come on this…
I did all my tests with the common mode choke installed so I would know what the radio actually is transmitting into. This way I dont get surprises along the way from things not being like they were when I did my test.
The logbook today looked good too. I didn’t have a long time to work the activation so I was happy to see 23 get into the log today. That is a good day for me. I was a little sad though since I was getting picked up on the RBN and could hear stations on 15 meters but no one could hear me… Oh well, maybe next time.
I messed up the sequence and had to correct it. Hence all the scribble in the margin… sorry about that.
Thanks for coming along on this after action report, hope to work you on the air soon!
72
WK4DS