Hinged Solar Panels

The 3D printed hinges I downloaded from Thingiverse didn’t fit my solar panels. Fortuantley the source for the design was done using a program called openscad. This is a unique cad program in that the models are not developed graphically. Instead you right a sort of script “code” which build up the solid model as a description. This came in handy for this project as I needed an additional 10mm of length on the hinge links. Here is the finished result ready now for field use:

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Initial 3D Printing Results

The Creality CR-10S is certainly living up to its great reviews. The fiddly bit is getting the bed level but once that is dialed in it appears to print very reliably. The leveling is important to get the first layer to stick well to the glass bed. I have also been using a wide brim on each piece to increase the contact area of the first layer. I printed four parts yesterday to form a hinge for my two solar panels:

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Next up was a holding bracket for my Koss SB-45 Headset. Here is the part being built on the printer:

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Here is the completed part:

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Mounting is via a piece of double sided carpet tape. Both of these models were downloaded from thingiverse.com which is a very large repository of printable items. Do a search for things like “ham radio” or “dipole” for some idea of the possibilities for the hobby.

Busy Summer!

It has been a busy summer this year. Work has been demanding with several international trips now behind me. Just finished up an active Fourth of July holiday that involved the beach and good family time. I missed field day activity this year and have just yesterday logged my first QSO’s in over two weeks. Things are settling down now and I am starting to work on some fun projects related to Ham radio. First up, I have an Arrow antenna on order for use in working the ham satellites. I actually ordered this some time ago but an item was back-ordered and so this has only just shipped yesterday. Looking forward to working the satellites soon!

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My next couple of projects are not truly ham radio projects but will assist many ham radio activities. I previously mentioned how my HP Z400 workstation had a hard drive that is failing. I decided to upgrade to a more powerful computer so I have ordered a used HP 620 workstation with dual Xeon processors for a total of 8-cores, 16GB of ram, dual 1TB hard drives and a Nvidia K4000 video card. I have been very impressed with the HP Z series workstations as they are very reliable. This computer will eventually replace the Z400 as my main machine. I’ll replace the drive on the Z400 and reload everything on it for use on my new 3D printer.

Yes, I bought a new Creality CR-10S 3D printer.

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This printer has gotten great reviews and is assembled in about an hour. I was an early adopter of 3D printing years before i got into ham radio. I had a Makerbot CupCake back then and enjoyed the technology but didn’t like the constant fiddling with the hardware to make it work. The machines are still a bit fiddly but my build volume is now 300x300x400mm! This machine can build a variety of very useful ham radio tools. Things like dipole centers, wire antenna insulators, small custom enclosures, power pole break-outs etc. As I type this post is it building up a set of brackets and hinges to tie together my two 15W solar panels which I use portable.

I no longer have the Makerbot machine but I do have a Rostock-mini Delta printer and a Prusa I3 that I had acquired used many years ago but never got working. I can use the new printer to make replacement parts for these machines and will see if I can get them working.

 

 

 

Listening to Ham Satellites

I have long wanted to try the amateur satellites. Back when I was a kid I had my trusty Allied receiver and my AO-7 tracking tool but try as I might I never picked up a signal. Today I loaded up the GoSatWatch app on my iPhone and started looking for passes with the aim to at least pick up a signal. There was a decent pass of AO-92 Fox-1D so I tuned by rig to 145.880 Mhz and turned off the squelch. Sure enough a few minutes after the pass started I began picking up signals from the satellite.  This was using my standard discone base antenna. The signals never got really strong but it was encouraging to know that the timing piece worked out well. You can guess what will be coming next…a handheld dual-band yagi.

20m Alive with DX Today!

20m phone band was wide open to Europe this afternoon at the QTH. Made several contacts on 100W SSB. The waterfall looked quite active with stations coming in from pretty much all over Europe and the Middle East. Interesting that the solar indices (SFI=68 & SSN=0)  do not suggest any improved activity. This could be a seasonal shift. I hope it shows up again tomorrow!

Where have I been?

The life thing has been pretty disctracting from ham radio the past few weeks. I just returned from a week long business trip to the Philippines and then had a bunch of catch up to do. This week I started making Field Day and Portable operation preps. I took out all my battery packs and charged them with the solar panels. All are ready to go now.

I ordered a cool little gizmo for the FT-817ND. It is a 3D printed power connector that fits nicely on the back of the radio and converts the power inputs to Anderson powerpoles. I got mine from Ebay:

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Regarding Field Day, I am still thinking about a 20m beam.  I’ll be doing some modeling comparing the Buddistick, the 2 element vertical beam and a 2 element, inverted-V wire beam. I have already built two of these three and have good results on QRP.

I tried some operating today but so far conditions have been…well they have been pretty bad. SFI=68 and SSN=0 makes for some pretty bad propagation. Definitely need to up the antenna game.

QRP Tests of the 2el Vertical Beam

Rainy day today.

I had planned to take down the vertical beam antenna today and send up the end fed half wave to test for possible field day use. So instead I have left the 2el vertical beam in place and cranked down the power on the IC-7300 to 5W on SSB. I frankly was not expecting much as band conditions have been awful on 20m. I called CQ for a minute or two and a portable station in North Carolina picked me up. We had a short QSO and I received a 59 signal report. Called CQ again and picked up a station in Georgia. I was having more trouble receiving than he was in hearing me. QSB on 20m is pretty bad sometimes. Made one more call and was picked up by a station in KS who gave me a 57. Made  these three contacts over 10 minutes on 5W.

There is hope for Field Day this Year!

miniVNA and Choke Measurements

I recently bought a miniVNA Pro analyzer:

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This is a pretty cool little device that goes beyond just analyzing antennas. One of the first tasks I set this to was measuring some ferrite chokes for comparison. The miniVNA makes quick work of this in transmission mode and in saving the data in Excel format. Here are choking impedance plots for three ferrite based chokes:

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In blue is 9 turns of RG-8X around two FT240-43 cores. This has the best choking performance. The orange plot is a 1:1 choke balun made from an ebay kit. The grey plot is an MFJ-915 line isolator.

2el Vertical Beam Antenna WSPR Results

I ran the 2el vertical beam antenna on 20m WSPR for most of the last week. This time I looked at the WSPR challenge data as compared to N5CEY’s station about 15 miles away. During the week we both made the WSPR challenge scoreboard. On some days I had a higher unique count while on others N5CEY did. The WSPR Challenge site provides a list of all the stations heard in a 24 hour period along with their counts. This can be downloaded and sorted to see which stations had the highest counts. The data for a specific station can then be downloaded over the time period. Here is the count comparison:

wspr challenge counts

Here is a plot of the reported SNR vs time to K8JBV in Ohio from both my station (red) and N5CEY (blue):

WSPR comp

This chart is fairly typical and shows that N5CEY has about a 6dB higher SNR at his station vs. mine. I did note at least two stations, one in Georgia and the other in Florida, that had SNR roughly equal at the two receiving stations. This correlates well with the direction I have the vertical beam pointed. Likewise stations on the backside of the beam have a  few dB more separation.

I am pretty happy with the performance of the vertical beam antenna overall. What I would like to do next is operate portable from a more rural location and measure and differences in SNR on WSPR.

Update on the 2el Vertical Beam

I guyed the antenna elements after finding it survived the night. here is a view of the antenna:

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I know it’s hard to view but the elements are there. 😉

This antenna is working very well and has scored the past couple of days into the top 25 in the 20m WSPR challenge.