I’ve been playing a fair bit of radio lately. What I haven’t been doing is working on any electronics projects or posting (obviously). Since starting my new job I haven’t had the mental energy to work on personal projects after an 8 hour day. I’m starting to get settled in now and can feel that starting to change. I fired up the transverter and K2 this evening and unfortunately the transverter didn’t come up. Let the troubleshooting begin!
In other radio related news I picked up a new amplifier right before the ARRL DX SSB contest. It was a lot of fun working some of those stations on the first call. I ended up with 175 Qs without really getting after it. I’d just cruise up and down the bandmap for the most part. I got a couple new DXCC entities and filled quite a few DXCC band slots (10 so far in LoTW). Here is what the operating position looks like now:
I hope to be posting more frequently again and will certainly post what the issue was with the transverter once I find it. 73 for now!
Since the video I got things all tidied up and reassembled. I also just received the replacement power regulator for the transverter. With any luck I’ll be smoke testing the transverter tomorrow!
Not related to my EME project but this one has been waiting in the wings for a little while. This is a rotor control board so i can rotate my hexbeam antenna from software. The build went pretty quick. This build was a little more involved as far as looking up part values and consulting a diagram in the documentation vs having a silkscreen. The service tool connects and makes the relays click so now I just need to wire it into the control box. I think that will be tomorrow’s project.
A while back I purchased a GPS Disciplined Oscillator (GPSDO) off of ebay. The idea here is that this device receives the GPS signal and from the 1pps signal it can generate a very accurate 10MHz reference signal. This can be useful to ensure your transmitter isn’t drifting with temperature fluctuations. I hope to eventually pipe this into a PLL circuit to get 116MHz and make that the local oscillator for the transverter like these guys did.
I was pretty shredded after work yesterday and didn’t feel much like soldering so I dug this thing out to play around with. The unit I received is an older Thunderbolt by Trimble. Apparently a large number of these were ripped out of cell tower sites and are now available on the surplus market. Lucky us! After figuring out which serial port it was hanging off and editing the heather.cfg file I fired up the Lady Heather application written by KE5FX.
This is a pretty neat application and will provide some additional functionality when operating EME in the field. You can see right in the middle of the screen is the azimuth and elevation of the moon. You can display this in wsjt-x as well but I’m not sure if that is dependent on an internet connection at all. Either way a second source doesn’t hurt.
The other more important piece of this and maybe even more important than the disciplined oscillator is that this device can update the system time of the computer. Obviously timing is important when it comes to JT modes and almost certainly QRA as well. According to the readme file it’s not an elegant way of updating the system time but it works (when it’s running as administrator on Windows 10).
After letting the device acquire a GPS lock and settle down I hooked it up to the frequency counter.
I’m not sure what kind of accuracy I should be expecting but this is probably good enough for government work. I’ll most likely end up getting an active GPS antenna even though the tiny patch antenna i’m using indoors seems to be fine.
I’m still waiting for my wife to notice the new icon on my desktop:
Get it? Disciplined Oscillator!
I also printed off a holder for my soldering tips!
This was one of my first successful electronics projects a few years ago. It’s a TNC-PI from Coastal Chip Works. It’s basically a packet radio interface that sits on top of a Raspberry Pi. I built this thing several years ago and managed to digipeat a few signals off of the ISS as it passed over. I’ve always wanted an enclosure for this thing so when I found a design it helped push me over the edge in buying the 3D printer.
I can’t remember where my packets were gated out but I did manage to log the first ISS packets received on this thing. May 30th 2014
1: fm N7HQB to CQ via RS0ISS* ctl UI^ pid=F0(Text) len 53
0000 =4038.2604N/11155.9874W-DN40AP- HELLO FROM SLC UTAH!.
1: fm N7HQB to CQ via RS0ISS* ctl UI^ pid=F0(Text) len 29
0000 HELLO TO THE CREW ON THE ISS.
I’m printing a holder for my soldering iron tips at the moment and I might kick off a print of a BitX40 case this weekend. Hopefully I can find some time to do some soldering between now and then!
I haven’t had much time to spend on the 3d printer lately. I had a laundry list of minor repairs and was having some issues getting prints to turn out. Unfortunately ignoring it did not seem to make these issues go away so this past weekend I got to work.
I replaced the print cooling fan and printed a new duct for it. This seemed to help but I was still getting really stringy prints. It would also occasionally drop these weird brown discolored clumps on the print. This ultimately turned out to bee filament oozing out of the hot end. Replacing the tube and the nozzle seemed to alleviate these issues. Just for good measure I switched filament spools from the cheap Chinese stuff to the cheap American stuff made by Inland i believe.
Once I got things in working order I turned my attention to creating some functional prints.
This is an VHF yagi antenna insulator. I found these files on remoteqth.com. You can see how they are used HERE. I’m hoping these can be used when i get to the point of building my portable EME antenna. You might notice on the remoteqth page that they show this model printed out in a variety of sizes. I sent an email to Dan OK1HRA asking about the availability of the other models. He responded by asking me what sizes I needed and that he would just plug that into openSCAD and generate them instantly. I had to see what this was all about so I downloaded the application.
Dan had the source for the model posted HERE. After pasting that in the left hand pane the model popped up on the right after pressing F5. You can see in the source that there is a section called input parameters. Modifying any of these and pressing F5 again will recreate the model with the requested change but it will also scale the rest of the model to accommodate said change! Now i can make the insulator to suit what ever material I end up using to build this monster. Which will surely be easier than finding metric aluminum stock up in the mountains.
In the process of printing out a few of these insulators for testing the connector on the heat bed fried.
According to the internet this isn’t an uncommon thing with these Anets. I cut that connector off and just soldered everything directly onto the heatbed. I also upgraded the power cables to 14GA instead of what the kit came with which was considerably underrated. It seems like it’s always something with this machine but it really forces you to think about what is happening (or not) when things go wrong. I think this will serve me well in the long run if I ever decided to get a better printer.
Oh and i also made some more progress on the transverter. You can see that most of the passives as well as all of the relays are done. I’m nearly done with the base build of this thing. After this I think I’ll be building the rotor control board before moving on to the 144Mhz specific phase of the build.
I finished all of the resistors and some of the diodes for the base transverter tonight. I think I’ve decided to finish the base unit before i start on the rotor controller. That will be a natural stopping point since I haven’t done an inventory of the 144Mhz specific components yet.