February 2020 Satellite Operations Gear

To track things over time, I thought I’d do an overview of my satellite gear as of February 2020. I actually have two different setups for satellite operations: one for the FM/APRS sats and one for the linear transponder sats. Since I do FM sats much more often, I’ve tried to slim that setup down so I can quickly run out to catch a pass.

In both setups, my Kenwood TH-D74A serves as the receiving radio and APRS transceiver. This radio, while not full duplex like its brother the TH-D72A, it is a great option for satellite operations in a two-radio configuration. My favorite feature is the built-in audio recording function. This makes recording audio from satellite passes for later transcription a snap without a mess of additionally cabling and a dangling audio recorder. This radio also contains an APRS function which can be used with the ISS and other APRS satellites with just a couple configuration changes. Finally, this radio has a wideband all-mode receiver which lets it work for SSB on linear satellites. Of course, tuning is a bit tricky without a big knob, but it is doable. For FM sats, I simply hang it from a lanyard around my neck and use a 2.5mm mono to 3.5mm stereo audio adapter cable to connect it to earbuds. I also have all the FM sat frequencies programmed into memory so there is little preparation required for a particular pass.

For FM sats, my transmitting radio is typically the Ailunce HD1. This radio is dual band DMR/FM radio, which makes it versatile outside of sat operations and a way for me to keep my ham radio equipment list to a minimum (blasphemy, right?). There is nothing special about it other than it rated for 10W RF output which can be a nice extra boost when needed (like when using my Shorty Arrow).

Chest rig with Yaesu FT-817ND and Kenwood TH-D74

Chest rig with Yaesu FT-817ND and Kenwood TH-D74

For linear sats, my transmitting radio is the venerable Yaesu FT-817ND. It serves double duty as my QRP HF radio, so it is easy to bring my HF and sat setups together on trips. In order to make it a bit more user friendly for satellites, I’ve added a computer headset with a couple adapters and a handheld button for PTT. I also have made a chest rig made from dual-shoulder camera straps and two MOLLE pouches which hold the 817 and D74 at an angle for easy viewing. This works fine but I’d like something a bit more secure to hold the D74.

LidStick

My Arrow Antenna turned LidStick

The antenna I use is either my standard Arrow Antenna (modified into a LidStick) or my Shorty Arrow (also LidStickified). In 2019, the Mini Circuits BLP-200+  popped into my Twitter feed as Mike, W8LID (also the creator of the LidStick), found that it worked well to prevent desense that is sometimes experienced on certain satellites and radio combinations. This filter is put on the 2m driven element BNC connector, and in my experience, it has completely removed the desense issues I had. You may notice it has a 1/2W rating; Mike got in touch with Mini Circuits and learned that this is really only an issue for out of band signals. Many of us have consistently put 5-10W or more of 2m signals through the filter without any issues.

To travel with my Arrow Antenna, I use a telescopic plastic tube which is commonly used to transport real arrows or posters. It is fairly lightweight, but strong enough that I’ve put it in my checked bag many times and it has kept my antenna protected. It is large enough to fit the full size Arrow Antenna, my Shorty Arrow mast, and even my rubber duck antenna for my HT. For the price, this is an excellent option for transport and storage.

For coax cables, I currently use RG-58/U and LMR-240 UF jumpers with BNC connectors. I recommend staying away from cheap RG-58/U (I’m using it temporarily), but the LMR-240 UF is high quality stuff.

The last part of my setup is my iPhone 11. Nothing special about it, but it runs GoSatWatch as my main satellite tracking app. The app costs $9.99 on the App Store, but it is well worth it for any sat op. I really like that it uses the IMU in your phone so that you can hold your phone up to the sky and physically orient yourself to where the pass will be in augmented reality. It has a simple but nice user interface and can support more than just ham radio satellites.

Theodolite iOS App Camera View

Theodolite Camera View

The other app I use occasionally is Theodolite. Photos from this app are often posted to Twitter, leading many to ask “what app is that?” It is useful to see your exact position and error of the GPS and record that for those gridline and corners that require evidence. It is $5.99 but again, well worth it as it has many other features that you may find useful.

 

Shorty Arrow Satellite Antenna

Shorty Arrow Antenna

After seeing a few people on Twitter with a a shortened Arrow Antenna for satellite operations (colloquially called a “Shorty Arrow”), I decided to try to build my own. Rather than three elements on 2m and seven elements on 70cm as with the regular Arrow Antenna, the shorty arrow has two elements on 2m and four elements on 70cm. This results in a more compact and lightweight antenna at the expense of gain, particularly on 70cm. In my experience, this limits the antennas use down near the horizon¬†especially if you have foliage in the way, and it is definitely a bit more of a challenge to get into some sats. Still, I’ve made plenty of FM contacts using 5w radios and this antenna even on weekend passes. I particularly like using this setup when I travel somewhere via airplane as this is small enough to fit in a carry-on bag.

Since you’ll need the antenna elements anyway, I suggest you buy a full size Arrow if you don’t have one already and just share the elements between them. It also saves you having to bother with measuring and centering the holes you drill; just clamp the full sized Arrow to the shorty to drill like I describe below.

What you’ll need:
-2m driven element
-2m reflector element
-70cm driven element
-70cm reflector element
-70cm 1st director element
-70cm 2nd director element
approximately 2 feet of 3/4″ square aluminum tubing – I found four feet of this at Menards for around $10
-handgrip of some sort. I used a foam grip from a garden trowel I found at the dollar store

Tools:
11/64″ drill bit
-hack saw
-metal file
-hand drill
-a couple clamps

The build process is actually really simple and doesn’t require any measuring:

  1. Remove all the antenna elements and the hand grip from the full size Arrow Antenna.
  2. Take the square aluminum tubing and clamp it flush against the Arrow Antenna. Make sure you don’t place the clamps over any holes.
  3. Use the Arrow Antenna as a drill guide by drilling through its element holes and into the square aluminum tubing with the 11/64″ drill bit. This allows you to easily drill with the same spacing as the original Arrow Antenna without have to measure and center the holes. Do not drill through the holes that are usually hidden behind the hand grip on the Arrow Antenna – these are tapped for a 1/4-20 tripod mount.
  4. Remove the clamps, rotate the tubing and Arrow Antenna so the blank side of the tubing aligns with the other band’s element holes on the Arrow Antenna, re-clamp, and drill the holes for the other band in the same way.
  5. Using the hacksaw, cut the excess length off the aluminum tubing.
  6. Use a metal file to round off the ends of the tubing and remove any burs around the holes.
  7. Slide the hand grip on your new Shorty Arrow Antenna and install the elements.
  8. Go work some sats!

USB Quick Charge 2.0 Adapter for 12V Non-Quick Charge-Enabled Devices

As I got interested in roving more for satellite operations, I was looking for ways to slim down the equipment I needed to carry, particularly on trips that require a flight. While packing one night, I noticed I had a Tronsmart WC2F USB power adapter that supports the Qualcomm Quick Charge 2.0 protocol. This is one of several protocols that let devices use higher voltages and currents over a standard USB A connector. There are a few versions, but in short, this protocol allows for the USB power adapter to supply 12V at 1.5A, among other less interesting voltages (to me anyway). This seemed like a perfect way to charge my 12V devices – my Kenwood TH-D74, Ailunce HD-1, and Yaesu FT-817ND – without having to bring along an additional wall wart.

After digging a bit, I found an article on Hackaday where someone made a custom power adapter using Digispark, a modified regulator, and some simple handshaking code. Going down into the comments, Sam Mallicoat mentions the handshake can simply be done with a couple resistors and a momentary switch. Even better, Horst Leykam replied that a regular old latching SPST could work instead of a momentary switch. Aha! Since I was trying to keep this compact, this seemed like a great option compared to adding a microcontroller to the system. My plan was to made a cable adapter with an in-line switch that contained the resistors. A USB A male connector on one end and 2.1mm barrel connector on the other would give me good compatibility with my devices.

12V Enable Circuit for USB QuickCharge 2.0

For the switch, I ended up buying a simple Leviton in-line lamp cord switch which is large enough to hold the resistors inside and can be found online or a hardware store. I unfortunately didn’t take photos at the time, and I admit it wasn’t pretty inside; I had to use some hot glue to keep wires where I wanted them and rip out the regular lamp cord contacts. But still, it was not too difficult of a project.¬† As this uses a SPST switch, the operation is as follows:

 

    1. Plug USB cable of adapter into Tronsmart
    2. Cycle the adapter switch to off (if it’s not off already)
    3. Switch adapter on
    4. Voila! After a moment, 12V will be coming out on the barrel connector

Note that this switch does not control power entirely; when the switch is in the off position and before cycling it, it will still be outputting 5V. This is likely not an issue for a 12V device, but of course, proceed at your own risk!

While I know my adapter could be prettier, I’ve been happy with it so far. I have 2.1mm y-splitter cable which allows me to charge two devices at a time, usually my D74 (with a small connector adapter) and HD-1 or D74 and 817ND. While it could actually run one of those devices at a time based on its current capability, the inexpensive switching regulator in the Tronsmart is expectedly noisy, so this really should only be used as a charger. Since the Tronsmart is a dual USB port charger, I can bring this adapter to charge my radios and iPhone or iPad all from the same outlet at the same time.

 

Ham Radio on My Trip to Peru

Back in September, I took a trip to Peru with some college buddies. Although none of these friends are hams, it seemed obvious to me that this trip had to include some ham radio, so I decided to bring along my satellite gear.

A late-night attempt to work AO-92 from the pool deck of the Hilton Lima Miraflores.

I started with visiting the ARRL website that provides details on getting a reciprocal license in Peru. Their instructions were to write to Radio Club Peruano (RCP), the national Peruvian amateur radio organization, with a bunch of information at least 40 days before arriving in Peru. I actually first sent a message using the contact form on the Radio Club Peruano website about three months before my trip, but never received a reply. I then decided to send a physical mailing with all the requested information to Radio Club Peruano about 60 days before my trip. A couple weeks later, I followed up with an email copied to every RCP official’s email address I could find. I never received a response to any of these messages which was very disappointing.

Finally, I realized after some more digging that as a US ham I did not need a formal reciprocal license but instead could apply for an International Amateur Radio Permit (IARP) through the ARRL. By this point, I was less than a month from departure day, so I was pleased when I got a prompt response from Amanda at the League who was able to quickly process and turn around my IARP. Within about a week or so, I got my permit in the mail. Awesome!

The next hurdle was the customs regulations. Peru actually has fairly strict rules for what items you can bring in without paying a duty. They specifically call out that only one broadcast radio can be brought in, and although it does not mention ham radios in particular, I did not feel it was worthwhile to argue with a customs agent. This prevented me from using the Ailunce HD-1/Kenwood TH-D74 combination I typically like to use for FM satellites. I decided to bring along my Shorty Arrow and an Alinco DJ-G7 HT which is a full-duplex radio. I also brought some cabling so I could use my iPhone as an audio recorder. The G7 is known to be only a mediocre radio for VHF/UHF full-duplex, but I was hoping it would be good enough for this trip.

Interestingly, in hindsight, I could have easily gotten away with my preferred setup due to the customs process at Lima’s airport. After collecting your luggage, you could either walk towards the green sign which means you had nothing to declare or the red sign which meant you were declaring something and had to go up to a desk. However, the green sign simply led you outside with no check by anyone; I suppose you could be randomly searched, but the crowd was so big that this would practically have not been an issue. Still, I do not recommend you try to lie in this process since the fines can be pretty big.

Although I planned to operate in Puno, Cusco, and Lima, time and altitude sickness prevented me from doing so except in Lima. We were staying at the Hilton Lima Miraflores (which is a fantastic hotel, by the way) which had a rooftop pool that was closed for renovation. This seemed promising at first though since they left the doors unlocked and it was totally empty up there. I attempted a decent AO-92 pass out over the ocean, but it was a total bust. The noise floor was so high that I couldn’t hear a thing despite having perfect line of sight for much of the pass. Oh well, I tried.

In the end, it was frustrating to not get a single grid in the log from this once-in-a-lifetime trip. However, it was still a lot of fun and very memorable overall. I got to go out on Lake Titicaca, see Machu Picchu, and explore Lima with a few college friends. Oh, and I also nearly got stuck in Lima due to American Airlines canceling my flight and almost leaving me stranded for three more days. Exciting to say the least!

 

Collegiate Amateur Radio Initiative Monthly Webinar

Over the past few years, my brother and I have been volunteering with the ARRL to help lead the Collegiate Amateur Radio Initiative. Our efforts have mostly revolved around hosting a booth at Hamvention and leading forums at Hamvention and HamCation. Additionally, we introduced and organized the Collegiate QSO Party and have been helping to manage the CARI Facebook group.

Based on discussion with various college clubs, we’ve decided to try a new monthly webinar allowing a different college/university club can present a club event, project, or other activity. We also are encouraging the participants to ask questions and engage in discussion; our goal is to help clubs work together to strengthen collegiate amateur radio.

We held our first call on January 14, and Case Amateur Radio Club presented some of their 2019 activities including a tie-in with the civil engineering department’s surveying class. We’re planning to upload recordings of the webinar to share afterwards – a link to that should be coming soon in the Facebook group.

Although this is directed at college/university amateur radio club officers, we are leaving it open for other interested parties to attend as well. To attend future webinars, please register.

For those who don’t know, my brother and I were both active leaders in collegiate amateur radio while in school. I was Vice President and President of the Rose Tech Radio Club (W9NAA) at Rose-Hulman Institute of Technology and the President of the Ohio University Amateur Radio Club (W8PZS). My brother was President of the Gator Amateur Radio Club (W4DFU). Some of my fondest college memories were events and activities run by the club including annual trips to Hamvention, late night contesting, and antenna experiments.

I encourage hams to check in with the club at the college they attended and see how they can give back; whether it be money, equipment, guidance, or just an extra hand putting up a new dipole, clubs are always in need of help. With administrative challenges becoming more significant for most college clubs, the support and nudging of alumni can be powerful in helping a club get things done. I was lucky to make some great alumni connections through the radio club as well, and those people have been great mentors to me in amateur radio and my career.