Author Archives: Tony

March 2021 Satellite Operations Gear

At the time of posting, I’m actually in the midst of changing my satellite gear so it is no longer my current setup. That said, I wanted to document it before I forgot about it and pass along my thoughts in case anyone else finds the information useful in the future.

In general, the radios and antennas for my ham radio satellite operations I’ve used have not changed since my last gear update (February 2020 Satellite Operations Gear). Check out that post for more details, but basically I use a Kenwood TH-D74 for a receive radio, an Yaesu FT-817ND as a transmit radio, an Arrow Antenna (now a custom-drilled version by WY7AA), with a variety of cables and adapters in between. In the last six months, I added a 3 Ah Bioenno battery pack to power the FT-817ND as well as a David Clark PC headset to replace the cheap PC headset I previously used.

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Powering a Ham Radio with USB Power Delivery

A while back, I built a cable to power 12V devices (in my case a Kenwood TH-D74 HT) using the QuickCharge standard available in some USB power adapters. This allowed me to use a USB charger to charge my HT rather than bringing a dedicated wall wart which helped save some space when I traveled. While my homemade cable was electrically simple and worked as expected, it was a bit clunky. Also, QuickCharge is largely being replaced by USB Power Delivery (USB-PD), and since my laptop chargers using USB-PD, I found that I could consolidate my charging needs further by getting an adapter that works with USB-PD. 

Of course, I’m not the first person to try to adapt USB-PD for other purposes, so I was able to find a few products that partially solved this problem. I quickly came across a line of small adapter boards that negotiate the USB-PD protocol and provide an adjustable or preset voltage based on the standard. These are available on Amazon (affiliate links on this page) but can also be found even cheaper on eBay if you’re willing to wait for shipping from China.

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Replacing Top Panel and Belt Clip on Kenwood TH-D74

I’ve enjoyed using the Kenwood TH-D74 for the last four years or so, and despite its regular use and fragile design, it has survived that period without any major damage. However, a couple years ago, a small crack started to develop on the back of the case next to the belt clip. I don’t recall dropping the radio ever, so I assume this must be from bumping into other stuff when traveling with the radio in my backpack. I filled the crack with some glue to try to stop it from growing and that seemed to mostly work, although I was still concerned about water ingress. I’ve tried to be careful since and haven’t had any issues.

Fast forward to a few weeks ago, and I’m out hiking with the D74 to test APRS with a new antenna. As I go to clip the radio on my pocket, the belt clip snaps in half. I didn’t use the belt clip too often, but the plastic must have just weakened over time. I noticed that the spring is quite tight so that even when snapped in half, there is enough pressure on the clip to close it all the way to the radio body as you can see in the first photo above. Perhaps a poor design, but in any case, I needed to fix this one.

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November 21-22 Roving Plans (EM48/49, EM58/59, EM69, EN70/71)

After a hiatus from the sats for a few months, I’m planning to hit some new grids during the weekends around Thanksgiving. These are tentative plans and subject to change. Follow me on Twitter (@kd8rtt) for real-time updates during the rove and frequencies for the linear sats before the pass. I might also hit some or all of EN60, EN61, and EM49 the following weekend, so check back later during the week of Thanksgiving for details.

Saturday, November 21:

EM48/49 Grid Line 
16:07Z XW-2A
16:30Z AO-91

EM58/59 Grid Line 
20:32Z CAS-4B or 20:35Z CAS-4A (TBD)
20:51Z PO-101 or 20:53Z SO-50 (TBD)

EM69
01:32Z CAS-4B or 01:35Z CAS-4A (TBD)
02:35Z XW-2A
Other passes possible for skeds during the evening. 

Sunday, November 22:

EN70/71 Grid Line
18:11Z RS-44

Keeping Arrow Antenna Elements Tight with Loctite

I’m a big fan of the Arrow Antenna for satellite operations for its good performance and portability, but one issue that pops up is the constant need to tighten the elements. I leave my Arrow assembled in the back seat of my Honda Accord, so it loosens up on its own. This is annoying from a clanging noise perspective, but it also messes with the performance of the antenna and throws off the SWR.

In a discussion some time ago on Twitter, Mike, W8LID, suggested trying fully aluminum threaded rod as he noticed this eliminated the problem and lessens the weight of the antenna slightly. Apparently, the included threaded studs are zinc plated steel which doesn’t tighten nicely against the aluminum threaded inserts in the arrow shafts. McMaster-Carr sells this threaded rod (8-32), but I found it locally at a metal shop so I saved on shipping costs. You can use a hack saw to cut 2 1/4″ pieces and you’re good to go with some minor filing to clean up the ends.

The aluminum studs developed small bends which become big deflections at the end of the 2m elements!

For the past year or so, I used this setup and it did solve the loosening problem nicely, but I recently noticed the elements were looking bent and misaligned. It also was sometimes difficult to dissemble the antenna as the aluminum hardware was binding a bit too tight to get a good grip to loosen it. I’ve been thinking about switching back to the original studs for these reasons, but I was still concerned about the constantly loosening elements.

A couple weeks ago, Sean, KX9X, held a RoverCon on Zoom, which aimed to provide a forum for satellite operators to meet, talk roving, and have a good time. During this, R.J., WY7AA, who is well known for making awesome drilled out masts, mentioned a solution the to loosening elements problem: purple Loctite. Purple Loctite, or officially Loctite 222, is a low strength threadlocker, weaker than the more common blue Loctite. He suggested putting a dab of it on one side of the threads to lock in the stud into one side of the arrow shaft. This leaves the other side free to easily dissemble, but prevents them from loosening on their own. I ended up using off-brand threadlocker on my own (Permatex 24024). I’ll update this if I have any issues in the future, but I look forward to have a nice and snug Arrow Antenna again without the fragility of aluminum studs!

Activation Report: Prairie Dog SP (POTA K-2349) and DN90/EN00 Grid Line

Day  three of my  4th  of  July  rove – and the 4th of July itself – led me  to  Prairie  Dog  State  Park,  an interesting  park  that’s  named  after  the  creatures  that  inhabit  the  area. After arriving, I headed to the Prairie Dog Town, a field in the park that has tons of prairie dog holes spread all around starting only a few feet from the parking lot. This was the first time I’d every seen a prairie dog, and I was surprised to hear the chirping sound they make. Unfortunately I only had my iPhone camera and couldn’t get too close before they ran into their holes to hide, so the photos I grabbed weren’t too great. There was a nice pavilion overlooking Prairie Dog Town, which ended up being my operating location for my POTA activation. I had some time to kill before the first satellite pass, though, so I headed over to the nearby nature trail to walk around for a half hour or so and enjoy the beautiful day.

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Activation Report: Webster SP (POTA K-2354) and DM99

After spending the night in Concordia, Kansas (see my 7/2 activations for more information on the preceding stops), I headed toward Webster State Park on the morning of July 3rd to grab some of the FM passes. After arriving and driving around a bit, I found the park fairly full (which makes sense given it was 4th of July weekend), so there weren’t any areas with a shelter available for me to use for a few hours. I decided to park at the Archery Range which was empty and on a hillside. This is not the first POTA activation I’ve done from a state park archery range, and I often find these as decent options since they are rarely in use when I’m at the park. This one had a couple picnic tables but no shade, so I mostly hung around my car.

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Activation Report: Glen Elder SP (POTA K-2339)

As the second stop on my 4th of July weekend rove after Lovewell State Park, Glen Elder State Park provided another nice place to give out the EM09 grid to many of my fellow satellite operators who needed it. I arrived in the middle of the day and quickly searched for a good operating position. As the AO-91 and AO-92 passes (the easy FM ones) coincided with my Lovewell activation, I knew this park could be a bit of a challenge to activate in a short amount of time. After leaving this park, I knew I had about another hour drive to my hotel in Concordia, KS which added to my desire to make this quick. I had already driven over four hours from the Kansas City area that morning, so I was tired to say the least.

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Activation Report: Lovewell SP (POTA K-2343)

This year for the 4th of July holiday weekend, I decided to do a four day rove to hit four new POTA parks (K-2343, K-2339, K-2354, K-2349) and four new grids (EM09, DM99, DN90, EN00) around northern Kansas. I’ll be posting a separate writeup for each park, so check out my overview page for links to the other activations. On Thursday the 2nd, I left my home in the Kansas City suburbs early in the morning for the approximately four hour drive. I decided to head north to St. Joseph and then travel US 36 almost the rest of the way which was a much nicer drive than the alternate I-70 option. I got to travel through a bunch of small towns and see a real beautiful part of rural Kansas. The drive up was mostly uneventful, although as I neared Lovewell, Google Maps routed me down a gravel road that soon turned to dirt. As I rounded a hill, the back end of my car started to slide around me, and although I didn’t spin out, I ended up in the mud and stuck. Using some of my snow driving skill learned during my Ohio upbringing, I switched off traction control, and my front wheel drive Honda Accord was able to make it on its way. I nearly got stuck two more times on that road before before hitting pavement again. A little rattled and worried if I’d miss my first planned pass at the park, I raced down the country roads in my now mud-caked sedan.

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