All posts by Dave

POTA Activation – Martial Cottle Park State Recreation Area

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Date: July 23-25, 2022
Park : K-3473 Martial Cottle Park State Recreation Area

Unfortunately, it took another year before I was able to attempt another POTA activation! I had certainly been hunting in the meantime, but I still wanted to work towards more activations. Unfortunately, there aren’t a ton of state parks nearby, and only 2 within the county. One that is in the county, is luckily very close to the QTH.

By most standards, I’d consider Martial Cottle Park to be a relatively young park. There are a fair amount deed restrictions from when the land was given to the state, and they haven’t fully realized all the plans for the park. As such, the park is quite nice, but there isn’t much shade around the park benches (besides the reserved areas). They’ve planted trees, which will provide shade someday… just not yet.

I decided to be a bit creative and find what shade I COULD find, which was in the parking area. There was a fence that I used to help hold the counterpoise up, which made it convenient. Unfortunately, this did mean that the antenna ended up being in the trees a bit. I decided it was a necessary compromise.

Setup station in the back of the Jeep Cherokee, running FT8 on the laptop, and the antenna behind me.

My Gear for this adventure :
Radio : Xiegu G90
Audio Interface: DigiRig Mobile
Antenna : Buddistick Pro

I had plenty of shade, and there was a nice breeze, making it a pretty comfortable location. The chair and station setup wasn’t all that comfortable, but certainly serviceable.

July 23rd (UTC) – Showed up in the afternoon, and scouted the park to setup. It took a little bit to figure out how I wanted to set things up, but was able to get the activation with relative ease. It did take a couple hours, as I had to remember the best way to setup the Buddistick Pro. I spent most of my time on 20m, with a short attempt at 40m. I was struggling to get 40m to tune right, and just stuck to 20m. I hadn’t budgeted my laptop battery well, and had to stop earlier than expected.

July 24th (UTC) – Arrived in the early afternoon again, and was able to activate again on 20m FT8. I planned my battery usage better AND decided to try to do a Late Shift Activation as well. Once I had activated, I closed up the laptop to save battery for the Late Shift. While I was killing some time, I tried to figure out my 40m issue. I realized I had assembled the Buddistick Pro incorrectly, which I blame on it being a year since I last used it!?

July 25th (UTC) Time for the Late shift! Unfortunately, there was just a lot of QRM on 20m and 40m. Even after budgeting my battery, the 6Amh Bioenno battery for the radio ended up not lasting to get the activation. I decided to turn on the car and charge the battery for a bit. Sadly, it was quickly approaching park closing and QRM was just getting worse. The Late Shift Activation was busted, but I decided to come back the next morning to finish the activation.

Overall, it was fun to get out and do some activating again. It was clearly needed, since I had not remembered the proper way to setup the antenna. I’m not sure when I’ll get back there, but I expect to have many more activations in due time.

Buddistick Pro, making use of the fence for the counterpoise.

POTA Activation – Muskegon State Park

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Date: July 26 2021
Park : K-1525 Muskegon State Park

After my first POTA activation, I decided to give another park a try! I had to decide between activating the same park again, or going to a new park. I saw that there was another park nearby, called Muskegon State Park and it was only 10 minutes further away.

Since I wasn’t aware of how this park was arranged, I had to do a little exploring, and discovered it was really a hidden gem. There is tons of parking, beach space, and felt pretty quiet everywhere I explored. I did notice that there was an old lookout fort that was up on a hill. I decided to use a small parking lot near there, as there was shade, picnic benches, and no one else in the parking area.

Buddistick Pro antenna with the lookout fort in the far background.
Buddistick Pro antenna with the lookout fort in the far background.

My Gear for this adventure :
Radio : Xiegu G90
Audio Interface: DigiRig Mobile
Antenna : Buddistick Pro

Station setup on the picnic table.
Station setup on the picnic table.

I had planned to activate the park with FT8 again, but it was apparently not meant to be! As I was setting up the station, I discovered that the CAT side of the DigiRig audio-interface had somehow broken since I last used it! (DigiRig was awesome and replaced it with great ease) I wasn’t emotionally prepared for that. I tried to setup VOX on the G90, to handle the PTT side of things, but just couldn’t get it going in the field. I wasted a fair bit of time on that, but eventually gave up.

I came to the realization I needed to give-up or switch to SSB. Having not done much SSB on HF, this was more daunting than it would be today. I was able to launch HAMRS, spot myself on the POTA site, and start making contacts. In the end, I made 13 QSOs before packing up to head home. There was a lot of noise on the bands that day, and I ended up having to move around a lot. Thankfully, the hunters followed me and I was able to make it successful!

First POTA activation – Duck Lake State Park

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Date : July 22 2021
Park : K-1496 – Duck Lake State Park

After trying my first Summit on the Air (SOTA) activation, I was excited try try doing a Parks on the Air (POTA) activation as well! I was going to be traveling to Michigan and have some free time. Taking a look at the POTA website, it was clear that Duck Lake State Park was going to be the closest park to visit.

Driving into the park, I didn’t have a great sense of where would be good to activate. I knew that the beach area would be VERY busy, and would not have much shade. When you first arrive, there is a large parking lot, but it seemed pretty busy around there as well.

The first decent option looked to be an empty park bench at the boat launch parking. There was low traffic, open space, and an available bench. The biggest problem with this spot was the lack of shade.

View of Duck Lake from the operating station.
View of Duck Lake from the operating station.

I kept going down the road and found that there was a pavilion that could be rented out. Unfortunately, the pavilion was in use, but there was a path that went down toward the lake. there were open benches, lots of space, and little foot traffic. So, setup on a bench in the shade and got started.

My Gear for this adventure :
Radio : Xiegu G90
Audio Interface: DigiRig Mobile
Antenna : Buddistick Pro

Station Setup on the Picnic Table
Station Setup on the Picnic Table
Buddistick Pro
Buddistick Pro

I decided to make this activation with mostly FT8. I had 10 FT8 contacts, followed by 2 P2P SSB contacts. This was hardly an amazing number of contacts, but was more than sufficient to fully “activate” the park! It was largely an experiment for me and a learning experiment.

This was also my first time using the Buddistick Pro. The antenna only barely arrived in time for my trip, so I hadn’t had any time to test it out before flying to Michigan. It performed really well, and was perfect for my situation. I had heard from multiple people that Michigan doesn’t allow you to hang anything from trees, so my normal KM4ACK EFHW wasn’t going to be an option. I needed something self-supporting and this seemed to be a great option. So far, I’m quite happy with the antenna and would easily recommend it.

First VHF Contest and SOTA Activation

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In May of 2021, I had started to get reinterested in ham radio. While playing with APRS, I learned about SOTA and realized there was one parcitcally in my backyard! Around the same time, I learned that there was an upcoming VHF contest. Since I didn’t have an HF radio, this seemed like the great combo!

VHF Contest : ARRL June VHF Contest
SOTA Reference : W6/NC-399 (Coyote Peak)
Date: June 13th, 2021

The summit is only a little over 1000ft, making it a seemingly easy hike, or so I thought. I had done some planning, and looking at Google Maps, it estimated it to be 2 miles and ~1hr hike.

Coyote Peak Trail
Trail marker for the Coyote Peak Trail, on the hike up the hill!

Unfortunately, I misread one of the trail markers (not the one shown) and ended up taking a longer route, which was ~3.5 miles and took me 2 hours. It was a pretty hot day and the trail was significantly more steep than I had anticipated. Talking to others that have that have done this hike, it would have been an even more steep hike on the planned trail.

Eventually, I did make it to the top of the trail. Thankfully the tower at the summit is an easy target to track and keep focused on.

Approaching the tower at the summit

Even though I can walk to the trail from my house, I might consider driving to the visitor center, and then hike up from there for my future activations. Based on the other people hiking to the summit, it seemed like a much easier method!

I had never done a VHF contest or SOTA, so I wasn’t really sure what to expect or how to properly prepare. Like most people doing something for the first time, I ended up overthinking and over preparing! My instinct was that my HT antenna wasn’t going to be sufficient to really make any distance. I then recalled that I had a spare mag-mount dual-band antenna that could be used. I also recalled legends of people using a cookie sheet with a mag-mount antenna, when trying to operate from apartments or HOA environments. I went over to my local Dollar Tree store and purchased a pizza cooking sheet. Somehow the round aspect of it seemed a little more appealing than a rectangle!?

Dual-Band Mag-Mount Antenna on the Dollar Store Pizza Cooking Sheet

Although it was a hot and difficult hike to the top, it was amazingly pleasant at the summit. There was a steady breeze, which made audio a little complicated, but made it a great place to sit for an hour.

Overall, I activated the SOTA and participated in a contest. This was a great experience to work on “mic fright”! I’m glad I did it and hope to make it to the top of the summit again. It is so close, I have not excuse for not doing it. I just hope it is a bit easier the next time.

View from the summit of Coyote Peak

Fake CM108 USB Audio Devices

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While working on some projects for APRS, I had the need for some more USB audio devices. LONG ago, I had purchased some “3D Sound” USB devices on eBay. These old devices used a chipset (Tenx TP6911) designed for “headsets” and have a fairly poor ADC, with a max of 24 KHz resolution (pretty low). The C-Media 108 chipset has long been considered a decent value chipset, so I went to eBay to find some CM108 based USB devices. I found a listing that was explicitly stating that it had this chipset.

eBay listing for CM108 USB Audio chipset devices
Clearly claims to be CM108 Chipset… but what is it really!?

I had heard about fake chips being out there, and knew that it was a strong chance of this being the case. But hey, these are plenty cheap and it was a low risk experiment!

I plugged one into my Raspberry Pi and ran dmesg

[  136.786975] usb 1-1.3: new full-speed USB device number 3 using xhci_hcd
[  136.933737] usb 1-1.3: New USB device found, idVendor=08bb, idProduct=2902, bcdDevice= 1.00
[  136.933757] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[  136.933774] usb 1-1.3: Product: USB PnP Sound Device
[  136.933789] usb 1-1.3: Manufacturer: C-Media Electronics Inc.
[  136.956376] input: C-Media Electronics Inc.       USB PnP Sound Device as /devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1-1.3/1-1.3:1.3/0003:08BB:2902.0001/input/input0
[  137.017913] hid-generic 0003:08BB:2902.0001: input,hidraw0: USB HID v1.00 Device [C-Media Electronics Inc.       USB PnP Sound Device] on usb-0000:01:00.0-1.3/input3
[  137.110053] usbcore: registered new interface driver snd-usb-audio

So far, it seems to be OK. dmesg is clearly saying this is a C-Media device that has been detected. Next I ran lsusb:

pi@raspberrypi:~ $ lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 08bb:2902 Texas Instruments PCM2902 Audio Codec
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
pi@raspberrypi:~ $

Hmmm, that doesn’t look like C-Media! It clearly shows that it is a TI PCM2902 chipset! Well, let’s try another command, which is likely looking at similar datapoint:

pi@raspberrypi:~ $ inxi --audio
Audio:     Device-1: bcm2835-audio driver: bcm2835_audio
           Device-2: bcm2711-hdmi0 driver: N/A
           Device-3: bcm2711-hdmi1 driver: N/A
           Device-4: Texas Instruments PCM2902 Audio Codec type: USB driver: hid-generic,snd-usb-audio,usbhid
           Sound Server: ALSA v: k5.4.83-v7l+
pi@raspberrypi:~ $

If you look at the PID and VID from the dmesg and lsusb outputs, it shows “08bb:2902”. Doing some independent Google searches and you’ll see that it is indeed referencing the PCM2902 chipset.

So, we seem to have devices that are PCM2902 and NOT the CM108. Presumably, the eBay seller altered the firmware to display the C-Media in the labeling. If someone plugs these into a Windows machine, they would just see the C-Media labeling and be unaware of what is actually being used. Because most USB audio devices use a universal standard, there isn’t a driver confusion that would have made it obvious.

How do these chipsets compare?

C-Media CM108Texas Instruments PCM2902Tenx TP6911
DAC Sampling Rate48 / 44.1KHz48 / 44.1 / 32KHz48 KHz
ADC Sampling Rate48 / 44.1KHz48 / 44.1 / 32 / 22.05 / 16 / 11.025 / 8 KHz24 KHz
DAC SNR93 dB96 dB?
DAC Dynamic Range92 dB93 dB?
ADC SNR90 dB89 dB?
ADC Dynamic Range88.5 dB89 dB?
Resolution16 bit16 bit?
CM108 vs PCM2902 vs TP6911

Based on these specs, the PCM2902 isn’t a whole lot different than the CM108. There are certainly other things to consider when comparing. I included the TP6911, as that was what I was initially trying to replace and improve. Clearly either of the PCM2902 and CM108 are going to be better. I couldn’t even find more details or specs on the TP6911, even on the official datasheet!

For now, I plan to just use these PCM2902 and see how they perform. They may not be what I expected to receive, but they should get the job done.

APRSHOG Alert and Notification

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During my lunch today, I was doing some testing with setting-up a receive-only APRS iGate. While I was watching the logs and troubleshooting a problem, I saw my callsign whiz by the screen. Oops! I had received a phone-call as I was getting out of the car, and forgotten to turn-off my HT! I quick went over to the NorCal APRSHOG site to see how “bad” I had been. Sure enough, I was already listed at #25 in the ranks at the time. I quickly ran-out to the car and powered off the HT.

This was all unintentional, and I am very conscious of the APRS traffic congestion, which is why I was working on setting-up a receive-ONLY APRS iGate. I decided I needed to find a way to try to monitor and make sure that I am alerted if this happens again. Next time this happens, I may not be watching APRS logs.

I wrote a little script that I called “aprshog-alert” to run on my Linux server. The script takes in my CALLSIGN and the threshold I want to be alerted on.

It will email me if my APRS callsign is ranked between 1 and 25 (considered a hog!):

[root@host ~]# ./aprshog-alert KI6ETL-9 25

Script:

#!/bin/sh
CALLSIGN=$1
LIMIT=$2
EMAIL="callsign@example.com"
SITE='http://www.norcalaprs.net/usagex.html'

RANK=`wget -q $SITE -O – | grep $CALLSIGN –before-context 1 | head -1 | sed -e :a -e 's/<[^>]*>//g;/

if [[ -z “$RANK” ]]; then
true;
elif [[ “$RANK” -le “$LIMIT” ]]; then
echo You are on the APRSHOG list at a rank of $RANK . Check on $SITE | mail -s '# APRS HOG ALERT #' $EMAIL
fi

I am confident that there are more elegant methods to accomplish this, but I wanted something usable immediately.

The final step is to add this as a cronjob on my Linux system, to run on an hourly basis. I don't want to abuse the APRSHOG site, so more frequent would be inappropriate.

73’s HAMigg, We’ll See You Another Day

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This is old news now, but I felt compelled to post, since it has been a year since I have posted.

On June 18th, 2007, I posted about a new and exciting ham site called HAMigg.de. As of February 25th, 2008, HAMigg.de no longer exists. DL6KAC explains why the site was taken down, on his blog.

I personally am sad that the site closed, but understand his reasons. Really, I just think the ham community wasn’t quite ready for it. I had supported Christian by purchasing hamigg.com and having it forward to his site. I’ll hold onto the domains with the hope that someone can pick up the torch again and see if it will be more accepted.

CQ-CQ-CQ this is KI6ETL/AG

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Last night I successfully passed the Element 3 exam for the General License. It has been just under a year since I got my Technician License. In this short period of time, I have learned a lot and met a lot of great people. I prepared for the exam by taking the FARS General License Class and we met one night a week, for 6 weeks. I'm sure we would have spread the class out longer, but there was a desire to get the tests taken before the July 1st question pool change. I'm not sure of the actual statistics, but it seemed like most people passed the exam. Now I need to decide what kind of HF rig I want/need.

Ham Radio + digg.com = HAMigg

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It appears as if DL6KAC of ham-blog.de has come up with an interesting idea. He has created HAMigg, which is a social bookmarking site like digg.com but dedicated to ham radio! I think this could be very successful, as long as people get the word out. The name of the site doesn't exactly roll off the tongue, but gets the purpose across to those familiar with its inspiration. I'll be watching the site, and likely submitting to it as well.

Kenwood – Busy with RoHS

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After writing “Kenwood Amateur Radio Division in Trouble?”, I decided to make a call.

I just spoke with Phil at Kenwood USA. I had called him, because I’ve been curious if a new 1.2Ghz HT would be coming out anytime soon. Unfortunately he said that their current task list is as such:

– Revampin current product lines to be RoHS compliant. One driving force to be RoHS compliant, is to be able to sell some of the equipment in Europe.
– Finish work on a new HF rig and release it (~1yr out).
– Start working on other new equipement.

Overall he said that I shouldn’t expect a 1.2Ghz radio for another 3 years. Phil’s suggestion was to use SkyCommand (or similar) from my HT, to connect to a TS-2000 at home (if line-of-sight was available).

An interesting side-note was that originally the Kenwood TH-F6A was going to be a quad-band with 1.2Ghz. Apparently the engineers were not able to get the radio to be quad-band with anything more than .5 watts on 1.2Ghz. The team decided to remove the quad and leave it as a tri-band, which ended up being one of their best selling HT’s ever.

I am confident that RoHS is important, and a good thing for Kenwood. Unfortunately this may cause them to slip behind the competition in the process. At the same time, it may provide them the excuse to skip a “generation” of technology.