ZUMSpot and openSPOT 3

I have been casually using DMR, D-STAR and YSF (Yaesu System Fusion) modes for a couple of years, using a ZUMSpot. The ZUMSpot is a small board that sits on a Raspberry Pi Zero W. It incorporates a Multimode Digital Voice Modem (MMDVM) and a 10mW UHF transceiver that operates YSF, DMR, YSF2DMR, D-Star, P25 and NXDN modes. The ZUMSpot uses Pi-Star digital voice software. Pi-Star is a custom, pre-configured SD Card image for the Raspbperry Pi, with configuration and operation performed through a web browser. The Amateur Radio Notes website has an excellent tutorial on setting up and configuring Pi-Star. While the Pi-Star configuration appears daunting at first, it is easy to set up by following the tutorial. There are also several videos on YouTube with instructions for configuring Pi-Star.

A few days ago, I was attempting to update the Pi-Star software and the ZumSpot firmware, but kept seeing errors during the firmware update. After several attempts to update the firmware, the ZumSpot wasn’t operating properly*, so I decided to purchase an openSPOT 3, which is made by SharkRF in Estonia.

The openSPOT3 is a battery powered, portable, standalone digital radio internet gateway (aka hotspot). The openSPOT 3 is also configured through a web interface, but the interface and steps for configuration are different than Pi-Star’s. The openSPOT 3 user manual is a web page that is updated frequently when there are firmware updates or features added to the device. Having learned the basics of DMR, D-STAR, and YSF with the ZUMSpot, I found configuration of the OPENSpot 3 to be fairly easy.

* After I had the openSPOT 3 up and running for a few days, I decided to attempt the ZUMSpot firmware upgrade again. It turns out I had missed a step in my earlier attempts, and this time the update was successful. So now I have two MMDVMs!

Both the ZUMSpot and OpenSPOT 3 are excellent MMDVMs. Both are capable of operating the most popular digital voice modes using a DMR, D-STAR or C4FM radio. Also, they both require a wi-fi connection and are configured through a web interface. The openSPOT 3 is great for portable operations since it has a built-in battery and the configuration web page works very well on a mobile phone web browser. Since the ZUMSpot is based on a Raspberry Pi Zero W, it could also be used portable with a USB power bank. The openSPOT 3 costs a bit more more than the ZUMSpot. There are also many other MMDVMs on the market, including inexpensive generic boards and kits available on Amazon and eBay. Digital voice modes with MMDVMs are a great way to talk to hams from all over the world using a VHF/UHF digital radio and an Internet connection.

The Pi-Star configuration panel is used to enter all of the necessary settings for the MMDVM to operate properly.
The Pi-Star Dashboard displays a call log and the current status of the MMDVM.
The Pi-Star Administration panel displays some additional status information, and options to change some of the settings for the digital mode currently in use.
The openSPOT 3 has a “Quick Setup” page to configure the openSPOT3 with the transceiver and connect to the preferred network.
The openSPOT 3 status page and call log – you can see information about the openSPOT3’s current status, and listen to call audio on this page.
openSPOT 3 in DMR mode with Anytone 878
ZUMSpot in D_STAR mode with Kenwood TH-D74
openSPOT 3 in YSF mode with Yaesu FT3D
Both the ZUMSpot and openSPOT 3 can be configured to send your station location via an APRS server

Hamshack Hotline

A local ham friend shared a link with me for Hamshack Hotline, which is a free dedicated VOIP service for the ham radio community. In order to get on this network, I purchased a used Cisco SPA504G IP phone from eBay for $29. There are several other IP phones that will work with the service, but the SPA504G works great, and the price was right! It is important when purchasing a used phone to ensure that it is unlocked. The Hamshack Hotline website has all the information necessary to get started.

Once I received the phone, and connected it to my home network, I followed the instructions on the web page, and submitted a ticket for a new line using the HHOPS Help Desk. The Help Desk web page also includes a knowledge base and downloadable documents that are a great help for installing an IP phone on their network.

Within a couple of days, I had a response from the Help Desk team with my new HH phone number, and a link to a provisioning document for my phone. The instructions were easy to follow, and the team has created a process for provisioning that is nearly foolproof. I say nearly because I did have a slight issue with my home network, but the Help Desk team came through again and got me up and running very quickly!

My Hamshack Hotline phone number is 11642.

New VUCC and WAS Award Milestones Reached!

Due to work obligations, I haven’t had much time to spend on the radio, or to update this blog. Since my last update, QSOs with several stations have been confirmed in Logbook of the World, allowing me to reach a achieve a couple of new awards.

I recently received a LoTW confirmation for a QSO on 6 meters that took place in July. This confirmation was number 300 on 6 meters, and an endorsement for the 50 MHz VUCC Award.

It took a while, but I finally confirmed 300 grids!
Grids confirmed on 6 meters for N1ADM

Also, on November 28th, I had a FT8 QSO on 12 meters with a station in Alaska, which gave me my 50th state for the Worked All States Award on 12 meters. I still need to work Alaska on 10 meters for a 5 Band WAS, so hopefully the band conditions will continue to improve!

Alaska on 12 meters, finally! Now hoping for 10 meters!
I am getting close to WAS on all HF bands!

Morning DX on 40m and 15m

It has been a while since I’ve found time to add a post, or to spend much time on the radio. On this Saturday morning, I decided to get up a little earlier than usual to check the band conditions for DX. I found some good DX to the west, in the Pacific and Asiatic Russia on 40 meters, as well as to the east in Europe and the Mediterranean on 15 meters. The propagation on both bands was very good, but there were lots of stations so breaking through the QRM made some contacts challenging. I only worked one new country on 15 meters, but it was lots of fun to see the variety of locations active on the bands.

Outdoor Antenna for PiAware ADS-B Receiver

About 3 years ago I built a PiAware ADS-B receiver with a Raspberry Pi 3B+ computer and a FlightAware Pro Stick Plus ADS-B USB Receiver with Built-in Filter. For the antenna, I used an inexpensive 1090-MHz indoor antenna mounted in the windowsill. This is a very easy, inexpensive, and fun radio project with a Raspberry Pi, and I would encourage anyone interested in radio and/or aviation to build one. The FlightAware website includes parts lists and detailed instructions for building an ADS-B receiver with a Raspberry Pi computer. You can also build an ADS-B receiver with a Raspberry Pi computer and hardware from AirNav.

Automatic dependent surveillance–broadcast (ADS–B) is a surveillance technology in which an aircraft determines its position via satellite navigation and periodically broadcasts it, enabling it to be tracked.

This setup worked fairly well, and I was able to receive position and heading information for several aircraft within a range of approximately 50 nautical miles, and sometimes a bit farther depending upon the altitude of the aircraft. An indoor antenna is a compromise solution and will generally limit the range from which ADS-B signals can be received.


This morning I replaced the indoor antenna with a FlightAware 1090 MHz ADS-B Antenna mounted outdoors on a 12-foot fiberglass push-up mast. I used 50 feet of LMR-400 coax cable terminated with N male connectors outside, and a short adapter cable with N male and SMA male for the connection to the FlightAware receiver. The antenna is compact and very light, so the installation was very easy.

After installing and attaching the outdoor antenna, there was a dramatic difference in the number of signals received, as well as the distance. The PiAware will now receive signals for almost every aircraft flying inside of 1oo nautical mile radius, and is receiving some as far away as 200 miles!

New DXCC on 20 Meters – Hong Kong

I haven’t been on the radio much over the past week, but this morning I had some time and found that 20 and 30 meters were open to the Far East. It took a bunch of tries, but I was able to complete a FT8 QSO on 20 meters with VR2XRW in Hong Kong. That’s a new DXCC entity for me, and he confirmed the QSO on Logbook of the World in just a few minutes! The new DXCC entities are becoming fewer and further between, and it’s always special to work a new one!

A few good FT8 and FT4 QSOs on 20 and 30 meters
VR2XRW confirmed our QSO on Logtbook of the World within minutes!
N1ADM’s DXCC Account Status as of August 15th, 2020

Accurate Time for Digital Modes by GPS

Accurate computer time is absolutely essential for successful QSOs using digital modes such as FT8, FT4 and JS8. While millisecond accuracy is not necessary, if the computer clock is off by more than a second, you are likely to experience problems. It is very easy to check the accuracy of your computer’s clock by using the website time.is.

A check of my computer’s clock on time.is showed that it was 0.3 seconds behind. This is well within specs for digital modes.

Recent versions of Windows will frequently update the clock through time servers, but the updates are not usually as frequent or accurate as I would like. There are also several applications that will connect to Internet time servers to periodically update the computer clock. Some examples are Meinburg NTP, BktimeSynch, Dimension 4, and NetTime. I have Dimension 4 loaded on my shack computer.

Dimension 4 periodically updates the computer clock using a low level internet protocol, called SNTP, to connect with special purpose Internet Time Servers.

But what if you don’t have Internet access, due to an outage or working in the field? Fortunately, there are computer applications that will synchronize your clock using GPS signals. To do this, you need the software and a GPS receiver for the computer.

For my computer, I use a GlobalSat BU-353-S4 USB GPS Receiver and NMEATime2 software for GPS-PC time synchronization. The GPS receiver cost me $34, and it also cost me $20 to register the software.

The GPS receiver connects to a USB port on the computer as a serial device. I have the receiver in a windowsill near the computer.

On my computer, the GPS receiver is the Prolific USB-to-Serial Comm Port (COM4).

After the GPS receiver, I installed the NMEATime2 software. It was very easy to set up the software to work with the GPS receiver. Once installed, the software runs in the background to keep the computer clock updated. There is an icon in the system tray that shows the current status.

The green satellite icon in the system tray indicates that NMEATime2 has a good GPS signal lock and the application is disciplining the computer clock.

A right click on the tray icon and selecting “Show Panel” will bring up the software control panel with menus for settings and four tabs: Status, GPS Status, Loop Status, and NMEA Output. For my purposes, the Status panel and GPS Status panel contain the most important information.

The Status panel shows the current time and overall quality of the GPS satellite signals.
The GPS Status panel shows which GPS satellite signals are being received, and the signal quality for each, as well as location information.
The Loop Status tab displays the status of digital filters that filter out any spikes or outliers before sending the filtered signal to the application’s control algorithm.
The NMEA Output tab displays the NMEA data strings as they are received from the satellites.
While running NMEATime2, my computer time is usually exact or very close.

A Nice Surprise from the ARRL DX Contests

I competed in the CW and phone portions of the ARRL DX Contest earlier this year. The CW portion took place February 15-16, 2020, and the phone portion took place March 7-8, 2020. My contest participation is usually casual, and I do not operate for the entire period of the contest. My primary goal during this contest is to work new DX stations.

The ARRL has a page to search contest scores and download copies of certificates earned for contest participation. I usually forget to check, since I never anticipate having a competitive score. When I checked this year, I had a pleasant surprise. In the Single Operator, Low Power category, I placed 3rd in the Georgia Section for both contests!

Recently Received QSL Cards

My preferred method of confirming QSOs is through ARRL’s Logbook of the World. It’s a simple, fast, and easy to use system to confirm contacts and apply for awards. It also saves a ton on postage, since international postage rates are very high. Still, there is something special about receiving a QSL card in the mail after working a rare DX station. In addition to nice keepsakes that have interesting information about the operators and their locations, they are physical proof of the QSOs.

Over the past few months, I have received several new QSL cards. Some are from contacts that took place over a year ago. I have been concentrating on getting confirmations from DX stations in the Middle East, Africa and the Pacific. I really enjoy collecting the cards, and believe they add a personal touch to what are usually very brief DX contacts.

C5FUD, Gambia; 5H3UA, Zanzibar Island; TR8CA, Gabon; V55A, Namibia; S01WS, Western Sahara; Z81D, Republic of South Sudan
JY5IB, Jordan; TU5PCT, Ivory Coast; VP8PJ, South Orkney Islands; E44WE, Palestine; 9J2LA, Zambia; KH0/KC0W, Mariana Islands
KH7XS, Hawaii (on 10 meters!); ZD7JC, St Helena Island; JT5DX, Mongolia; 3D2AG/P, Rotuma Island; 7V5ID, Algeria; FR5DZ, Reunion Island

Another benefit from collecting QSL cards is that sometimes the envelopes have some cool stamps!

Envelopes with cancelled stamps from Finland, Fiji, and St. Helena Island.