Empyrean, Etherkit, OpenBeacon Mini

OpenBeacon Mini Status – Early June 2018

It’s time for a brief update on how things are going with OpenBeacon Mini, the successor to the OpenBeacon MEPT that’s been a long time in the making. For those who are unfamiliar with the new project, allow me to give a very brief overview of its capabilities. The OpenBeacon Mini is an automated transmitter for amateur radio operators that allows for automated transmission of messages using propagation study modes such as WSPR and QRSS, along with many of the other JT modes and CW as well. The carrier is generated by a Si5351A clock generator IC which is fed with a TCXO reference clock for frequency stability. Low-pass filter plug-in band modules allow operation on any single band from 630 meters to 2 meters. The OpenBeacon Mini detects which band module is inserted and sets the frequency accordingly, making band changes as easy was swapping out a plug-in module. The power and a data connection is provided from a USB micro B connection to any PC. Accurate time synchronization is accomplished through this connection, as long as the PC has time set through NTP. The user interface is a 128 x 32 px OLED display and 7 pushbuttons. As always with Etherkit products, all firmware, hardware design files, and and software is open source. Extra pins from the microcontroller and extra clock ports from the Si5351 are broken out for use in experimentation and expansion.

Something like this project has been on the back burner for a long time, and is finally now able to see the light. I intend to launch this as a crowdfunded product at the same time as my Empyrean microcontroller, which is at the heart of the OpenBeacon Mini. The Empyrean is an Arduino Zero derivative in the form factor of small DIP module perfect for breadboarding. I’ll have more about this initiative to post on the blog in the near future.

My first beta tester, LA3PNA, recently received his OpenBeacon Mini and had a chance to put it on a NVIS antenna for a few hours on 60 and 20 meters. As you can see from below, he received plentiful WSPR spots in that short amount of on-the-air testing.

I have another early beta tester working on getting his OpenBeacon Mini on the air soon as well. I am looking at getting one more early beta tester going with this PCB spin, just so that I can be very sure that the next PCB spin will iron out all of the kinks. If you are familiar with MEPTs, using the Arduino environment to compile and load firmware, and don’t mind a little bit of firmware roughness, I’d love to have you on board. Send me an email to milldrum at gmail dot com to let me know you’re interested.

This weekend, I plan to get OpenBeacon Mini going on 6 meters in order to see how it performs there. It should be a perfect time, since it’s also the weekend for the ARRL VHF Contest. Keep an eye on my Twitter account and this blog for further updates on this project.


CRX1 Open Beta

CRX1 Beta
CRX1 Beta

If you don’t follow me on Twitter, you may not have heard that I have been working on a little “warm-up” kit in preparation for the CC1 release. Called the CRX1, this kit is a little VXO-tuned superhet receiver based on my 2010 FDIM Challenge entry, the Clackamas. The CC1 is also a descendant of that project, so you could say that the CC1 and CRX1 are siblings.

The CRX1 is an all-SMT project. The passives are size 0805 and the transistors are SOT-23, so it should be able to be built by most kit builders with the aid of a bit of lighted magnification. All of the components are on a single side of the PCB and things are not very cramped, so it should be a pretty easy build for an experienced kit builder, and within the capability of even a newer kit builder with a few kits under his belt. Here are the key specifications for the receiver:


Frequency Range: Approximately 7.030 to 7.034 MHz (at +13.7 VDC power supply)
IF Bandwidth: Approximately 400 Hz
Current Consumption: 25 mA (at +13.7 VDC power supply)
Power supply: +9 VDC to +14 VDC
MDS: -123 dBm
3rd Order IMD DR: 84 dB
IF Rejection: 74 dB
Image Rejection: 67 dB
PCB dimensions: 70 mm x 100 mm
Antenna Connector: BNC
DC Power Connector: 2.1 mm barrel jack
Phone Jack: 3.5 mm stereo
Key Jack: 3.5 mm stereo
Muting, sidetone (user enabled), T/R switch, external VFO port included

I’m now to the point where I have a small number of beta test kits available, but instead of picking beta testers, I would like to try something different. So this time I’m going to try an “open beta”. The product is simple enough that I don’t think it will need much in the way of help in going from a beta to production. Therefore, I’m going to open sales up to everyone. The documentation is currently in a basic form, although I’m going to expand it quite a bit before it goes into production. Because of the basic documentation, I would like to ask that only confident builders purchase a kit at this point. It will be more suitable for novice builders in the near future when full production commences. You can check out the documentation here if you want to get a feel for what state it is currently in.

The beta kits will sell for $29 plus shipping, although that price will rise a bit at production. You can see the product page and purchase one on the Etherkit store, but hurry, since there are only eight beta kits available!