Raspberry Pi QRP TX Shield for WSPR on 30 Meters
Nowadays, one of the most impressive QRP modes is Joe Taylor, K1JT's WSPR (pronounced "whisper") mode. WSPR stands for "Weak Signal Propagation Reporter." Programs written for WSPR mode are designed for sending and receiving low-power transmissions to test propagation paths on the MF, HF and recently, UHF bands. The process is similar to a beacon. Users with Internet access can watch results in real time at wsprnet.org.
WSPR Without Tears is Bruce Raymond, ND8I's project to simplify the process of getting an actual transmitter up and running so you can enjoy working with WSPR and avoid dealing with the headaches associated with building a working system. What makes it really interesting is that WSPR is optimized for operating at very low power. Our kit puts out a whopping 200 mW which is capable of reaching impressive distances even with a bad antenna (see the map above for typical response using an-end fed dipole in an attic). The QRPi board (or shield as referred by the community today) is an inexpensive way of turning a Raspberry Pi single-board computer into a QRP transmitter.
Our approach uses a Raspberry Pi computer ($35) to generate WSPR transmissions. Our board plugs into a Raspberry Pi and amplifies and filters the output (the Raspberry Pi output is a very low power square wave that would be illegal to transmit due to its harmonic content). The Raspberry Pi generates the WSPR signal in software and utilizes timing data from the Internet to calibrate its internal clock and transmit frequency, so you don't have to do it.
So join the group of Whispering Raspberries on 30 meters by ordering a TAPR 30M-WSPR-Pi today.
Pablo, WA6RSV, alerted us to the fact that not everyone realizes what a Raspberry Pi is. He said, "One week ago I thought a Raspberry Pi was a dessert! (I like apple pie!). Nobody explained to me that it is a normal computer just like your Mac or PC. You can use it just like a Windows PC to browse the Internet, write an email, etc. The concept is as follows 1) you buy it and you plug in a monitor, USB mouse and USB keyboard. 2) If the MicroSD does not have the operating system (Like Windows or OSX, but for this contraption it's called NOOBS/Raspbian) you go get it at www.raspberrypi.org and copy it into the MicroSD which is also the hard drive/RAM ) After installing the operating system it will work like a NORMAL computer with everything including the built in WIFI (if a Pi 3)."
Note: The "WSPR Without Tears" kit comes with a programmed MicroSD card.
Note: The "WSPR Without Tears" kit also includes an end-fed 30M antenna kit too. See the Antenna Quickstart Guide below.
Note: The "WSPR Without Tesrs" kit does not include the Raspberry Pi.
An assembled version of this kit w/o antenna is also available here.
The price for the 30M-WSPR-Pi is:
$ 34 USD
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Shipping and Handling
Shipping and Handling within the US will be by USPS Priority Mail.
International shipping costs are calculated as closely as possible. If the actual cost exceeds the estimate by more than $10.00, TAPR will contact you to get approval for the additional funds. TAPR uses insured Priority Mail International, unless the purchaser requires something else.
Documentation30M WSPR-Pi Amplifier/Filter Quick Start
30M WSPR-Pi Antenna Quickstart Guide
30M WSPR-Pi Troubleshooting and Appendix
The TAPR 30M-WSPR-Pi project team is:
- Beuce Raymond, ND8I, Project Manager, Designer
- John Koster, W9DDD, logistics