WSJT-X developer Joe Taylor, K1JT, weighed in to express his appreciation to all who shared their ideas and experiences using JT9 and JT65 modes during recent multi-hop E-skip openings on 6 meters.
“We are very much aware that a mode with most of the excellent characteristics of JT65, but with faster turnaround time, would be a big winner in such situations,” Taylor commented on behalf of the WSJT-X development team. “We are experimenting with several such possibilities. Tentative goals include 15-second T/R sequences, sensitivity around S/N = –20 dB, occupied bandwidth less than that of JT65, and capability to decode as many as 10 or 20 signals in a 2-kHz bandwidth.”…
This is something to follow if you are interested in the JT modes for HF and VHF communications. Our experience is that a new JT variant that would trade S/N margin for a faster QSO segment speed would be just the ticket on many of the HF bands as well as 6m.
New member here, hoping to add some value! I am returning to amateur radio after a very long period of inactivity, and have been looking for some reading material to jump-start coming up to speed on more recent technology topics. I have discovered a new book which may be of interest to Nashua ARC members. This is actually a revised 4th edition (published 2017) of a book that has been around for some time. Title: Communications Receivers: Principles and Design. This is an engineering textbook, so it is quite technical but strikes a balance between theory and practice. A bit pricey, but it is a virtual goldmine of information, and includes hundreds of references and suggestions for further reading. At 600+ pages, it is not something most will read and understand in a few evenings. Greatly expanded coverage of SDR technology alone is worth the price, IMHO. I highly recommend this book for those who wish to gain an in-depth understanding of the topics covered. This book might be suitable as the basis for a series of Tech Night sessions.
I wanted to share some information about our tracking our High Altitude Balloon as it flies. Our balloon will carry’s a GPS receiver and a 2m APRS Transmitter.
HAB Flight Platform
The on board APRS transmitter will operate on the Amateur Radio standard terrestrial APRS frequency of 144.390 MHz and will transmit our HAB’s position, heading, speed, altitude and other telemetry data every minute during the HAB’s flight. The transmitter is battery-powered and generates a 250 mW signal into a dipole antenna suspended from the HAB’s flight platform. The HAB will use N1FD-11 as its call sign.
Based upon online HAB flight prediction calculators that we have been using, we expect the HAB’s flight to last a little less than 2 1/2 hours. The HAB should reach an altitude of over 102,000 ft before the balloon bursts and the parachute on the flight platform brings it back to the ground at a safe speed. The above prediction will likely change as we get closer to an actual launch but most predictions have our HAB traveling approximately 100 km between its takeoff point and landing.
HAB APRS Packet Information
Aprs.fi will also store and display a copy of all of the APRS AX.25 packets transmitted by the HAB during its flight. Of particular interest to the STEM element of the flight will be the Balloon’s data on atmospheric temperature and pressure conditions at different altitudes.
All you need to track our HAB during its flight is Internet access and a web browser. Just click on one of the aprs.fi links here to see the HAB’s current location and altitude. If you have an APRS ground station, you may also be able to receive our HAB’s telemetry directly during the flight.
We need cloud cover which is less than 50% and ground wind speeds below 15 mph to launch our HAB. Will will post a final launch date and plans in the Youth Forum on our website. Our next possible launch window is on Saturday, June 3rd. We are all pulling for good weather so that we can launch!
We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.
