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BeaconBlaster, FST4W, New Stuff, WSPR, WSPRSONDE

Digital One Watt Power Amplifier

Turn your logic-level outputs into slightly more powerful signals! This design is one I have been using in the WSPRSONDE, and I’ve found it to be so useful that I put it in a little box along with a USB C power connection and a couple of indicator LEDs.

This will require a low-pass filter to convert the square wave output to a spectrally-pure-meets-all-FCC-regulations signal, but that’s pretty simple. This design easily covers all the ham bands between 160 and 6 meters.

TIS-1W Digital 1W Power Amplifier

Equipment using this amplifier circuit has been continuously transmitting for several years, from the steamy jungles of Costa Rica to the frozen wastes of the Arctic and Antarctic, The design and performance is thoroughly described in the product guide.

FST4W, Power, RX-888, SDR, WSPR

Glitchless Power with the TIS-1250

This is another design inspired by and adapted from a KA7OEI project:

https://ka7oei.blogspot.com/2025/01/a-short-term-ups-for-mini-nuc-type-pcs.html

We’ve seen that that the small computers used in wsprsonde (and other) receive installations will reset or hang up during power outages, even when there is a UPS between the utility power and the computer’s power brick. It turns out that many UPS units have a momentary dropout when they transition to backup mode, and the brick power supplies do not have enough internal storage to ride through this transition. This is bad enough in home operation, but especially problematic in a remote installation with limited access.

There are certainly glitchless UPS products available (“on-line” UPS), but these are more expensive and sometimes “glitchless” really isn’t.

The TIS-1250 provides an alternative solution, by using a “supercapacitor” (1.25 Farads) and low-loss charging / discharging circuitry.

See more details here:

TIS-1250 SuperCap UPS
New Stuff, RX-888, SDR

The TIS-B1 Balun is Now Available

The TIS-B1 Balun converts a 50 Ohm signal to a balanced 100 Ohm impedance as needed when using twisted-pair CAT 5 and CAT 6 ethernet cable.

Ethernet cable is being used in advanced balanced wideband “probe” receive antenna systems, where balance and ground isolation is extremely useful in reducing common-mode interference.  The TIS-B1 Balun can be very useful in developing and testing these antenna systems.

For more information, please see the Users Guide: 
TIS-B1.pdf

To purchase:
https://turnislandsystems.com/product/tis-b1-balun/

New Stuff, RX-888, SDR

Mixed-Signal Digital / RF Testing

I have a new post on my ham blog showing a potential Turn Island product, and how I use the TIS-126 Clock Distribution Buffer and the TIS-5351 TinyClock to solve some test-setup problems:

http://wb6cxc.com/?p=501

The new design is a BPSK modulator to be used to generate an in-band time-sync signal. This signal is injected into the antenna port of a receiver and used in time-of-flight and time-of-reception measurements.

The BPSK modulator can also be used to generate over-the-air signals using NRZI BPSK modulation . I show some test results in the blog.

FST4W, New Stuff, RX-888, SDR, WSPR

New Filter and Filter-Preamp – designed for six-meter operation

This is a new filter, designed for use with preamplified “probe” antennas, and many other receive antenna systems. This includes a bypassable low-frequency shelf filter, and can be jumper-configured for either 30 or 60 MHz low-pass anti-alias filtering.

See more details here: https://turnislandsystems.com/product/f3060-filter-shelf-30-60-mhz-lpf/

And a new 60 MHz Filter-Preamp:

This one has an aggressive low-pass filter, optimized to eliminate 88-108 MHz FM broadcast band signals before they can cause trouble. The high dynamic range preamp provides about +20 dB of low-noise gain.

Details here: https://turnislandsystems.com/product/60-mhz-filter-preamp/

BeaconBlaster, FST4W, WSPR, WSPRSONDE

Host a HamSCI WSPRSONDE? — also, Turn Island Systems in QST!

Here is an opportunity to help in the exciting field of ionospheric propagation and other “space weather” research, by hosting a WSPRSONDE system provided by the HamSCI organization. HamSci is looking for a few good sites in North America for these WSPR / FST4W research transmitters. There are already about a dozen of these situated in various locations and HamSCI is looking forward to filling in some of the gaps.

The HamSCI package will include the WSPRSONDE, a 9-Band Filter-Combiner, a Bodnar GPSDO, an 80-10 meter end-fed halfwave antenna, power supplies, and all necessary cabling. You will provide a good home for this gear.

If you are interested, visit the HamSCI website for this project:

https://hamsci.org/wsprsonde-psws-transmitter

Turn Island Systems in QST!

(Well, one of our Filter-Combiners is in a group photo anyway…)

The July 2025 issue of QST contains a great article about reducing the noise from local sources and optimizing WSPR reception, written by Conrad Trautmann (N2YCH) . Conrad is a friend, and a regular contributor to the wsprdaemon community. The TIS Filter-Combiner is shown among a collection of WSPR gear.

BeaconBlaster, FST4W, RX-888, SDR, WSPR, WSPRSONDE

Hamvention Presentation

Here’s a talk I gave at the Hamvention TAPR Forum on Friday. The first half is about SDRs: dynamic range, signal to noise optimization, filtering, sampling and aliasing, etc. Then I share some details about the WSPRSONDE. I enjoyed presenting this to a (surprisingly) full room.

I hope you find it interesting!

[UPDATE: new video above!]

BeaconBlaster, FST4W, RX-888, SDR, WSPR, WSPRSONDE

Going to the Hamvention!

In partnership with TAPR and HamSCI, Turn Island Systems will be going to next week’s Dayton Hamvention. On Friday I will be giving a TAPR Forum presentation covering the topics:

  • Optimizing wide-band SDR receiver performance
  • Development of a multi-channel research transmitter

(At the moment, the Hamvention website forum details are wrong, we are working on getting this fixed.)

Look for the TAPR and HamSCI tables in Building 5 (Hertz). I will be flying the Turn Island Systems banner there, and will be bringing a bunch of Turn Island Systems products for show and tell.

I look forward to seeing you there!

Uncategorized

175% Tariffs

Just a note: Most of my circuit boards are fabbed and assembled in China. My semi-custom aluminum enclosures are also made in China. Recent orders are being charged a 175% import tariff and this will definitely affect the prices I need to charge in order to not lose money.

I am not increasing the prices for currently in-stock items.

BeaconBlaster, FST4W, WSPR, WSPRSONDE

WSPRSONDE Software Update

The WS-8 has new software available, with new features and a flexible method of dynamically changing modes, as well as other options. From the updated User’s Guide:

New Features (software version 2.3.2)

Two new features allow flexible control of the WS-8 operation:

Channel Modes: CHAN

Each output channel can be configured in one of three modes:

  • Beacon – This will be the globally-selected WSPR or FST4W-x modes.
  • CW – The channel will transmit a “Tone-Zero” signal for the duration of the scheduled channel transmit frames.
  • Fixed-frequency – The channel will transmit a continuous “Tone-Zero” signal.

Flexible Scheduling: CRON

This is a loose subset of the Linux “cron”, allowing any WS-8 command to be executed on a minute/hour schedule. This can be used to change any parameter option, including channel transmit schedules, frequencies, and modes.

These powerful options should be used with care, as much of the propagation research benefits from stable and consistent signals.

Both the new program and the user’s guide are available for download:

DOWNLOADS