Category Archives: WSPRSONDE

BeaconBlaster, Uncategorized, WSPRSONDE

Six Band Filter-Combiner

This has been in use for a while, combining the multiple outputs of the Beacon Blaster and WSPRSONDE onto one SMA jack, allowing the use of a single antenna. The results have been excellent, so this box is now on the Turn Island Systems website, available for purchase:

Six Band Filter-Combiner

A product manual is available, as well as a general discussion of the filter-combiner concept.

Applications for the Filter-Combiner are not limited to the WSPRSONDE. Some have used this to combine the outputs of other QRP (1W or less) transmitters. One person is using the Filter-Combiner in reverse as a general preselector, sending the output of a single multiband antenna to several narrow-band SDR receivers (reducing overload from out-of-band signals).

What about eight bands? I glad you asked that question! Fitting additional bands into the combiner has proven to be a major challenge. A 160 meter port can’t be implemented using available (inexpensive) components — too much inductor loss. Squeezing the 17 and 12 meter bands into the gaps between 20, 15, and 10 meters also requires inductor tolerance and loss well beyond that of readily-available parts. However, if there is demand for it a future combiner could include a 6-meter port.

But single-channel filters can be provided for those “oddball” frequencies.

BeaconBlaster, FST4W, WSPR, WSPRSONDE

WSPRSONDE-8

Announcing the next stage in Beacon Blaster evolution: The WSPRSONDE 8!

This is still in development, but the initial prototypes look very promising. Similar in many ways to the BB-6, this has the same type of frequency-flexible 1W Digital (square wave) outputs, the same GPS and 10 MHz clock reference inputs, 9-24VDC input, and USB configuration port. The WSPRSONDE-8 supports both WSPR and FST4W-120 modes.

But the WSPRSONDE-8 adds these new features:

  • Eight frequency-flexible outputs, 1W, 160-6 meters (requires external filtering)
  • Spurious output levels greatly reduced. The BB-6 was designed to meet a spurious output level of -40dBc or better. The WSPRSONDE-8 uses a different modulation technique to provide close-in spurs typically better than -90dBc
  • A single-board design that eliminates the many subassemblies and interconnections inside the BB-6. This is a rugged system.

The WSPRSOND-8 provides ultimate frequency accuracy and stability limited only by the external 10 MHz reference.

WSPRSONDE-8 shown with 6-band filter/combiner and Bodnar GPSDO
Close-in spurious typically better than -90dBc (20-meters shown here, spurs -96dBc)
Using the 6-band filter/combiner, the harmonic outputs are typically better than -60 dBc (20 meter output shown here)