Friday, 25 October 2019

Learning something new.

During a recent online exchange about WSPR operation, a new user, who I expected was using a WSPRlite TX unit, told me he was actually using a ZachTek unit.

Well, I had never heard of this before, so off I went to the internet, in search of details.
The Zachtek WSPR transmitter.  Image: Zachtek.

At $124, plus 25% EU tax, plus shipping from the US, this is not very cheap, maybe around 150 Euro, total.  The WSPRlite is only about 80 Euro.

But price isn't everything.  The Zachtek is superior to the WSPRlite in many important ways.

First, the Zachtek has on-board GPS, meaning that everything, including TX start time and Maidenhead positioning is derived from satellite data and fixed automatically.  As someone who regularly forgets to bring a mobile phone along into the field to provide that data, I can tell you this is a very important benefit, over and above the WSPRlite.

Also rather more sensible is the Zachtek's output of around 300mW, compared to WSPRlite's maximum of 200mW.  Whilst even very much lower powers are often interesting to test, 300mW will generally give the kind of reliable, DX coverage many are looking for.

The other benefit, so far as I can see, is that the ZachTek already has in-built low pass filters.  The WSPRlite doesn't need filters for the 20m and 30m bands, but for all others, it does.  This is more expense (about 30 Euro), more connections, and a generally more unwieldy and rather fragile thing to deploy in the field.

So, altogether, the Zachtek seems to be a much more capable and convenient alternative to the WSPRlite.  I don't know anything about its reliability in the kind of tough environments one tends to deploy WSPR transmitters.  What I can say is that I've had two WSPRlites fail after about 18 months' use, which seems to be related to moderately cold weather use, even when otherwise protected from the elements.  That isn't great, really.

Zachtek also make a WSPR receiver, but I can't really see its advantage, over and above a much more general coverage SDR receiver, which will provide much more interest to the owner.  The one thing that's needed, really, is a field WSPR receiver that doesn't need an associated laptop, which use a lot of power and are expensive, with an on board connection to the mobile network, so that spots can be reported live.  Either that, or on board storage, for later uploading of spots.

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