Is a heatsink required on FT8 mode?

One of the challenges with digital modes is their higher duty cycle than phone or CW.   However, Ashhar Farhan VU2ESE, designer of the µBITx, assures us that on FT8 the standard heatsinks supplied with the kit are adequate.  FT8 has a 50% duty cycle.

This may not apply with other digital modes such as WSPR.


A month of FT8

Yesterday was when Tom  AB7WT completed his first month of using his uBITx on the air and it’s been 100% FT8.

After one month, Tom has had 252 FT8 contacts!

This has been achieved with a modest random length end-fed 59 ft antenna with one end up in a tree.  He’s worked 80m, 60m, 40m, 30m, 20m, 17m, & 15 meters.

Almost all contacts have been using 4 watts or less. The results have
been great.  It includes 45 of 50 US states confirmed toward Worked All States (WAS).   He is still trying to nail down those last 5 states.  Tom has worked New Zealand, Australia, Russia AS, Samoa, Cuba, Japan,
and Canada.

So, he’s been very happy with FT8.  He’ll be even happier when
the sunspot cycle turns upwards …..:)

Are there other happy op stories out there?


GPS and digital modes

Many digital modes (such as WSPR and FT8) require reasonably price clocks which may be assisted by GPS technology.

Hans G0UPL  observes that WSPR does not require GPS. However:

1) WSPR requires precise frequency, the transmission must be within the 200Hz WSPR sub-band.

2) WSPR requires precise timing: transmissions start on the 2nd second of even minutes, +/- a few seconds. An ordinary crystal or worse still, the ceramic resonator on some Arduinos, will not provide sufficient timing accuracy to run WSPR for long.

A GPS is a very convenient and easy way to achieve both of these objectives. On the Ultimate3S kit the latitude and longitude are also converted to Maidenhead Locator which is encoded live, into each WSPR transmission. Something that is necessary if you want to use WSPR for tracking something (ship, balloon) for example the Canadian C3 expedition

Speaking of which: Jim N2NXZ’s U3S-22 balloon (running modified Ultimate3S firmware) reached Kazakhstan today. For the second time! It’s already been flying for 23 days, at a little over 9,000m altitude, and completed one world circumnavigation! See for details and live tracking (using WSPR) during daytime. Big congratulations to Jim!


WSJT-x release addresses Linux issues with uBITx

JP Bhatnagar, VU2SPF, has advised the list that the anticipated announcement  of a new version of WSTJ-X has been  made by Joe Taylor of the WSTJ-X development team. This mentions addressing ubitx transceiver connectivity with WSTJ-X.   WSTJ-X  has become very popular with amateur operators, as it implements the exciting new FT8 digital mode.
The full announcement follows:

The WSJT Development Group is pleased to announce a third Release Candidate of WSJT-X Version 1.9.0.  A second release candidate, v1.9.0-rc2, has been tested in the field over the past three weeks, including a public test of FT8 DXpedition Mode conducted on March 6-7.

A General Availability (GA) release of v1.9.0 will be announced at a suitable time, probably in the near future.  After that time you should stop using any -rc# release candidate.

Here’s a short list of features and capabilities added to WSJT-X since Version 1.9.0-rc2:

1. Corrected a number of flaws in Fox behavior, FT8 DXpedition Mode

2. Allow Hounds to use compound callsigns in FT8 DXpedition Mode

3. Write debugging information to FoxQSO.txt

4. Fix the “Blue Decode Button” bug

5. Allow partial processing of incoming UDP Reply messages so that non-CQ/QRZ decodes can be processed. The processing is the same as double-clicking the same decoded message within WSJT-X except that “Enable Tx” will not be enabled.

6. Send DX grid locator to wsjt_status.txt, for use by applications like PstRotatorAZ

7. Correct the display of DXCC status of KG4 calls

8. Updated copy of cty.dat

9. Updates to documentation

10. Updated Hamlib functionality including changes to the Yaesu FT-817  back end that allows the uBITx kit transceiver to be CAT controlled by WSJT-X.

10. Other minor bug fixes