New kit: HF band pass filters for receiver input tuning

These kits are now available priced $4.90 (4.33€ or £3.38), for all 10 HF bands from 160m to 10m inclusive. They use the popular double-tuned-circuit band pass filter topology because over the years I have found it to be reliable and un-fussy. Each tuned circuit consists of a toroidal inductor in parallel with a capacitor. The capacitor is made of a fixed component and an adjustable trimmer in parallel. A band-pass filter at the input to your homebrew receiver or SDR will typically improve the performance, usually quite considerably, by excluding some of the strong signals which can otherwise cross-modulate with your wanted signal.

The BPF kits have the same PCB size 1.5 x 0.5 inches (38 x 13mm) and pin header footprint as the QRP Labs LPF kits, so that they can also be used with the relay-switched filter kit.

VE3KCL balloon flights

Dave VE3KCL's S-9 balloon flight was mentioned in the April newsletter. In the end it flew for 18 days. It came within a matter of a few hours of reaching its Toronto starting longitude. Indeed, it would have flown past quite close to Toronto! But tragically it was brought down by a storm reaching up to high altitude. Circumnavigation wasn't to be, this time!

The S-10 flight was launched on 09-May-2016. Unlike S-9, it crossed the Atlantic quickly, without loops. Unfortunately it has GPS problems since day 2, making the position reports very infrequent. The last WSPR position report from the balloon put it in Bulgaria heading for the Romanian border. But the last transmission decoded from the balloon was on 14-May-2016. It may still be flying, but with transmissions off-frequency and off-time because of the lack of GPS to correct the frequency and time.

ZL1RS Ocean Floater

Bob ZL1RS has put a U3S kit on an ocean buoy! See Tracking is by WSPR (conventional, not telemetry) and JT9. It is currently being carried to a launch position a few days sail from New Zealand, to avoid currents that would push it back to the ZL-land beach. The launch from the yacht Windflower is due imminently! Thereafter, this transmitter will go wherever the currents take it. Progress will be a lot more sedate than the balloon flights. This is another fascinating tracking project, with a different set of challenges compared to a balloon. Good luck Bob!<

New U3/U3S firmware versions

There were a couple of minor releases with a bug fix.

v3.09f (for U3 or U3S kits) fixed a bug with the GPS info setting not being saved properly in EEPROM. It also fixed a problem present sine v3.09d, which locks up the U3 when you have multiple WSPR transmissions configured and you are using the old AD9850 DDS.

v3.10a (for U3S only) fixes the same bug with the GPS info setting not being properly saved in EEPROM. v3.10a is only for the U3S kit (not older AD9850 DDS kits).

As usual, these are available for download from the folders in the QRP Labs YahooGroups forum, or for purchase in the QRP Labs shop.

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