SQ5BPF notes – Page 2 – radio, electronics, security, silly hacks

2021-08-122021-08-13

SV9/SQ5BPF with uSDX part 2

So I’ve tried to operate from Platanias / Crete (see SV9/SQ5BPF with uSDX part 1).

Threw a wire on a palm palm tree, stretched a counterpoise on the ground, tuned it, and made the first CW QSO on 40m with Zygi SP5ELA. So next I’ve tried to tune the antenna on 80m, and the uSDX transceiver failed with a short circuit.

It seems that the smd PA transistor died on 80m (it also dies on 10m). Fortunately I’ve had two IRLML2060 transistors with me, but no soldering iron and other tools.

So is there any hope that i will be able to make more than one QSO?

Continue reading “SV9/SQ5BPF with uSDX part 2”

2021-08-012021-08-12

SV9/SQ5BPF with uSDX part 1

I have traveled to Crete / SV9 in July 2021 for vacation. I’ve spent vacation in Greece many times. This time i brought a shortwave transceiver with me to see if amateur radio will be compatible with a family vacation.

Continue reading “SV9/SQ5BPF with uSDX part 1”

2021-02-072021-02-14

Low cost operating on QO-100 CW

One of my new year’s resolutions for 2021 was to make some contacts via the QO-100 satellite.

This would normally require equipment like an ADALM-PLUTO or other transmit-capable SDR, transverter, power amplifiers etc. This is necssesary for SSB and other modes, but for CW it should be much easier and cheaper.

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2020-12-05

Etherify 5

Another etherify article, this time transmitting via a covert channel from an air-gapped network by controlling switch ethernet interfaces via SNMP.

See:

Etherify 5 – switching the switches

2020-11-30

Linksys LGS318 serial console pinout

Linksys LGS318 serial console pinout:

Continue reading “Linksys LGS318 serial console pinout”

2020-11-272020-11-27

Etherify 3 and 4

I’ve added two etherify articles to the Soft TEMPEST series, one showing an exceptionally strong signal radiated from a raspberry pi 4b, and another showing that regular ethernet hardware can also be used.

Please see:

Etherify – bringing the ether back to ethernet

Etherify 3 – the PI 4’s dirty little secret

Etherify 4 – back to earth with “normal” ethernet hardware

2020-11-162020-11-16

Sonify

I’ve published Sonify. This is a script to transmit data via ultrasound Morse code. Please see: Sonify – transmitting data via ultrasound morse code

This is another article in the Soft TEMPEST series. Please see also:

Etherify – bringing the ether back to ethernet

2020-11-12

Moxon antenna for 125MHz

I’ve always wanted to make a Moxon antenna, but didn’t have an excuse to do so. Recently i needed a very lightweight directional antenna for Etherify with not so much gain, but considerable F/B, so i finally had the excuse i needed.

Continue reading “Moxon antenna for 125MHz”

2020-10-312020-11-10

TR-9000 CW semi-BK mod

To transmit CW on the Kenwood TR-9000, TR-9130, TR-9300, TR-9500 (and maybe other) transceivers one has to hold the PTT on the microphone (or on the optional BO-9 base) and only then transmit using the KEY. For some reason the Kenwood thought this would be an excellent idea.

This is a simple external semi-BK circuit implementation, so that you can just press the key to transmit. No modifications inside the radio are necessary.

The circuit is connected to the STBY (2.5mm jack) and KEY (3.5mm jack). Connect the key to the CW KEY terminals. To increase the time make the capacitor bigger, currently it is 3000uF (3x 1000uF in parallel). The diodes are any silicon diode like 1N4148, 1N914, 1N4001 etc.

Keep in mind that the capacitor is charged to 8V, so that the key has temporarlily 360mA flowing thorugh it. No problem for a straight key, but it might be an issue with some electronic keyers.

See the circuit in action here:

VY 73 de SQ5BPF