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”

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