Miscellaneous Hardware Projects...

Here there are some of the general the projects I am working on.

Note, I moved some of the projects to the new Arduino page (see menu on the left).

"GenSeq", a generic sequencer board

Präsentation in der ÖVSV Landesverband-Sitzung Kärnten im Dezember 2018 (German only, sorry): download PDF

Genaue Beschreibung im DUBUS 4/2018! Detailed description in DUBUS 4/2018! (ext. link)
Title: Little helper for various control tasks / Kleines Helferlein für vielfältige Schaltaufgaben

Following setups are possible with the default firmware, measured w/o load on the PA output.
First wave is control in/out, second is PA output, third is REL1 out, fourth is REL2 out.
Units shown are Volts and Seconds.

Latching, common -, slowLatching, common -, fast
Latching, common +, slowLatching, common +, fast
Failsafe, slowFailsafe, fast
(press right mouse button on a picture and then select "show picture" or similar in your browser for a bigger view)

Get here the PDF with a basic description (German only, sorry): download

Here is the actual FW release as Intel HEX file for updating your sequencer board. It can be flashed using any Atmel ISP hardware and software to the GenSeq board. Note, the processor on the board is running on 5V supply. PLEASE DISCONNECT ANY LOADS FROM THE BOARD BEFORE FLASHING!

You can download this software at your own risk and for non-commerical purpose only. Please do not distribute, but refer to my web page to ensure any updates are received if available. One goal of the project was to be useful. Nevertheless, if you use it, you are responsible for any direct or indirect damage caused by this hardware or software, so use it with care please. If you agree to this terms, click here for download: GenSeqV1_Release_1.0.0.zip, otherwise please just leave it alone.

Here are the GERBER files I use for my production, so you can produce PCBs yourself if you like (non-commercial use only!): again, download and use at your own risk.
I still have some PCB left and can sell them with a pre-programmed ATTINY13A for 4,5€ plus packaging and shipping costs. 3,0€ for the PCB alone.

I also have a few prototype boards which look similar (and are fine w/o the PA output) I can give away together with an pre-programmed ATTINY13A for 3,5€ plus package/shipping.

I can also pre-configure the ATTINY to one of the above settings and check on a test board if you wish. Special versions on request, eveything is based non-commercial use "according to ham-spirit", I do this in my free time and w/o commercial interest. Contact me for details.

PTT-Control via ZF on a Yaesu FT-817ND for transverters from DB6NT, LZ5HP, DL2AM, etc.

The FT-817ND (and probably the FT-818 as well) can be simply modified to support RX/TX switching directly using the ZF connection to the transverters. There are several solutions available, I decided to use a very simple one which works out really well now for my second season using this moficiation for all my transverters I have (from 23cm to 122Ghz).

This is implemented by using the TX5 line within the FT-817ND and connect them via a 10kOhms resistor to the BNC connector of the rig. For DC decoupling the original HF line is connected via a high quality 10nF capacitor. If you are concerned of HF on this supply, you may add a small inductor in series to the resistor as well. I didn't do that and have not noticed any issue yet.

Not a lot to say about, see the pictures how I have done the mod. Of course, do your own rework at your own risk, you can easily damage your FT-817ND or potentially also your transverter(s)! So if it does not work, don't try over and over again but do some simple measurements: do the parts you soldered have the right value? Disconnect everything and measure the resistor value and capacitor with an RLC meter. In operation, press PTT shortly and check if one side really shows the 5V voltage while you are on transmit (with a proper 50 Ohms load connected, of course). I guess latest to this point you should be able to identify the problem.
(press right mouse button on a picture and then select "show picture" or similar in your browser for a bigger view)

I could not find the actual service manual of the FT-817ND, so newer versions use even more SMD parts on the PCB. Nevertheless it is rather easy to map this pictures to newer versions of the rig.

My experiments with microwave antennas from 1-24 GHz (mostly Vivaldi)

...more to come!


Stay tuned ;-)