QRPGuys SMT Digital Dial/Frequency Counter
This product has been retired. Bare board only available – $10, Go here to order
We have some extra boards. We are offering the pc board only for those that would like to source their own parts for this project. The firmware for the PIC16F628A is available for download in our Misc. Flies page, and the parts list and assembly instructions are available in the manual.
The QRPGuys SMT Digital Dial/Frequency Counter is the same circuit and operation as our original through hole model, except it uses SMT components and has a much smaller footprint. It is a small five digit led digital dial kit with optional programmable I.F. frequency offsets. It can also be used as a standalone frequency counter. It is only 2.00”W x 1.00”H. Thickness can either be .42″ or .55″ depending on which side you choose to mount the pushbutton switch and calibration variable capacitor. The usable range is 100Hz-50MHz. It has a low current usage (~20mA), and a high impedance input. Limit the input voltage to 2.0V. The kit comes with all stainless steel mounting hardware, nylon spacers, and a red Mylar lens for mounting inside your chassis. This kit is not recommended for first time SMT builders. We assume you know how to assemble SMT components. The circuit used is basically a DL4YHF counter V2 with the extra digit and 2N3904 preamp, packaged to fit neatly within your project case. A Google search will reveal numerous display variants and modifications for experimenters for over a 10 year evolution by Wolf. There have been many diverse mods., prescaler, extra digits, RS232 port communication, etc. by others worldwide around this clever code. Use this as a platform for your experiments, improvements and share with others.
Connections are made to your device via .100” header pins, or use the positions as solder pads. The tools required are a soldering iron with a small tip, rosin core solder, small side cutters, and can be built in an hour or two. On a difficulty scale of 1 to 5, 5 being the most difficult, this is rated at 5.
100Hz-9.999 kHz – x.xxx
10kHz-99.99 kHz – xx.xxx
100kHz-999.9 kHz – xxx.xx
1MHz-9.99 MHz – x.xxxx
10MHz- 50.00 MHz – xx.xxx (x.xxxx with programming trick) see manual p. 6