Frequently a simple frequency modulator circuit comes in really handy in RF design, test, modules etc. Signal Processing Group Inc., recently released a PCB based FM modulator using a 200 Mhz to 400 Mhz VCO. ( Other frequency ranges may be available). The board has the VCO, a DC bias input to set the rest frequency of the VCO, a high pass RC network for the modulating signal and input and output BNC connectors. The supply voltage is 3.3V to 5.0V. Interested parties may contact Signal Processing Group Inc, either through the website or directly by email at spg@signalpro.biz.