Cubic CDR-3250 Receiver Power Supply Refresh
The Cubic 3250 VLF-HF receiver is a 10kHz – 30 MHz DSP based radio receiver with 51 IF bandwidths and 7 receive modes. It falls into the category of professional/military grade equipment and the build quality certainly reflects this. According to Fred Osterman’s book, “Shortwave Receivers Past and Present, 3rd Ed.”, it was manufactured from the mid 1990s until at least 1998 (possibly later). I have found that the audio recovery and readability of this receiver is outstanding.
As both of my units were made in 1995/96, they are 25 years old and likely have thousands of hours of use. So I elected to replace all the electrolytic capacitors in the power supply with (arguably) an abundance of caution. I first measured the voltage and ripple on the output rails: