Shaun Merrigan's Information Pages


Category: Radio


Cubic CDR-3250 Receiver Power Supply Refresh

Posted by Shaun Merrigan in Electronics, Radio. Comments Off on Cubic CDR-3250 Receiver Power Supply Refresh

9th January

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:


Cubic CDR-3250 Display Replacement

Posted by Shaun Merrigan in Electronics, Radio. Comments Off on Cubic CDR-3250 Display Replacement

9th January

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.

These receivers have a VFD (vacuum fluorescent display) as part of the front panel/human interface. The VFD in one of my units must have had many, many hours on it because it was quite fuzzy and dim, to the point of being blurry:

Aged, dim, blurry VFD

The old display on the CDR 3250 showed considerable burn in when viewed using … Read More »