Shaun Merrigan's Information Pages


Tag: Cubic 3250


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 »


Cubic Communications CDR-3250 VLF-HF Communications Receiver Fan Noise Solution Part II

Posted by Shaun Merrigan in Premium Receivers, Tech. Comments Off on Cubic Communications CDR-3250 VLF-HF Communications Receiver Fan Noise Solution Part II

12th October

Cubic Communications CDR-3250 VLF-HF Communications Receiver Fan Noise Solution Part II

This post will furnish additional detail about installing a quieter and more efficient rear panel fan in the Cubic Communications CDR-3250 VLF-HF Communications Receiver.

As I mentioned in the previous post, the duct/standoff/adapter can be made from wood. I chose solid pine because I had some in my offcuts box; plywood would be a good choice too.

The dimensions of the duct are: 75mm H x 60mm W x 15mm D as shown:

The holes are 55mm diameter (fan side) and 45mm diameter (receiver grille side). The hole on the receiver side had to be smaller in order to accommodate the 42mm bolt hole pattern of the OEM fan, while leaving enough material around the fastener holes for a sound mechanical joint. In addition, I happened to have 45mm and 55mm hole saws … Read More »


Cubic Communications CDR-3250 VLF-HF Communications Receiver Fan Noise Solution

Posted by Shaun Merrigan in Premium Receivers, Tech. Comments Off on Cubic Communications CDR-3250 VLF-HF Communications Receiver Fan Noise Solution

9th October

Cubic Communications CDR-3250 VLF-HF Communications Receiver Fan Noise Solution

I recently had the opportunity to acquire a Cubic Communications CDR-3250 VLF-HF Communications Receiver (two, in fact), fully functional, in very good condition. This is a very high quality, mil-spec receiver using DSP for the final IF, giving a large selection (51 possible, depending upon the mode) IF filters. It is stable, selective and has one of the best menu systems I have used in a receiver. Also the the audio quality and audio recovery is the best I have heard this side of a tube radio like the R390A or SP600JX. Oh yes, stereo headphones work (mono in both ears) properly from the headphone jack.

The receiver incorporates a small box fan in the rear of the chassis to pull air through cooling the modules and power supply (also at the rear). … Read More »