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

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 »