[Premium-Rx] Fw: Fan noise

[Michael O'Beirne]

>
> Gents
>
> A typical example of unacceptable fan noise is on the very rare STC 
> STR8212 HF receiver.
>
> The basic problem was misdesign of the packaging.  As a digital receiver 
> it uses a lot of power yet the height of the chassis in only 2 rack units. 
> The airflow from the rear-mounted fans blows air past the hot sections and 
> into the receiver and it exits via 2 vents by the front panel.  The design 
> is silly.  The hot air should be blown out of the receiver!
>
> A significant amount of air has to be moved within a confined volume and 
> thus powerful but small fans are used which generate a really horrible 
> noise.  I suspect these sets were mounte din one room near the aerials and 
> the operator was far away via the remote link.
>
> The owner tried fitting quiet computer fans but they could not achieve the 
> same air flow and he had to revert to the original noisy fans.  If it were 
> my set I might fit an external fan and blow the air in via a Hoover type 
> of wide flexible pipe, but that's quite a lot of messy plumbing.
>
> I have gone back to an analogue Racal RA3701 that runs cool.
>
> 73s
> Michael
> G8MOB
>