Hi Steve and the group:
At 02:02 PM 1/21/97 -0800, you wrote:
>I had some questions about putting a fan in the Omni-6.
>
>I began the search for a quite fan. None filled the bill. Even the
>smallest ones were quite audible. I tried putting a resistor in series
>with a few of them. Running a 12vdc fan at 6vdc really made them quite
>but they were reluctant to start up at that voltage.
>
Yes, unfortunately quiet fans for anything from ham radio equipment
to boatanchor size computers are hard to come by at the "right"
operating characteristics. The major problem is that fan noise
generally is proportional to cooling capacity. Then add the cost
component and you can see why fans can be a tough decision for an
equipment manufacturer.
>I stumbled upon a junked out Hewlett Packard laser printer at work which
>had a 24vdc fan. Applying 12vdc, I was amazed how well it started up and
>how quite it was. I removed the aluminum bracket from the Omni-6,
>removed the little speaker (which I never used anyway), broke off the
>studs, drilled a couple of holes and mounted the fan in the speaker
>hole. 12v was easily obtained from the final's power lead. The air
>exhaust through the speaker grill. The fan was virtually inaudible and
>just a faint whisp of air emmits from the speaker grill. Inside, the rig
>stayed perfectly cool even under the heavist operation. BFO drift was
>eliminated.
Excellent solution. I have also made note of the concern over
ambient heat causing BFO drift and will deliver to the engineering
department so they can mull it over.
See you all in the 160 contest this weekend.
Scott Robbins, W4PA
Ten-Tec
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