Fans for Spectra D44 UHF radiofor low power repeater -

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Joined: Sun Apr 06, 2003 6:38 pm
What radios do you own?: MCS2000, MTX9250, XPR7550e

Fans for Spectra D44 UHF radiofor low power repeater -

Post by k3td »

What is the best way to mount 2 cooling fans to D44 UHF dash mount Spectra set to 15 watts for use as the transmitter in a desktop repeater? I was thinking about one fan on each side PA heat sink with one blowing across the PA and the other blowing away from the PA. Thanks in advance for the advice!
Tad, K3TD
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Joined: Sun Sep 09, 2001 4:00 pm

Re: Fans for Spectra D44 UHF radiofor low power repeater -

Post by Jim202 »

The transmitter heat sink needs to be cooled enough to hold your hand on it after say 5 or 10 minutes in transmitting. Warm is OK. But too hot to keep your hand on it is very bad.

You need to know that these radios were never designed for 100 percent transmit time. All mobiles will have a time limit of like 10 percent.

What I would suggest is to turn on the TX time out timer and set it for like 3 minutes with the fans blowing air over the heat sink. This will force users to keep their transmissions short. It won't solve the original problem. But will kill the transmitter until it looses the PTT keying line.
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