PARADAN AMPFAN

Automatic/Manual Cooling Fan

For Power Amplifiers

This is a fan to assist in the cooling of RF poweramplifiers. It allows the amplifier torun closer to continuous duty without endangering the output tubes. The fan sits ¾ inch above the amplifier’s airexhaust vent and increases the air flow across the output tubes.

The fan runs on the shack’s 12 volt supply. Plug the RED Powerpole into + 12 Volts, andthe BLACK connector to common. Ifreplacing the connectors with your own, remember the red wire is positive.

The three position switch operates as follows: the centerposition power is OFF. When switched tothe right the fan is ON continuously.When switched to the left the fan is in the AUTOmatic mode. It will turn ON when the amplifier’s airexhaust reaches a temperature of 105 degrees F.The fan will stay ON until the temperature returns to below 105degrees. The sensor’s heat is retainedfor a considerable time to allow the switching to conform to the long term air,and tube, temperature.

The temperature sensor is a thermal switch using a bi-metalcontact that makes and breaks at its design temperature. In the auto position the switch is placed inseries with the 12 volt power lead.

The fan is a commercial unit using a brushless motor. It takes about 300 mA when connected to 13.5volts. The fan is quiet; the sound level is only 70 dB A-weighted SPL.

With the increased use of digital transmission modes, such asPSK-31, JT65, Slow scan TV, RTTY, and others, the power amplifier runs in acontinuous operating state. Theamplifier’s output tubes become hotter than on CW or SSB. Additional cooling is necessary for long tubelife. The AmpFan is a welcome additionfor the contester and the dxpeditioner, especially in hot climates.

Shipping: 1.2 lb. viaUSPO fixed price $6.00

Specifications: Operating voltage: 10 -15 V dc

Current: 300 mA @ 13.8 Volts

Size: 4.75 x 4.75 x 1.5 inches

Noise: 70 dB SPL

Madein USA