National RFs Type ATF Power Attenuators were designed to allow interfacing of linear power amplifiers to RF exciters, where a specific amount of drive to the amplifier is prescribed. Often, however, drive from the RF exciter exceeds this minimum prescribed level and some form of power attenuation must be used in order to not damage the input of the power amplifier. National RFs type ATF-3 offers 3 dB of power attenuation (1/2 of the power) when used between the exciter and the amplifier and will handle an input power of 132 Watts, RMS (continuous power) while providing about 66 Watts RMS output power, when it is terminated into 50 ohms. In practice, the ATF-3 attenuator will handle exciters achieving Peak Envelope Power levels (PEP) in the area of 200 to 250 Watts while providing half of that power to the load. For less attenuation requirements, the ATF-1 and ATF-2 offer 1 and 2 dB of attenuation, respectively.

The units are made with common metal film resistors, configured in a series/parallel combination to achieve the required power and attenuation ratings, while maintaining an affordable price for the user. With the use of metal film resistors, all types present non-inductive characteristics to the source and load. Although designed for standard 50 ohm impedances, the actual impedance will be between about 48 and 52 ohms, due to the tolerances of the metal film resistors. The ATF series are of the T-Pad attenuator design.




Amount of power attenuation: Type ATF-1 1 dB
Type ATF-2 2 dB
Type ATF-3 3 dB
Maximum Input Power: 132 Watts, RMS (slightly higher for
Types ATF-1 and 2)
Attenuator Design Type T-Pad, Bi-Directional
Input/Output Connectors SO-239 (UHF Female)
Enclosure Mechanical Size: 4 X 2 1/8 X 1 5/8
(Not including the connector projections)
Operational Frequencies: DC to 50 MHz. (Units will operate above
this frequency with reduced attenuation

Price: $89.95 plus a shipping and handling charge of $7.50 for shipping to United States addresses via US Postal Service. Overseas orders will require additional shipping charges, to be determined after receipt of order. CA residents must add their local state sales tax rate to the price of the product (shipping charges excluded).

Power Attenuators ATF $89.95 $7.50

OVERSEAS CUSTOMERS: Please contact National RF for the shipping charge and delivery schedule to your country.

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