Information on an Avantek X-band GaAsFET preamp

In the early 90's, some X-band GaAsFET preamps appeared on the surplus market.  Primarily sourced by Avantek and manufactured in the the 1986-1987 time frame, these were reportedly used in the AN/APG-68 (see the related Wikipedia article) fire-control X-Band RADAR on jet fighters and bombers - namely the F-16C/D fighters and possibly the B-1B bomber.

For some reason, these units were obsoleted and pulled from service and those held as spares were released as surplus.  While likely a misfortune to the taxpayer in general (the reported cost of these units was in the $3k-$4.5k range each) they were a boon to those interested in experimentation on the 10 GHz amateur radio band.

Note:  Preamps of this model were acquired and made available by another Utah ham in the early 1990's and a number of them were sold to members of the San Bernardino Microwave Society (SBMS) and reportedly referred to as the "Utah Preamp."  Since this source has dried up (all of them were sold) they are probably not readily available.
The X-band GaAsFET preamp - suitable for 10 GHz amateur radio use.
Click on image for a larger version.

These units are variously labeled, but one variation is as follows:

FETAMP - XM213303
additional designation included may be:
On the data sheet, the model number is SA85-2079G and the part number is 585R600H04

The NSN (National Stock Number) would appear to be:  1270-01-153-8700WF

Note:  If you "Google" the above NSN you can divine additional information about the application of this preamplifier module.

While few "official" specifications are available for these amplifiers, some general information was obtained form the manufacturer.

What is not shown on the data sheet: Having used one of the amplifiers on my homebrew 10 GHz transverter, I have made several observations:

Pinout information:

For normal operation (e.g. high gain mode, noise test disabled) pins 5 and 12 are tied to ground (pin 2.)

It has also been observed that the amplifier appears to work properly with just a single positive supply connected at pin 1 in the range of 12-15 volts.  The additional supplies appear to be required only if additional features (such as the gain control, noise test) are needed.

Typical Voltage/current consumption from the test data:

Additional specifications from the test data:

Misc. Notes:

Note:  This preamp was second-sourced by at least one other manufacturer:  Information on that unit will be included if/when it becomes available.

This page last updated 20121002

Since 12/2010: