10 GHz Linear Translator

    On April 7, 2002 with help from Lars AA6IW we installed a 10 GHz linear translator at the site of the
    Stanford Amateur Radio Club W6YX (CM87wj).  This site will only be used for initial testing and burn-in of the
    translator.  After initial testing the translator will be relocated to a higher peak such as Monument Peak (CM97bl)
    or Mission Peak where the coverage area should be considerably better.

    The translator is mounted on a leg of the W6YX east tower, the transmit antenna is on top and the receive antenna
    is on the bottom. The antennas are seperated by 11 vertical feet providing over 100 db of isolation between them.

Currently the antennas have minimal weather protection, just a single layer of Kapton tape over the slots.Before relocating a more rugged mounting arrangement and better weather protection for the antennas will be required.  The characteristics of the linear translator are:
 

 Power Consumption 48 volts, 0.7 amps
Input Frequency Range 10368.608 - 10368.648 MHz
Output Frequency Range 10369.208 - 10369.248 MHz
Maximum Output Power 500 milliwatts
Beacon Frequency 10369.208
Beacon Power 50 milliwatts
Rcv. and Xmit. antenna gain 10 dbd
Control Link 440 MHz FM / DTMF
Location CM87wj   525' asl
System Gain (including antennas) > 130 db, 60 db agc range
The noise floor of the receiver is set 20 db below the beacon power.  It's quite likely that most stations will be able to hear the 40 KHz wide passband noise of the receiver.  Several of the translator parameters can be remotely controlled over the 440 MHz FM control link:
 
Transmitter             On / Off
Receiver                 On / Off
Transmit power      High / Low (500mw / 50mw)
System Gain           High / Low ( >130 db / > 90 db )
2nd LO                  Translating / Non-translating
It will be interesting to experiment with the transmit power and system gain on various paths to see how much margin is available.  Due to project creep the weather proof box wound up completely packed. Here's a photo of the final system:

Thanks to Bob Melvin W6VSV for measuring the slot antenna patterns on his excellant homemade antenna range.Here are the azimuth and elevation patterns for one of the slot antennas (click on the thumbnail for a larger image):
 
 Slot Antenna Measured Patterns

A presentation on the translator that was given at a  50 MHz and Up Group  meeting is here: slides

Please send me email of reception reports of the beacon, QSOs through the translator or suggestions for changes and improvements.

- Gary AD6FP