How to use the Retic Amplifier

foreword

Some time ago, no one used the Retic power amplifier in the laboratory, and some students said that they would not use it, so the instructor sent me and another classmate to do a brief research, so this article came into being.

Retic Amplifier Instructions

---

• When Retic is used as a power amplifier, there are currently two working modes to choose from:

  Method 1 : The signal is generated inside the device, and then amplified and output (this article focuses on method 1)

  Method 2 : Connect an external signal source, amplify the power of the device, and then output (the signal output of this method is a bit unstable, the first method is recommended)

---

Method 1 using steps:

1. Connect the cables correctly

   • The power cord is connected to the rear of the chassis (next to it is the main switch of the power amplifier) ​​as shown in the figure (above)
   • RF Pulse Monitor interface to connect oscilloscope (for monitoring output voltage)
   • The High Power RF Pulse Output interface is connected to an impedance of 150 ohms
   • The above 150 ohm impedance is connected to the transducer , as shown in the figure below (below)
     
     

2. Turn on the power of the Retic power amplifier and set the internal signal source parameters

   • Before the signal source is set, High Voltage Control should be disabled

   • Set the parameters of the built-in signal source: adjust the LCD display to the PULSER page (as shown in the ellipse in the figure below)

     • FREQ Set the frequency (the frequency should be consistent with the center frequency of the transducer)
     • PW CYCLES Set the number of cycles
     • PW USEC does not need to be set, it will automatically change according to CYCLES, which indicates the duration of the BURST pulse, and the unit is microseconds (usec)

   • Set the repetition frequency of the power amplifier and the input mode of the signal source : adjust the LCD display to the TRIGGER page (as shown in the figure below)

     • TRIG is set to INT, which means internal signal source

     • RR sets the repetition frequency , which indicates how often the power amplifier transmits a Burst pulse, and the duty cycle of the pulse must be less than $1\%$ (as shown in the picture below)

       
       • Therefore, assuming that the signal source frequency is 1MHz and the number of cycles is 10, then:
         • $t_1=1us\times 10=10us$, $\frac{t_1}{T_1}\le 0.01$, $T_1\ge 1000us$ , if in$Hz$ is the unit, that is,$RR\le 1000Hz$
         • That is to say, the above RR setting should be less than or equal to 1000; the calculation of other frequencies can be done as above
       

3. After the setting is completed, the output can be amplified

   • Adjust the LCD display to the PULSER page (as shown in the picture below)

     • Set TRACK to Y (Yes)

   • Adjust CONTROL to 000 or the lowest value

     • CONTROL only indicates a degree of magnification, 0 is the smallest and 100 is the largest

   • Turn on Enable of High Voltage Control , then adjust the oscilloscope to monitor the amplified signal

     • Because the output monitored by the oscilloscope is attenuated by $40dB\; ,\; so\; after\; the\; oscilloscope\; display\; is\; enlarged\; by\; 100\; times,$ the actual amplified voltage output is shown in the figure below:

       

4. At this time, slowly adjust the CONTROL to perform power amplification. After use, properly arrange the instrument and power supply

---

If this article is useful to you, you can like and bookmark this article. It will be much easier to find next time you use it. It would be great
if you can follow the author. The author will continue to learn, output, and share! Thank you for your encouragement!