INSTRUCTIONS MODEL AVMR-2-PS-ECL-ED-EO-EA-EW-M-N-PN-TRF-FOICA PULSE GENERATOR S.N.: __________________________________________________________________ 2 WARRANTY Avtech Electrosystems Ltd. warrants products of its manufacture to be f ree from defects in material and workmanship under conditions of normal use . If, within one year after delivery to the original owner, and after prepai d return by the original owner, this Avtech product is found to be defective, Avtech shall at its option repair or replace said defective item. This warran ty does not apply to units which have been dissembled, modified or subjected to conditions exceeding the applicable specifications or ratings. This wa rranty is the extent of the obligation assumed by Avtech with respect to this pro duct and no other warranty or guarantee is either expressed or implied. TECHNICAL SUPPORT Phone: 613-226-5772 or 1-800-265-6681 Fax: 613-226-2802 or 1-800-561-1970 E-mail: World Wide Web: __________________________________________________________________ 3 __________________________________________________________________ 4 TABLE OF CONTENTS WARRANTY............................................................... ...............................2 FIG. 1: PULSE GENERATOR TEST ARRANGEMENT............................5 GENERAL OPERATING INSTRUCTIONS......................................... ......6 POWER SUPPLY AND FUSE REPLACEMENT...................................... 9 PERFORMANCE CHECK LIST................................................ .............11 Manual Reference: /fileserver1/officefiles/instructword/avmr/AVMR-2-PS- ECL-ED-EO-EA-EW-M-N-PN- TRF-FOICA, edition1.doc, created January 28, 2002 __________________________________________________________________ 5 FIG. 1: PULSE GENERATOR TEST ARRANGEMENT 40 dB 120/240V attenuation 50-60 Hz Out Sampling AVMR-2-PS-FOICA Scope In RL = 50 Ohm Trigger Output Pulse Generator PRF: 0 to 5 MHz PW:  100 ns AMP: ECL -0.8 and -1.6 Volts __________________________________________________________________ 6 GENERAL OPERATING INSTRUCTIONS 1) The bandwidth capability of components and instruments used to display the pulse generator output signal (attenuators, cables, connectors, etc.) should exceed ten gigahertz. 2) The use of 40-dB attenuator will insure a peak input signal to the samp ling scope of less than one volt. 3) In general, the source pulse generator trigger delay control should be set in the 0.1 to 1.0 us range. The stability of the display on some sampling scop es is very sensitive to this delay, particularly at high PRF. 4) When testing using a general-purpose 50-Ohm laboratory pulse generator as the input trigger signal source, the input signal should be applied via a 5 0-Ohm feed- through load or alternatively, the input to the AVMR unit should be shu nted with a 50-Ohm resistor. This will prevent reflection (and degradation of th e input pulse waveform) caused by the high impedance at the IN port. 5) The input trigger pulse width should be greater than 100 ns and less th an one half of the pulse repetition frequency period. The unit triggers on th e leading edge of the input trigger signal. 6) The rise and fall time are switched from the high (3.0 ns) to low (0.3 ns) range by means of the TR and TF two-position switches (TRF option). 7) The output pulse width is controlled by means of the one-turn potentiom eter (PW). The pot should initially be set maximum clockwise and the pulse width adjusted using an oscilloscope. 8) The output pulse amplitude is controlled by means of the one-turn poten tiometer (AMP). Rotation of the PW pot causes the position of the falling edge of the pulse to change. CAUTION: For some pulse width settings, some pulse w idth jitter may be observed. This jitter can be removed by applying +5VDC t o the rear panel “Lock” solder terminal. With +5VDC applied, the pulse width cont rols are disabled. 9) To voltage control the output pulse width, set the rear panel switch in the EXT position and apply 0 to +10V to Connector A (R  IN 10K). (EW option). 10) To voltage control the output amplitude set the rear panel switch in th e EXT position and apply 0 to +10V to Connector A (R  IN 10K). (EA option). 11) Some properties of the output pulse may change as a function of the amp litude pot setting. For some demanding applications, it may be desirable to us e a __________________________________________________________________ 7 combination of external attenuators and the amplitude pot to achieve th e desired output amplitude. 12) The AVMR output pulse position or delay can be varied for up to 5 ns by means of the delay (DELAY) control. Rotating the delay control clockwise inc reases the delay. If the full 5 ns delay cannot be achieved then the input pulse width should be increased by a few nanoseconds. (option) 13) To voltage control the output delay set the rear panel switch in the EX T position and apply 0 to +10V to Connector A (RIN  10K). (EA option) 14) For units of the OT offset option, the output DC offset level is varied from –5 to +5V (to 50 Ohm) by the front panel OFFSET one turn control. The DC offs et may be turned off using the rear panel OS ON-OFF toggle switch. (OT option) . 15) For units with the EO option, the output offset may be voltage controll ed by setting the rear panel switch in the EXT position and applying 0 to +10 volts to Connector A (R  IN 10K). 16) To invert the output of the AVMR unit, connect the AVX-3-T unit to the OUT port. An inverted pulse is then obtained at the OUT port of the AVX-3-T unit. To offset the inverted pulse, apply the required DC level to the DC terminal of t he AVX-3-T unit. 17) M ONITOR Output: Provides an attenuated (x10) coincident replica (to 5 0 Ohm) of the main output. (option). 18) W ARNING : Model AVMR-PS may fail if triggered at a PRF greater than 5. 0 MHz. Also note that the duty cycle must not exceed 10% (eg. 20 ns at 5 MHz, 200 ns at 0.5 MHz). 19) AVMR units with a serial number higher than 5600 are protected by an au tomatic overload protective circuit which controls the front panel overload lig ht. If the unit is overloaded (by operating at an exceedingly high duty cycle or by ope rating into a short circuit), the protective circuit will turn the output of t he instrument OFF and turn the indicator light ON. The light will stay ON (i.e. outp ut OFF) for about 5 seconds after which the instrument will attempt to turn ON (i.e . light OFF) for about 1 second. If the overload condition persists, the instr ument will turn OFF again (i.e. light ON) for another 5 seconds. If the overload condition has been removed, the instrument will turn on and resume normal operati on. Overload conditions may be removed by: a) Reducing PRF b) Reducing pulse width c) Removing output load short circuit (if any) __________________________________________________________________ 8 Note that the overload light may illuminate when the prime power is fir st applied. The light will extinguish after a few seconds and the instrument will t hen function normally. 20) The unit can be converted from 120 V to 240 V / 50-60 Hz operation by a djusting the voltage selector card in the rear panel fused voltage selector cabl e connector assembly. 21) For additional assistance: Tel: 613-226-5772 Fax: 613-226-2802 Email: __________________________________________________________________ 9 POWER SUPPLY AND FUSE REPLACEMENT This instrument has three main fuses, plus two spares. One, which prote cts the AC input, is located in the rear-panel power entry module, as described in the “Rear Panel Controls” section of this manual. If the power appears to have failed, check the AC fuse first. The other two fuses (plus two spares) are located on the internal DC po wer supply, as shown below: Negative Power spare OK LED fuses Negative DC fuse Positive Positive DC fuse Power OK LED The positive fuse and one of the spare fuses on this circuit board are 1A slow-blow fuses, Littlefuse part number R452001. (This fuse can be ordered from D igikey, The Digikey part number is F1343CT-ND). The negative f use and the second spare fuse are 0.5A slow-blow fuses (Littlefuse R452.500, Di gikey part number F1341CT-ND). If you suspect that the DC fuses are blown, follow this procedure: __________________________________________________________________ 10 1. Remove the top cover, by removing the four Phillips screws on the to p cover and then sliding the cover back and off. 2. Locate the two “Power OK” LEDs on the power supply circuit board, as illustrated above. 3. Turn on the instrument. 4. Observe the “Power OK” LEDs. If the fuses are not blown, the two LED s will be lit (bright red). If one of the LEDs is not lit, the fuse next to it ha s blown. 5. Turn off the instrument. 6. If a fuse is blown, use needle-nose pliers to remove the blown fuse from its surface-mount holder. 7. Replace the fuse. (Spare 1 Amp and 0.5 Amp fuses are provided on the circuit board. They may be transferred to the active fuse locations using needl e-nose pliers.) __________________________________________________________________ 11 P ERFORMANCE CHECK LIST __________________________________________________________________ Document Outline * [1]WARRANTY * [2]FIG. 1: PULSE GENERATOR TEST ARRANGEMENT * [3]GENERAL OPERATING INSTRUCTIONS * [4]POWER SUPPLY AND FUSE REPLACEMENT * [5]PERFORMANCE CHECK LIST __________________________________________________________________ References 1. file:///root/tmp.html#2 2. file:///root/tmp.html#5 3. file:///root/tmp.html#6 4. file:///root/tmp.html#9 5. file:///root/tmp.html#11