Informações do equipamento
|Cushman Electronics Inc. CE-5 Communications Service Monitor|
Cushman Electronics Inc.
|Grupo:||Communications Service Monitor|
1.01 The Cushman CE-5 Communications monitor accurately measures the frequency of the output of FM or AM transmitters. The range of measurement is from 20 MHz to 519.999 MHz. It also measures the frequency deviation of the modulated output of these transmitters, and using the Model 313 plug-in the percentage of AM may be measured. 1. 02 The CE-5 functions as a signal generator covering the same range of 20 MHz to 519.999 MHz with the same accuracy as in the Monitor mode- The output level Is calibrated from 0.1 to 100 microvolts. The output may be either FM, AM or CW and the modulation and level are both adjustable. Modulation, both FM and AM, is from an internal 1 kHz source. Modulation from an external source, 60 Hz to 20 kHz, may also be used for both AM and FM. In addition both Internal and external modulation may be applied simultaneously. 1.03 In the IF Frequencies mode signals from 1 kHz to 40 MHz are available at a separate output, with the same accuracy as the generator. Level is adjustable but not calibrated. These IF Frequencies may be used for alignment and troubleshooting of receiver IF and audio circuits. 1.04 In the generator mode the CE-5 may be used to align and check the sensitivity of receivers. Since both internal and external modulation may be used simultaneously or several external modulating frequencies may be summed and used to modulate the output, the instrument may be used for testing and aligning of tone operated receivers. 1.05 When a measurement of the received frequency with greater resolution is required a counter may be connected Co the 100 kHz IF OUTPUT connector. This output is 100 kHz * the error of the signal with reference to the dialled In frequency. The accuracy now will be the accuracy of the CE-5 Master Oscillator crystal frequency = the accuracy of the counter. GENERAL DESCRIPTION 1.06 The CE-5 is a specialized VHF/UHF superheterodyne receiver. With it a transmitter can be monitored for correct carrier frequency and amount of modulation deviation. The assigned transmitter carrier frequency is "dialled in" and the actual carrier frequency of the received signal Is compared with an internally generated standard. This standard is the local-oscillator (LO) frequency. 1.07 When the incoming signal is of sufficient amplitude, a frequency error detector is activated and a meter shows the difference between the assigned carrier frequency and the actual carrier frequency. Discriminator circuits are also turned on which provide an indication (on a Deviation Meter or Oscilloscope) of frequency deviation. 1.03 The CE-5 must be operated with either a Cushman Model 301 Oscilloscope or a Model 302 Deviation Meter inserted into the left-hand plugin compartment, and the broadband mixer, one of the RF Preselectors or one of the other available plug-ins in the right hand compartment. 1.09 The incoming signal is received at the antenna connector of whatever RF plug-in is used and a first intermediate frequency (IF) signal is produced with a frequency that is 10 MHz ± carrier frequency error. LO frequency = dialed in frequency ±10 MHz. Dialed in frequency = assigned carrier frequency, therefore the difference between the LO frequency and the actual carrier frequency is 10 MHz ± the carrier frequency error. The LO frequency may be either 10 MHz above or below the dialed In frequency. 1.10 The first IF signal is mixed with a stable 9.9 MHz signal from the Master Oscillator (MO) to produce a second IF signal with a frequency of 100 kHz ± carrier frequency error. The error is detected and displayed on the FREQUENCY meter. 1.11 The second IF signal is also demodulated and the resultant audio frequency signal is amplified in the Deviation Meter or in the Oscilloscope to give an indication of the amount of FM deviation present due to the modulation on the received carrier. 1.12 In the Signal Generator mode the LO is used for the output signal, but is shifted ±10 MHz so that the output frequency will be the same as the dialed In frequency.' This 10 MHz shift is automatically taken care of by mixing an internally generated 10 MHz signal with the LO. This 10 MHz signal can be modulated, either FM or AM, or left unmodulated for CW output. Modulation is by an internally generated 1 kHz signal or may be from an external source, or both may be used together. 1.13 The level of FM, AM or CW signals generated by the CE-5 is controlled by attenuators which are calibrated to give an output of between 0.1 and 100 microvolts through a 20dB fixed attenuator which is supplied with the Instrument. This fixed attenuator should be used for protection, but approximately 10 times more signal is available.
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|Cushman Electronics Inc. -- CE-5 -- Serviço e Manual do Usuário|
|Tipo manual:||Serviço e Manual do Usuário|
|Tamanho:||24.31 Mbytes (25487804 Bytes)|
|Data:||01 Janeiro 1975|
|Qualidade:||Documento Scaned, a leitura parcialmente mal, não parcialmente legível.|
|Upload de data:||07 Agosto 2017|
|Downloads:||55 desde 07 Agosto 2017|
|Iniciar Download grátis|
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