AM Radio Systems Trainer

AM Radio Systems Trainer

AM2961

The AM Radio Systems Trainer comprises a pair of open-boards:- the AM2961A, an AM/DSB/SSB generator and the AM2961B, an AM/DSB/SSB receiver.

The AM circuits operate within the AM broadcast band and the DSB/SSB circuits operate within the 80mm 'ham band'. The generator output is only a few milliwatts, so the range of transmission is extremely limited and no licence is required.

The receiver has an integral antenna, but may also be used, with the addition of an external antenna, to receive normal broadcast and amateur signals. The principles and techniques of AM with full carrier, doublesideband suppressed carrier and single-sideband suppressed carrier transmission and reception can be easily investigated.

Switched faults may be introduced on both generator and receiver units. On the receiver, fault options include disabling of mixers, local oscillators, audio amplifier and beat frequency. Other faults include fast/slow and min/max gain AGC faults. Switches on the generator disable audio source, AGC of audio source, MW local oscillator and modulator, SW carrier oscillator, modulator, SW mixer and SW local oscillator.

• Features

  • Covers the principles of AM radio signal generation and reception
  • Double sideband carrier
  • Double sideband with suppressed carrier
  • Single sideband with suppressed carrier
  • Receiver operating at 500 -1600kHz (MW) and 3 - 4MHz (SW)
  • One fixed generator frequency in each band
  • Transmission medium may be coaxial cable or very limited range on-air
  • Transmission power very low, less than 10mW
  • Extensive use of monitor points for signal tracing
  • Switched faults on both generator and receiver

• Subject Area

  • Familiarisation and On-Air Reception
  • Amplitude Modulation and Frequency Changing
  • Envelope Detection and Automatic Gain Control (AGC)
  • Double-Sideband Transmission and Reception
  • Single-Sideband Transmission and Reception