I noted desensitization and its effect on a repeater system. Desensitization is especially evident when transmitter operation coincides with nearby rcvr functions. Isolation is important to consider when desensitization occurs during TX/RX functions. There are a few fixes to think about when this problem manifests.
This afternoon, I'm learning about capture effect in relationship to frequency-modulation (FM) and amplitude-modulation (AM). There are differences as suggested in the license manual. Noise and interference affect an incoming signal according to Wolfgang, Reed, and Jan Carman (2007).
Capture Effect.
FM behaves differently when noise or interference are present. The loudest signal on the frequency will be demodulated unlike AM, SSB, or CW. This characteristic is capture effect as suggested by Wolfgang, et al. (2007). Is this true about FM in one's vehicle? Because the authors note that capture effect is advantageous when one is trying to receive a loud station when weaker stations occupy the same frequency. The manual further explains noise and interference effects on AM, SSB, or CW signals (p 4-28).
Wolfgang, et al. (2007) added a few suggestions as well.
- Limiter and discriminator stages in FM reception eliminate most impulse-type noise. Are they speaking about one's vehicle when referencing impulse-type noise?
- They suggested one's receiver intermediate frequency (IF) system and detector phase tuning must be properly aligned for notable noise suppression. [note: what is limiter stage, discriminator stage, and detector phase tuning?]
Time for me to answer the questions.
Reference: Wolfgang, D. L., Reed, G. D., and Jan Carman, R. (2007). [8th ed.] Extra Class License Manual. ARRL-The national association for amateur radio. Newington, Ct. 06111.