Wireless Troubleshooting Hints

Date Updated: March 6, 2012 FAQ #5330
Question:
Wireless Troubleshooting Hints
Answer:


Troubleshooting Wireless Microphone Systems



 



Even when wireless microphone systems appear to be properly selected and set up, problems may arise in actual use. While it is not practical here to offer comprehensive solutions for all possible situations some general guidelines are suggested.



Though problems with wireless microphone systems eventually show up as audible effects these effects can be symptoms of audio and/or radio problems. The object of troubleshooting in either situation is first to identify the source of the problem and second to reduce or eliminate the problem.



The following abbreviations are used below:




AF = audio frequency



RF = radio frequency



RFI = radio frequency interference



TX = transmitter



RCV = receiver




 



A common symptom in multiple system operation is apparent activation of two receivers by a single transmitter. This can be due to one of several causes: operating frequencies the same or too close, crystal harmonics, transmitter at the image frequency of the second receiver, IM with an unknown source, etc. If activating the second transmitter results in proper operation of both systems this effect can usually be ignored. Recommended operating procedure is to turn up a receiver only when its transmitter is active. If it is desired to allow open receivers without transmitters, readjusting the squelch settings may suffice. Otherwise the operating frequencies may have to be changed.






















































































































































































Troubleshooting Guide



Conditions: TX on, RCV on, single system

Symptom

TX - RCV
Distance

Possible cause

Action

No AF signal and no RF signal

any

low TX battery voltage

replace battery

No AF signal and no RF signal

any

TX and RCV tuned to different frequencies

retune one or both units

No AF signal and no RF signal

average

multipath dropout

use diversity RCV or reposition TX and/or RCV

No AF signal and no RF signal

long

out of range

move TX closer to RCV

No AF signal but normal RF signal

any

TX muted

un-mute TX

No AF signal but normal RF signal

any

microphone or other input source

check input source

Distortion with no AF peak indication

any

low TX battery voltage

replace battery

Distortion with AF peak indication

any

excessive TX input level

decrease source level or TX input level

Distortion with AF peak indication in subsequent equipment

any

excessive RCV output level

decrease RCV output level

Noise with low AF signal and normal RF signal

any

insufficient TX input level

increase source level or TX input level

Noise with low AF signal and normal RF signal

any

strong RFI

identify source and eliminate, or change frequency of wireless microphone system

Noise with normal AF signal and low RF signal

average

moderate RFI

increase squelch setting until RCV mutes

Noise with normal AF and RF signals

any

very strong RFI

identify source and eliminate, or change frequency of wireless microphone system

Intermittent AF signal and low RF signal

long

out of range

move TX closer to RCV

Intermittent AF signal and low RF signal

long

insufficient antenna gain

use higher gain antenna

Intermittent AF signal and low RF signal


long



excessive antenna cable loss

use low loss cable and/or less cable

Intermittent AF and RF signals

average

multipath interference

use diversity RCV or reposition TX and/or RCV

Intermittent AF and RF signals

average

obstructions in signal path and/or RCV

remove obstructions or reposition TX

Intermittent AF and RF signals

average

squelch set too high

decrease squelch setting

Intermittent AF and RF signals

average

very strong RFI

identify source and eliminate, or change frequency of wireless microphone system

When multiple systems are in use some additional problems can occur due to interaction between the systems. Turning individual systems on and off and trying systems in different combinations can help to pinpoint the cause. However, this can become much more difficult as the number of systems increases.


Following are some multiple system troubleshooting suggestions for symptoms observed when all systems are active.
 



Conditions: TX on, RCV on, multiple systems

Symptom

Distance

Possible cause

Action

Distortion on two (or more) systems with no AF peak indication

any

units on same frequency

change frequencies

Distortion on one (or more) systems with no AF peak indication

TX-TX short

TX + TX intermod

change frequencies

Distortion on one (or more) systems with no AF peak indication

TX-TX short
TX-RCV short

TX + TX intermod
TX + TX + RCV intermod

increase TX to TX distance
change frequencies

Distortion on one (or more) systems with no AF peak indication

TX-RCV short

TX + TX + RCV intermod

increase TX to RCV distance