Q. Intermittency and poor distance We have trouble with intermittency and poor distance. We would like some systematic way to determine if it is due to environment or truly a problem with the FM system itself. A. If FM users are experiencing intermittency or poor range, most of the time it is caused by interference in the form of signals generated by computers, electronic equipment and electrical appliances. Interference of this type occupies a wide band and can blank out an entire frequency spectrum. It only stops when the offending equipment is turned off. To check whether this is the problem, simply take the FM system outside the building to see if the interference disappears. If it disappears, switch off electrical equipment in the building one by one until the offending equipment has been found. If a channel (frequency) is occupied by another FM user, the easiest way to avoid interference is simply to change the frequency of your FM system. Q. Static interference Driving in a car I notice that power stations or high voltage lines create unwanted static in my FM system. Can something be done to avoid this static interference?
A. The FM receiver is not able to differentiate between the signal from your personal transmitter and the signal from a high voltage line on the same frequency. So there is unfortunately nothing you can do. Q. PC workstations and FM A client tells me that he gets interference on one of the channels if he gets close to some (not all) PC workstations in their office. Have you heard reports of this before?
A. Yes we have had a few reports about interference from PC workstations. There are some PC’s around that are not as shielded as they should be, and these PC’s can cause interference. If the FM system has to be used in close connection to a PC that causes interference, the best chance of getting rid of the interference is to try another channel (frequency) Q. Poor Operating distance We sometimes have customers who complain about reduction of the FM signal, once they leave the room where the transmitter is used. I know that signals can be reduced due to metal constructions, doors, etc, in between transmitter and receiver but I need more detailed data.
A. First of all, we have to remember that the MicroLink FM system is not a walkie-talkie system for communicating between two rooms. MicroLink FM system is a wireless system that help hearing instrument users in difficult listening situations. Listening situations where a normal hearing person can understand speech, but where the hearing instrument user cannot. Normal communication distance is typically within one room, and here the MicroLink system will typically have an operating range of 7 - 15 meters. In many instances it is possible to receive a signal from one room to the other, but as soon as the transmitter is in one room and the MicroLink receiver is in another room, we cannot always guarantee good reception, because there are so many things that can have influence on the FM transmission. Things that are not under our control. The operating range also depends on the condition of the batteries in the FM transmitter/receiver/hearing instrument, as well as local interference and radio transmission conditions which may be affected by building design, metal walls, doorways etc. So, a general guideline for how far the system should work? I would say: "Within a normal size room,- minimum 7 meters". I am sure that in most cases the operating range will be much more than that. |