UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Memories and other stories from Pye etc PMR engineers.

Biggles · 15th Sep 2017, 5:12 pm

A long time ago in a previous job we used to look after radio deaf-aids for school children. The teacher wore a little low power FM transmitter, and the hearing impaired pupil had a receiver fitted with an earpiece based on one of the commonly available radio chips at the time (I think it was an MC3361). This worked fine most of the time, but on occasion we had problems other than the usual dropped/got wet scenarios. One complaint was from a pupil who kept hearing strange voices in their earpiece. Every time we checked it out it in the workshop it was fine and this went back and forward a couple of times until we did a site visit and saw that the school was near a mast. We worked out the frequencies and found that the deaf aid receiver was on a direct image frequency for what I think was a local taxi firm. We gave the school a different channel colour, and all was well! The receivers weren't the most selective but most of the time we got away with it. I just kept imagining the poor kid trying desperately to convince his teacher that they were hearing strange voices.
Alan.

15th Sep 2017, 5:12 pm	#37
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Re: Memories and other stories from Pye etc PMR engineers. A long time ago in a previous job we used to look after radio deaf-aids for school children. The teacher wore a little low power FM transmitter, and the hearing impaired pupil had a receiver fitted with an earpiece based on one of the commonly available radio chips at the time (I think it was an MC3361). This worked fine most of the time, but on occasion we had problems other than the usual dropped/got wet scenarios. One complaint was from a pupil who kept hearing strange voices in their earpiece. Every time we checked it out it in the workshop it was fine and this went back and forward a couple of times until we did a site visit and saw that the school was near a mast. We worked out the frequencies and found that the deaf aid receiver was on a direct image frequency for what I think was a local taxi firm. We gave the school a different channel colour, and all was well! The receivers weren't the most selective but most of the time we got away with it. I just kept imagining the poor kid trying desperately to convince his teacher that they were hearing strange voices. Alan.