I was running my TMCC setup and started to reflect on an earlier work experience. In the 1960's, there were no licenseable radio frequencies for general household R/C systems. However, the frequencies below the AM broadcast band (540KHz) were not restricted. As a result, a radio controlled garage door opener was introduced that operated in the available non controlled low frequency RF spectrum. Widespread preexisting use of the LF spectrum eventually created some issues for the product and it was subsequently withdrawn from the market. Those spectrum uses still exist today. More currently, the FCC has recently allocated some frequencies in the LF spectrum for amateur radio use that are near the TMCC track frequency. What effect this could have, if any, is difficult to predict.
