A: You could have a compound problem. Let’s take the Lionel no. 167 whistle controllers first. They may not be performing adequately. Very few of these old units that are still functioning perform up to original factory specs. A high percentage of them don’t work at all, having succumbed to terminal diseases such as herniated rectifier discs or inflammation of the choke coil – both irreversible conditions. Others are casualties of owner abuse or simply have expired of old age.
I suggest having your controllers tested by a Lionel service station to find out if they have slipped seriously below specifications over the years. Or you can experiment, substituting other 167s in your layout circuit until you find a pair that work well.
Your choice of transformers could contribute significantly toward your overall problem. Although well made, American Flyer transformers simply don’t provide enough track voltage to be used successfully with Lionel whistle equipment. They may be of substantial wattage rating, but they were designed to deliver a maximum of only 16 volts to the track.
Lionel transformers of the “outboard whistle controller” era all kicked out 20 to 24 volts, because the mere insertion of a no. 167 controller into the track circuit causes an automatic 4- to 5-volt reduction in power at the track. If your 167s are ailing even slightly, they may be sucking up still more juice. You do the math.
It will probably boil down to this: You either keep your American Flyer transformers and abandon using your whistle equipment, or break down and buy transformers that were designed to handle it.