I found a couple of products that used 72MHz. Most did not, as you say. It could be that they are legacy uses, again, as you say. However, the potential remains for their use.

I thought the following, originally offered up by BasinBum might be useful to everyone. I had never seen it before:

"Author: Don Ayers
Hello R.C. Nuts!

Ever have the problem of people showing up at your hill with unmarked channels on their transmitters? You ask for their channel, and they say, "Um, 72.810?"

The frequency is not readily useful in preventing a disaster, is it?

Here's a interesting conversion that, once memorized, can me done in a few seconds in your head. You can then amaze your friends as you call out their correct channel number from just hearing the frequency!

Here goes:


Take the hundredths from the frequency (72.810; use just "81"
Subtract 21 (81-21=60)
Divide by 2 (60/2=30)
Add 21 (30+21=51)
You're done. The answer is channel 51!
This can also be reversed, and yield the frequency when only the channel number is known, although this is less useful at the field:

Take channel number (51)
Subtract 21 (51-21=30)
Multiply by 2 (30x2=60)
Add 21 (60+21=81)
Put 72. in front of the answer (72.81)

By remembering these conversions, the answer is immediately available when needed, and no one has to scramble for a full page channel chart when some yahoo is threatening to turn on an unmarked transmitter!
Hope this is of interest to some out there - happy flying! "