Today lots of basic entry-level boats come with modern 2.4 gig radios. Believe me, they are far superior to the old 72/75 hHz radios, with much less interference and usually less latency. Plus the wheel radio is easier for children to use.

I understand the attraction of repurposing what you have, but in this case current radios are superior. You can get a boat without a radio and pick up a used 2.4 transmitter/receiver cheap on eBay.

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