Something you could do is to have a separate groupo, but remain members of the same club. So the club would have two fields, and two groups of fliers.

If the fields are close enough that there's a fear of signal crossing, you can arrange a freq cutoff - That is, you make a list of all of the freqs that the guys who are flying electric are using, And a list of the freqs everyone else is using. See where you match - Let's say that twp electric fliers have the same freqs as some of the glow fliers - since you are the smaller group, and you are the ones trying to keep the peace, all of the electric fliers could pitch in to buy those two guys crystal sets that don't interfere with the glow guys.

Then, you establish a rule that channels 16, 24, 43, and 50 (or whatever they are) are banned from use at the glow field, and the electric field can use ONLY those freqs.

From then on, if someone wants to fly glow, they will have to buy crystals. By the same token, if a new glow flier joins the club and has a banned freq, he'll have to change (It would be no different than if there was serious radio frequency problems on that channel at a given site)