The condenser serves more than the purpose of radio RFI suppression. Any condenser or capacitor serves the purpose of 'absorbing' energy spikes. This means that it essentially prevents, or at least heavily reduces the amount of arcing between regulator contacts as they rapidly switch on and off. It also helps prevent arcing in the generator brushes. Radio noise is caused directly by this arcing, so noise suppression is actually a secondary function of the condenser.
The condenser connected in the ignition system function in most the same way. First and foremost it prevents the points from arcing every time they open and close, and as stated above, a reduction in arcing not only saves the contact points but prevents noise in the radio.
In some cases, what you'd find is a condenser mounted close to the regulator itself for factory 'radio-delete' cars and trucks... and to further suppress RF interference an auxiliary condenser was installed on the generator. One engine can have as many as 4 condensers: 1 in the distributor, 1 on the positive side of the coil, one on the regulator, and one on the generator armature.
So the moral is don't make the mistake of omitting the all-important condenser just because you don't have a radio! No good can come from omitting these, and it doesn't hurt to have them in absence of a stock radio.
