Radio Transceiver bulkhead connection and Ground
Usually the antenna ground will still be effective when connected via a (say) 1000pF capacitor. Reason: the capacitor acts like a short circuit at high enough frequency. A 1000pF capacitor at 50MHz has an impedance of 3 ohms.

I don't know what frequency you are using so the actual capacitor value depends on the application but generally this can be a way of keeping isolation from any low frequency currents that would otherwise pass through the transceiver and cause it problems. It would certainly block DC and this may be the bigger issue such as when using a positive ground supply.

On the other hand, the transceiver may work perfectly fine when grounded to the chassis.

Another option is to use an RF isolation transformer in the feed to the antenna.