Dual VFO Radio Issues

Recommendations for radio equipment at EOCs and hospital command centers call for using multiple radios, one for each net that needs to be continuously monitored. It is possible to monitor two nets with a dual-VFO radio, but we don’t recommend this. When you transmit on one VFO of a dual-VFO radio, you may not be able to hear traffic on the other VFO. This is effectively being away from one of the nets without checking out, and should be avoided.

Some dual-VFO radios allow reception on one VFO while transmitting on the other, IF the two are tuned to different bands. However, you cannot guarantee that the two nets you need to monitor will always be on different bands. And even when they are, reception is likely to be worse while transmitting, and may not be adequate. (Receive noise level may be increased, and sensitivity may be decreased, due to insufficient isolation between the VFOs.)

Having a second radio also provides a measure of rendundancy against equipment failures. A station that expects to need to monitor multiple nets during an incident should be resilient.

This is not to say that dual-VFO radios are bad. The second VFO of each radio can be used for other nets that don’t need continuous monitoring, or as backups. But ideally a station should have a separate radio for each net that needs continuous monitoring.