Using redux-observable and subscribing to a websocket

Trying to figure out how to get my epic going which will subscribe to a websocket and then dispatch some actions as the emitted events roll in from the websocket.

The sample I see are using a multiplex and not actually calling a subscribe on websocket, and I'm confused a bit on changing it up.

I have started it like this. But I believe the redux observable is wanting an

const socket$ = Observable.webSocket<DataEvent>(
  "ws://thewebsocketurl"
);

const bankStreamEpic = (action$, store) =>
  action$.ofType(START_BANK_STREAM).mergeMap(action => {
    console.log("in epic mergeMap");
    socket$
      .subscribe(
        e => {
          console.log("dispatch event " + e);
         distributeEvent(e);
        },
        e => {
          logger.log("AmbassadorsDataService", "Unclean socket closure");
        },
        () => {
          logger.log("AmbassadorsDataService", "Socket connection closed");
        }
      )
  });

   function distributeEvent(event: DataEvent) : void {
        //this.logger.log('AmbassadorsDataService', 'Event Received: ' + event.command + ' and id: ' + event.id);
        if(event.source === '/ambassadors/bank') {
            if( event.command === 'REMOVE') {
                removeDataEvent(event);
            }
            else if(event.command == 'ADD') {
                loadDataEvent(event);
            }
        }
    }

It is throwing an error: Uncaught TypeError: You provided 'undefined' where a stream was expected. You can provide an Observable, Promise, Array, or Iterable.

Any help would be appreciated!

Thanks