I agree with the EFHW being a good portable antenna.l, especially if you don't run an internal or external tuner. You could even make and add an inexpensive loading coil with about 9.5' of wire at the end to get 80m. I know the 891 doesn't have an internal tuner but if you had a tuner, a 9:1 unun with 72' of wire can be matched with a tuner to get all bands 80-10m. I also use the Gabil Antenna GRA 7350T (available under other brand names) which is a base loaded verticle, with 4 16.5' radials. Does well for being a compromised antenna. Not necessarily cheap (tripod is extra) but is a quick set up. Could even be used with a mag mount on a vehicle.
My quick thoughts.
Andy (also)
KC3WRX