Verticals for 30, 40, 80m

[VK5ZD]

The CHA250 uses a large "power swallow" resistor plus a balun effect so that the returned SWR looks ok to the transmitter if the basic feed impedance of the active vertical section varies widely from anything acceptable."

There's no resistor in the CHA250, but it still doesn't work very well. It's easy enough to "roll your own" if you have a suitable vertical element.
If you want to spend some money then I'd go with a vertical sitting on an auto-tuner (e.g. EDX-2) with whatever ground radials you can manage.

73
Iain