# Why is it difficult to localize shortwave transmissions?

I have read that it is difficult to localize shortwave transmissions, but I don't understand why that is. I know that localizing the bounced transmission is obviously difficult, but when the antenna radiates, it will also radiate locally, so I would guess that local direction finders would be able to easily find the transmitter, just the same way that they would find a VHF transmitter. Is there some reason why that is not true?