Ok gents, heres the rig first.
AN/PRC-104 HF radio, two BB5590 LiON milspec batteries
Antenna- 15Ft manpack Whip (didnt have my AT-984 wire reel)
Just wanted to throw my fun for the night out there. Next- Time to get my general!
Good on you for trying! One thing i will say - dont get downhearted if you dont have great success. Ive seen people get ex-mil manpacks, then complain they cant work people. They seem to forget that these sets are not designed for working weak amateur signals, they are designed to be robust and survivable in battle conditions! Your signal with 20w to a manpack whip is going to be weak, much as my 100w to my mobile whip is often week. Take a look at what the military use on the other end of the link! Rarely is a skywave contact from a manpack expected to be received by another manpack, they use a comcen with BIG antennas! The hard work of the contact is done by the fixed (or temporary) big antennas of the communications center.
So, whats my point? Look for nice, BIG signals! Take the VK3 i heard yesterday - S9 +40dB at my mobile station in the UK. His antenna? 4x 5el stacked beams for 20m!
Have fun, but let the big guns do the hard work!
Using 10m, or 20m and up, is a good idea, as your making the most of the short antenna