I do quite a bit of my QRP operating from portable locations. I like to use use simple wire antennas but, truth be told, I really dislike spending my limited operating time trying to get antenna wires up into trees. I much prefer to have an antenna that I can set up (and tear down) quickly so I can spend more time on the air. I also like set-ups that are self-contained and don't require a lot of real estate. This set-up fills the bill.
What I did was modify my homebrew roll-on mast support so I could use my hitch-mounted bicycle rack to support it. This only required the drilling of two holes in the roll-on mount. Figure 1 shows the roll-on mount clamped into the bike rack. In this case, I was supporting a 31-foot Jackite pole. After extending the pole and removing the bottom cap, I just lower the pole onto the 1-1/4 inch pipe. That's all there is to it. Figures 2 and 3 show the Jackite pole mounted to the bike rack.
By selecting the right size of pipe, I can use this technique to support a variety of masts. For example, I've used this type of mount to support two 5-foot sections of TV antenna mast. I used this configuration to support a 1.2 GHz beam for DStar digital communications during an ARES-RACES drill a while back.
When operating QRP-portable, I often use a vertical antenna made from a 30-foot piece of hook-up wire and fed through a homebrew 9:1 unun with a 18-foot length of RG-8x coax. As shown in Figure 4, the unun is just attached to the pole using some small bungee cords. No radials are used, which gives this set-up virtually a zero footprint. You can find more information on this configuration on the EARCHI website. I've successfully used this antenna in the field over the past few months. I'm sure it's a bit of a compromise, as antennas go, but it seems to work pretty well. The extra height using the bike rack mount seems to help performance a bit. (Although I can't quantify that, I sure the extra height doesn't hurt.)
I used this particular antenna configuration on the bike rack for the first time during the October Polar Bear Moonlight Madness Event (PBMME). Within 10 minutes of my arrival in Valley Forge Park, I was on the air making contacts. When it was time to leave, I was packed up in about 5 minutes. Now, that's what I'm talkin' about!
73, Craig WB3GCK