MK,

So you use the same Amateur Radio Antenna
for the 160m and 80m Bands as you do for the
6m and 2m Bands.
http://en.wikipedia.org/wiki/Amateur_radio

160-Meter Amateur Band = 1.815 to 1.89 MHz
80-Meter Amateur Band = 3.5 to 3.8 MHz
6-Meter Amateur Band = 50-54 MHz
2-Meter Amateur Band = 144-148 MHz

MK # 1 - " An antenna is an antenna is an antenna. "

But A Piece of Wire - Now That's Electrical ! )

MK #2 - "Do you think when I switch from a SWL
to a ham band, I need to switch antenna types? "

MK - As an Amateur radio Opperator - If you were using
a 20-Meter Dipole Antenna to Talk Coast-to-Coast
http://www.chem.hawaii.edu/uham/20.html
-or- a SkyWire {NVIS} Loop Antenna for your local-area "Net" Work
http://groups.google.com/group/rec.r...c8553f4137bb58
http://groups.google.com/group/rec.r...1803362ae6952f

http://groups.google.com/group/rec.r...73213a11be0b83
http://groups.google.com/group/rec.r...01f389f911c57d

- - - Then just may be you would want to switch over to an 45
to 100 Foot Inverted "L" Shortwave Listener's (SWLs) Antenna
to be able to Hear-Around-the-World from all directions with ease.
* 45 Foot Shortwave Listener (SWL) Inverted "L" Antenna
15 Foot Vertical Up-Leg with a 30 Foot Horizontal Out-Arm
* 100 Foot Shortwave Listener (SWL) Inverted "L" Antenna
25-33 Foot Vertical Up-Leg with a 67-75 Foot Horizontal Out-Arm
http://groups.google.com/group/rec.r...92a8ef6391bce6

MORE "LN-ILA" READING = http://tinyurl.com/j9erj
Note - LN-ILA = Low Noise Inverted "L" Antenna - a la John Doty


just - keeping it simple and practical {KISAP}
cause - iane ~ RHF