On 7/3/10 23:27 , m II wrote:
D. Peter Maus wrote:

Many SW portables do have adequate sensitivity to perform well below
30 Mhz with the built-in whip, or a fairly short length of wire. More
than 20 feet on many can lead to overload issues on some rigs.

But for handheld widebands, an longer antenna is needed. There are
many options available. I've seen and used whips of a meter or more in
length for HF on my R-10. A bit cumbersome, but not bad performance. An
external antenna that connects to the BNC mount on the rig is useful for
mobile monitoring. And some fixed base operations.

For a while, Grove made a rubber ducky with an amplifier for HF that
works quite well on better handheld widebands, like those by ICOM and
AOR, Yupiteru and others. I have one and it's a nice performer down to
MW. No longer made, but the circuit is fairly simple. It can easily be
replicated.


I've read that many of those so called 'DC to Daylight' portables
aren't that hot on shortwave. Have you heard of anything in that
respect? It would be nice to have it computer controlled, for the ease
of a frequency database.



mike




As I said, the antenna is usually too short. Sensitivity is
actually quite good, though. Comparable to a decent desktop. But
antenna capture area is insufficient. So, SW performance out of the
box is pretty lame. My R-10 was worthless on SW until I began using
a larger antenna.

That said, all but the Yupiteru are too wide for SW. Sometimes as
much as 12Khz on AM. SSB, though the IF bandwidth is usually
acceptable.

For highly portable SW, I'll slip my HF-150 into my camera bag,
with a whip, and tote it out into the woods.