Most handheld receivers are designed to be used with a very short duckie
antenna. The front end is totally overwhelmed if connected to an antenna
of reasonable size. Besides having a whole lot of extra gain to
accommodate the short antenna, compromises have to be made in the front
end filtering because of the unit's small physical size. Keeping the
power consumption low further limits the dynamic range of the stages.

I have an Icom R1 and it's full of crossmod birdies even with its own
antenna. When connected to a real antenna, it's totally unusable, the
front end being overloaded and blocked by just about anything. I have to
use a 20 or more dB pad if I ever connect it to a decent antenna. I'll
bet a substantial attenuation pad would do wonders for yours.

Roy Lewallen, W7EL

Ceriel Nosforit wrote:
. . .
The R5 has an attenuation function that sometimes is a bit of help...
Maybe the entire receiver is getting overloaded, causing some sort of
overmodulation? The signals are pretty strong after all...

Thanks for the replies!