Topband: Raised radial question from NH

[Jim F.]

Nothing heard this morning in NH at 1530Z.

Am in a condo environment where invisibility is a factor.
Antenna is an Inverted L  fed through a series capacitor with 
two #22 ga. raised radials 136' long ~ 10 feet high running
through the woods which have stayed up 2 days so far.

One question :

Do you think that thin radials could cause an increase in receiver noise ?

Another question :

The 50 ohm feedline line is 25' long connected directly to the rig.
Is isolation needed to preserve the effectiveness of raised radials ?
If so, what would the isolation consist of ?

73

Jim / W1FMR / QRP