I`ve just built a magnetic loop for 20m, it is 1 metre circumference
and
uses a coaxial capacitor (RG58... QRP operation!!!) , it receives
very
well but doesn`t transmit very well at all !!!!.....it loads but
T/X isn`t
up
to R/X.....

Any advice will be greatly appreciated.....

==============================
There's almost certainly nothing the matter with it.

You can't expect a small QRP magloop to work as well as a 1/2-wave
vertical with 100 watts.

What makes you think it is not working as well as it ought to? What
have you compared it with?
----
Reg, G4FGQ