Hi,
In my dual conversion receiver, I have a 45.455MHz second LO and a 45 -
75MHz first LO.
First IF 45MHz second IF 455KHz
Both these feed double balanced diode 7dBm mixers.
Also I have not filtered these signals at all, and the first harmonic is
roughly -20dBc - -30dBc.

Is it imperitive that I filter these for my receiver to work?
If so by how much?

Best regards,
John.