[HomeBrew] Torroids in vacuum tube circuits

[rrfowler at bellsouth.net]

Can't remember if this has been discussed before, but has anyone ever tried using ferrite or iron core toroids instead of solenoidal air wound coils in plate and grid tuned circuits before?? I have been pondering building a HB vacuum tube receiver and would like to use them in the preselector (RF amp) tuned circuits. Anyone with this experience???