[AMRadio] 4H4 Ballast

Bob Maser bmaser at tampabay.rr.com
Sun Feb 19 22:52:04 EST 2006

It appears that I have found the problem in my HRO60.  I turned it on one 
day last week and all I could hear was floor noise.  I couldn't even hear 
the xtal calibrator and all drawers(bands) were the same.  After much poking 
and prodding and tube testing, come to find out the 4H4 has a broken 
filament wire, which means that the HF oscillator and the mixer aren't 
getting any filament volts.  Now I need a replacement 4H4.  Anyone have a 
spare they would be willing to part with?  I have a 7H4B but when I plugged 
it in I get 12VAC out to the mixer and HF osc filaments.  My HF Oscillator 
tube 6C4 is really weak so I need one of them too.

Help would be appreciated.

Bob  W6TR  Florida 

More information about the AMRadio mailing list

This page last updated 16 Dec 2017.