>>>> "Chuck" == Chuck Guzis
<cclist at sydex.com> writes: 
 Chuck> On 29 Aug 2008 at 15:12, Paul Koning wrote:
 > I've used 12 volt ("car radio")
tubes in a shortware broadcast
> receiver.  Worked fine as far as I remember. 
 Chuck> Were these the special "space charge" tubes?  e.g. 12J8, 12U7,
 Chuck> 12DK7, 12DL8, 12CX6, 12DE8, 12CN5, 12BL6, 12DS7, 12AC6, 12AD6,
 Chuck> 12AE6, 12AE7, 12AF6, 12AJ6 or 12AL8 (I've probably left out a
 Chuck> few)?
I don't recognize the term "space charge".  They were tubes explicitly
specified in the data sheet for operation with 12 volt anode voltage.
Almost certainly they were Philips -- EFnn and ECHnn for suitable
integer nn...  (I did that project in Holland.)
        paul