[Boatanchors] Why connect the heater to the cathode?

[Philip (KO6BB)]

Hi,
I haven't looked at the exact circuit. But this was rather common in 
circuits where the Voltage on the cathode is quite high and 
possibly/probably exceeding the cathode/heater insulation rating. Those 
circuits typically also run the heater of any tubes with high Voltage on 
the heater from a separate winding on the power transformer for the same 
reason.

73 de Phil, KO6BB
http://ko6bb1.multiply.com/ (My OTR Blog)
http://www.qsl.net/ko6bb/ (Web Page)

RADIOS:
Yaesu FT-2000 Xceiver for "hamming" and LF Beacons.
National NC-183 16 Tube General Coverage.
Zenith "American" Royal-7000 Transoceanic Portable.
Zenith "Taiwan made" 7000-2 Transoceanic Portable.
Radio Shack DX-380 digital portable.
6 Hz Audio filter, Tunable LF Pre-amp for NDBs.

ANTENNAS: 88' Long balanced dipole.
"Mini-Whip" (active antenna) for LF.

Merced, Central California, 37.3N 120.48W CM97sh


LeeCraner at aol.com wrote:
> In the 1959 handbook is a electronic voltage regulating circuit (the same  
> circuit can be seen by pulling up the RCA 5651 tube data sheet off of the  
> Web).  The circuit uses a 5651, 6AS7 and a 6SL7.  
>  
> What I find interesting is that the 6SL7 heater is connected to the  
> cathode.  What would this accomplish?
>  
> 73
> Lee WB6SSW
> ___