Re: Working with vaccum tubes

---------

From: George, W5YR (w5yr@att.net)
Date: Mon Oct 22 2001 - 15:52:46 CDT


RE final amp tanks, remember that one can replace the series feed that puts
HVDC on the stator with parallel feed that prevents it. I cannot recall
ever building a tank circuit that didn't use parallel feed. Not only does
it remove the shock hazard that Jim addresses but it allows the voltage
rating of the capacitor to handle a much higher r-f level.

Sure seems funny to be posting this to QRP-L! <:}

72/73, George W5YR - the Yellow Rose of Texas QRP-L 1373 NETXQRP 6
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe SOC 262
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
Icom IC-756PRO #02121 Kachina #91900556 IC-765 #02437

Jim Stamper wrote:

> Speaking of 12 or 15 volts, the stator plates of the final amplifier's
> "tank" capacitor in tube rigs often was hot with whatever DC you were
> applying. The rotor was usually grounded. When you were going to be
> working inside a rig it was always a good idea to close the rotor so none of
> the blades would get bent. It was also good practice to disconnect the
> power supply. Once I forgot with 600 volts DC on the stator when I pushed
> the rotor closed. I didn't realize I was "connected" until I smelled my
> finger burning.


Search QRP-L Archives

[ QRP-L Archive | ]
[ 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 ]

---------

This archive was generated by hypermail 2b29 on Fri Nov 09 2001 - 15:06:01 CST

kd4ab@kd4ab.org