[Amps] 8877 Grid Connection DC or Not

[Radio WC6W]

Hi Jim,
    Ah... the unknown factor.

    You could include an (optically?) isolated plate current sensor and then do the math and metering at low voltage.

73 & Good morning,
    Marv WC6W

http://qsl.net/wc6w/



--------------------------------------------
On Tue, 11/29/16, Jim W7RY <jimw7ry at gmail.com> wrote:

 Subject: Re: [Amps] 8877 Grid Connection DC or Not
 To: "Radio WC6W" <wc6w_amps at yahoo.com>, "AMPS" <amps at contesting.com>
 Date: Tuesday, November 29, 2016, 3:37 PM
 
 Marv... Because this will
 be a single power supply and multiple RF deck (5 
 or 6 of them) amplifier system for a contest
 station.  I don’t want to use 
 vacuum
 relays as high voltage switches.
 
 Metering plate current is easy. Simply put the
 plate current meter (set back 
 from the
 front panel for safety) in series with the HV on the RF
 deck.
 
 That’s why.
 
 Thanks
 73
 Jim W7RY
 
 
 -----Original Message----- 
 From: Radio WC6W
 Sent: Tuesday,
 November 29, 2016 11:35 AM
 To: Jim W7RY ;
 AMPS
 Subject: Re: [Amps] 8877 Grid
 Connection DC or Not
 
 
 Hi Jim,
    Why not
 leave the grid grounded but, just measure the cathode and
 plate 
 currents then subtract to calculate
 the grid current?
 
 73 &
 Good morning,
    Marv WC6W
 
 http://qsl.net/wc6w/
 
 --------------------------------------------
 On Mon, 11/28/16, Jim W7RY <jimw7ry at gmail.com>
 wrote:
 
 Subject: [Amps] 8877
 Grid Connection DC or Not
 To:
 "AMPS" <amps at contesting.com>
 Date: Monday, November 28, 2016, 7:00 PM
 
 Has anyone run the grid of an
 8877
 not connected to ground as far as DC is
 concerned?
 
 I really need to
 meter the grid current by bypassing the
 grid
 to ground with capacitors and several 10 ohm resistors
 in order to meter grid current. Metering grid
 current by the
 CT of the filament
 transformer, and the – of the power
 supply
 cant be done. Because the power supply – is
 directly grounded.
 
 Anyone had luck doing this?
 
 Thanks 73
 Jim W7RY
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