[Amps] SB220 Filimant Voltages

Pat Barthelow aa6eg at hotmail.com
Wed May 2 12:00:39 EDT 2007

Hi Roller,     (Hmmm do you notice Americans REALLY smile at you when they 
greet you?

I found some photos of the bottom chassis area of the SB 220 on the web:




I cant tell from the photos,  where the 3000 volt AC is routed to the DC 
supply on top. and it may not exist in the bottom of the chassis, but BEWARE 
OF IT!  FIND OUT WHERE IT IS ROUTED and STAY AWAY with your Voltmeter, 
hands, etc..

After checking line voltage directly at the transformer primary leads, I 
(refer to photos )

My guess is there should not be more than a couple tenths of a volt drop 
from the Transformer leads to the Pins of the tube.

1.start at the rear terminals of the filament choke, where you would have 
the highest voltage,

2.then the other end of the filament choke, directly on the choke heavy 
enameled wires,

3.then on the jumpers between the ceramic sockets,

4. then the ceramic socket clips,

5. then directly on the bottom tips of the pins.

KEEP CLEAR OF THE B+, wherever it lurks!

73, DX, de Pat AA6EG aa6eg at hotmail.com;
Skype: Sparky599
Moon or Bust!--Jamesburg Gang Rides Again!

>From: "roller" <roller at comtech-data.se>
>Reply-To: roller <roller at comtech-data.se>
>To: <Amps at contesting.com>
>Subject: [Amps] (no subject)
>Date: Wed, 2 May 2007 17:24:57 +0200
>hello!.. i bought a new digital multimeter to be shure... it is 4.1 volts 
>on the filament.. i will be resoldering everything this evning.

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