[Milsurplus] Screen Bias in ARC-5 Transmitters

[Bill Stewart]

Hey John,
I just got a T-19 going and I am running abt 500-550VDC, key down
on the plates of the 1625s. I am running it on CW only and w/o 
scr/vfo regulation. I used the info from AB5S/W7EKB for the 'conversion'.
They give info on a voltage divider that will give scr and vfo
voltages within spec. Check their info for the recommended p/s specs.
Can't rmbr just where my voltages were, but can check later if you
need the info. My T-19 sounds good (to me) with only a slight chirp
and very stable. I have no experience with the modulators or other 
accessories.
GL and 73 de Bill K4JYS

----- Original Message -----
From: "J. Forster" <jfor at quikus.com>
To: ARC5 at mailman.QTH.net
Cc: Milsurplus at mailman.QTH.net
Sent: Thursday, October 24, 2013 7:59:50 PM
Subject: [Milsurplus] Screen Bias in ARC-5 Transmitters

Hi,

I'm looking for confirmation of the approximate screen and plate voltages
in ARC-5 transmitters and modulators.

>From the simplified Modulator diagram (Fig 4.2) it looks like the plates
of the 1625s are at roughlt 550 VDC.

The screen voltage seems to be roughly the drop across the VR-150-30 
(0D3) VR tube. (Actually, it looks to be about 56 VDC higher, due to the
resistive divider.

So, roughly, does 550 VDC on the plate and 200 VDC on the screen sound
about right?

-John

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