[ARC5] RBB-6 Bring-Up

[Mark K3MSB]

As my other posts have indicated, I've been working on my RBB-6 the past
few days.

Several folks sent me data from their NAVSHIPs 91469 manual (Thank  you)
for table 7-9, and they all agreed with my copy.   Maybe I'm way off base,
but I still say that table is wrong in places, especially for V-308.

If you look at the schematic near the Reception Transfer Switch (S-304),
an annotation to the right of wafer 5 says “All switches viewed from front
of unit”.   The annotation next to wafer 4 indicates that those wafers are
viewed from the rear of the unit!    Rotating clockwise from CW-OL to
MOD-AGC-SIL can only be done if those wafers are viewed from the rear, as
you need to turn CCW to go from CW-OL to MOD-AGC-SIL.

My resistance readings differ in the MOD position.  My CW-OL readings are a
bit different form the manual, but I can account for them (for example,
based upon the actual setting of R-356).

V308 discrepancies in MOD position:

Pin 4:   Manual says 50K.  I get 0.   Rotating  wafer #2 CW two positions
grounds the line from pin 4.

Pin 6:  Manual says 500K.  I get infinite.    Rotating wafer #5 by two
positions ground the line from pin 6.

Pin 8:  Manual says 500K.  I get infinite.    Rotating wafer #5 by two
positions ground the line from pin 8.

Rotating the wafers on the schematic CCW doesn't give the table resistances
either!

Even with some very different resistance readings for V-308 I decided to
power up the unit.

I incrementally (and separately)  fed power to the 200V and 105V circuits.
I used 10V increments from 10 to 50V,  then 50V increments upwards.   I let
each level “cook” for 1 hour while monitoring current draw.   Tubes removed
of course.

At 208V input, to get a 200V deflection on the RBB's front panel DC meter,
current was 18 to 21 mA depending upon the Reception Transfer Switch.

There was virtually no current draw on the 105V circuit (which doesn't feed
much....).

Comments welcome....

73 Mark K3MSB
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