[ARC5] RBB-6 Bring-Up

[Kenneth G. Gordon]

Comments:

1) The RBB/RBC have possibly the best output limiter I have ever used.

2) MANY military manuals include significant errors, so don't be surprised when you find 
them. For instance the schematic for the TCM-2 transmitter shows a MAJOR error in the 
wiring to the final amp stage. I corrected that in my own manuals and have posted that 
correction on my website here:

http://www.w7ekb.com/Personal/TCM-2/

3) I consider the RBB/RBC receivers to be the absolute best of their era.

Ken W7EKB


On 16 Mar 2019 at 11:25, Mark K3MSB wrote:

> 
> 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
> 
> 
>