[R-390] Pearls v 2.0

[wli]

I have gone thru *Pearls*, and reformatted it for easier on-line reading. Also added are some new chapters. Merged the URM stuff into *test_gear*. Found and re-filed mis-filed posts. Most, but not all entries are in chronological order. Sometime ago it was suggested that Pearls needs to be condensed... however, as this collection gets updated every 3-4 months, any condensation will be soon become out-of-date. In any case, its factual knowledge will re-appear in Rev 4 of the Y2K manual. My feeling is that by preserving the headers and the actual language employed in the various posts adds colour to this collection of documents. This is quite a varied group, and it would be shame to lose that aspect. 

This revised version *Pearls* is now up thanks to Al Tirevold.

Current versions of Acrobat Reader do contain a search function, which allows finding specific phrases or topics within any pdf chapter. It is simply too time-consuming to search for subjects manually. My suggestion is that only this index be incorporated into Rev 4.... it adds just a single page of what is already a large document. 

One new addition: an index list of topics within each *Pearls* chapter to give you an idea of how I categorized things. Any faults or errors in judgement, inclusion, or exclusion are mine, and mine alone.

W. Li
Mercer Island, WA
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AC and LINE TOPICS
safety issues
AC grounds
house wiring
power line noise
GFI outlets and the R390A
ground loops

ANTENNAS
UNBAL vs BAL input connections to the 390A
modifications to UNBAL jack
specific book and article references
optimal SWL antenna opinions
types such as T2FD, beverage, whip, long-wire, etc
the active antenna
Fort Deven's Training Manual tips
wire and feedline options
computer RFI
role of antenna tuners
antenna relay and its repair
break-in issues
multicouplers and diversity reception
gorunding the tower and safety issues
physics of ground rods
lightning strikes and sequelae
CAD welding
 
AUDIO DECK
diode load usage and connections
squelch circuitry
limiter circuitry and problems
refurbishing the audio deck module
tantalum C609 electrolytic replacement
the 6AQ5 output
the Kleronomos 6922/6360 circuit
600 to 8 ohm transformers
use of a 70.7 volt line transformer
LS-166 and other speaker options

BALLAST TUBE
rationale for its use
physics behind 3TF7 and its cousins
substitues for the 3FTF7
replacement SS circuits 

CAPACITORS
important caps to replace first
problem capacitors in the R390A
Vitamin Q caps
Orange drop caps: pros and cons
minimal vs wholesale replacement practices
how to test a paper capacitor for leakage
polyester vs polypropylene
molded mica, silver mica, and ceramic cap experiences
C275 mis-value
cap removal and replacement practical tips

DEAD UNITS
common causes
work sequences

HISTORY
active duty experiences
Ft Devens R390 classes
serial numbers
SWL targets
EAC and Fowler units
depot *dawgs*
MWO's
R-648
R-1247 
Racal RA 17

IF DECK
noise
stuck IF slug
coax shorts
trimmer repair
AGC theory and repair
Rippel on alignment
stagger-tuned IF strip
Q-spoiling resistors
Z-503 repair
E20-E211 test points
bandwidth switch repair
BFO microdial
BFO neutralization
Xtal deck issues
R-725 decks
R-390 deck conversion to 390A chassis
synchronous AM detector
DSP IF

IF DECK FILTERS
alignment of the mechanical filters
testing a mechanical filter
rebuilding a mechanical filter
Clevite ceramic filters
Dave Curry filters
question of a notch filter
trim capacitors

MODS AND FC'S
Production mods
misc users modifications

PAINTING AND KNOBS
chassis disassembly
metal prep
cleaning chemicals
silk-screening and engraving
paint options and formulae
Bristol wrenches 
alodine
powder coating
ID plates

PANADAPTORS
Heath SB-620
BC-1031A

PANEL METERS
specifications
calibration
disassembly
repair
substitutes
carrier pot
radioactivity
back-light 

PTO
mnaufacturers
lubrication
adjusting end-points
adjusting linearity
mechanical alignment
setting over-travel
Oldham coupler alignment
coil modification
failure modes
rebuilding
effects of FC 7
dessicants
Conversion of 390A PTO to a 390
R392 PTO
R388 PTO
R389 PTO

PWR SUPPLY_SWITCH
F101 line filter
solid state rectifiers
inrush current considerations
CR801 selenium rectifier
microswitch repair
rebuilding C603/6
C603/6 replacements
ovens
fuse holders
use of STDBY
low heater voltages
use of bucking transformers and Variacs
R390/URR voltage regulator
fuses
12BW4 as substitute for 26Z5
physics behind the OA2 

RACKS AND CASES
sources
rails
nuts

RESISTORS
carbon vs metal film in the 390A
failure modes
pot cleaning

RESTORATION_GENERAL
buying a R390A
overhaul tips
a hamfest shopping list
reference and parts resources
manufacturers listing
specialty R390A models
the *Blue-Striper*
restoration sequence
restoration techniques
special tools needed
dial lamps: OEM and LED
manual listing
expert restoration resources
mini-BNC connectors and coax
contact cleaners
how to clean chassis and coils
soldering
hardware employed
module swaps
cabinets
clutch and the zero adjust
tube extenders
rack mounting
solid-state the R390A
crystal ovens

RF DECK_ELECTRICAL
deck testing: noise and gain
HR-202 issues
S206 bandswitch tips
sync the bandswitch
ant trimmer tips
RF deck slugs and coil problems
100KC calibrator function
missing components C-252
using the Xtal calibrator
dead below 8MC
low Xtal osc output
the Green Gear
effects of FC 7
break-in function
reception below 500KC
digital frequency readouts
R391 and autotunes
Nuvistaplug possiblities
fuction of C227
17MC Xtals
roofing filters

RF DECK_MECHANICAL
cleaning the RF deck and gear train
band switch 
how to remove this deck
gear train
gear clamp repairs
stuck RF slug
busted RF slug
RF slug coding
lubrication
the Oldham coupler
the Green Gear in R390's
zero adjust
autotune in R390's
Veeder-Root 

SENSITIVITY_ALIGNMENT
tutorials
"octave" tuning methodology
Rippel on alignment articles
sensitivity measurements
preselectors
MDS measurements
SINPO explained
sweep gen alignment
aligning the BAL input
generator leakage 
using the GR1001A

SSB CONVERSION
Capt Lee article using a 6BE6
Lankford diode method
CV-157 and CV-591A
other outboard add-ones
6U8 addition
Sherwood SE-3

STORAGE_SHIPPING
packing heavy gear
commercial carriers
horror stories
storing stuff at home

TEST GEAR
scopes and their probes
TS 505 and its relatives
Simpson 260's
HP-410 family
DMM's
HP 600 and 8600 family
repairing moving vanes in meters
URM-25D and URM-25F and others
testing Xtals with sig gens
meggers
tube testers
impedance matching
capacitor *analyzer*
spectrum analyzers

TUBES
characteristics 
equivalent substitutes
gas and Zippo
IERC shields
in situ performance tests
cleaning a tube socket
tube organizing
gettering old tubes

TUBE SHIELDS AND HEATING
IERC shields and heat issues
effect of cabinets on heat buildup
fans
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