I use this checklist when rebuilding an R-390A. This checklist started from Chuck Rippel's R-390A Owner's Manual, with some details added regarding types of paint, lubricant, cleaners, and polish. This list is a place to record the work completed as you rebuild your R-390A receivers.
Manuf/Contract: : __________________________________________ S/N: _______
The information is shared without warranty, expressed or implied.
N D
E O
E N
D E
| Clean switches and control pots with Caig Laboratories, DeOxit® | ||
| Remove all sub-chassis assemblies and clean main chassis with water displacement/lubricant | ||
| Clean chassis surfaces with Simple Green followed by WD-40 | ||
| Clean away grease from gears with Electric Motor cleaner | ||
| Disassemble, clean, lube, reassemble gear train | ||
| Shine dull metal surfaces with Nevr-Dull | ||
| Lubricate front panel switch click stops with synthetic grease | ||
| Remove all subchassis modular plugs and clean pins. Apply Caig Laboratories, DeOxit® to plug sockets and reinstall | ||
| Install 3 wire A/C cord per military procedure | ||
| Verify proper fuse value(s) | ||
| Add B+ fuses if not installed | ||
| Add CL80 current limiter | ||
| Remove, clean and grease front panel bearing-thrus for "Kilocycle Change," "Megacycle Change," "Bandwidth," "Ant Trim," and "BFO Pitch" controls | ||
| Test all vacuum tubes and replace as required | ||
| Clean all vacuum tubes and apply Caig Laboratories, DeOxit® to pins and reinstall |
Manuf/Contract: __________________________________ S/N: _______
N D
E O
E N
D E
| Remove, sand, repaint, re-white and bake-finish all control knobs | ||
| Remove, clean, strip to bare metal, fill as required, sand, repaint, re-letter and bake-finish front panel | ||
| Remove, sand re-paint and bake-finish readout bezel. Clean lens. | ||
| Replace stainless steel front panel screws | ||
| Remove and refinish meters |
Manuf/Contract: __________________________________ S/N: _______
N D
E O
E N
D E
| Verify production mods, and add any that are missing | ||
| Set cam profiles to match PTO electrical "length." | ||
| Set Veeder-Root counter for proper (35kc) end run out | ||
| Remove all RF and IF slug racks and clean hardened grease from bearing slides (WD 40 on a rag or Q-tip). Flush bearings with 50/50 mix of Mobil synthetic oil and Marvel Mystery Oil (penetrating oil). Apply synthetic grease to slide surfaces. (see Hints and Tips for recommended grease) | ||
| Re-solder connections in signal path with silver-solder, including inside T207 and T208 | ||
| Clean bandswitch contacts with DeOxit | ||
| Clean and lubricate camshafts and detent wheel and veeder root gears with synthetic grease | ||
| Clean Veeder-Root counter readout dial | ||
| Clean sub-chassis | ||
| Clean antenna trimmer and align gear train. Lubricate helical gear (just the metal gears where they contact, not near any shafts!). Flush oil from antenna trimmer bakelite sleeves and washers with flux remover. The trimmer gears are at AGC potential. If audio “pops” on strong signals, this is often a sign that the antenna trimmer bakelite insulators have been coating with oil. Set calibrator frequency | ||
| Replace all paper caps – optional | ||
| Replace C327 with 100 pF NPO ceramic disk – optional, but recommended | ||
| Tighten all tube socket screws |
Manuf/Contract: __________________________________ S/N: _______
N D
E O
E N
D E
| Remove PTO, disassemble, clean and lubricate with synthetic grease. Do not apply where ground spring contacts shaft. Apply DeOxit here. | ||
| General visual check, test for bad connections | ||
| Verify production mods, and add any that are missing (field change 7) | ||
| Reinstall PTO and set end points | ||
| Shim PTO for proper mechanical centering on tuning shaft | ||
| Set "Zero Adjust" clutch for center | ||
| Clean sub-chassis | ||
| Tighten tube socket screws |
Manuf/Contract: __________________________________ S/N: _______
N D
E O
E N
D E
| Verify production mods, and add any that are missing | ||
| Replace C-553 with .01ufd 600V Orange Drop capacitor to protect mechanical filters | ||
| Replace all other paper caps with 400V Sprague Orange Drops | ||
| Replace "Carrier Zero" pot with 10 turn, precision wire-wound variable resistor to allow accurate meter setting (optional) | ||
| Grease "Bandwidth" click stops | ||
| Tighten all wafer switch stacks, and clean with DeOxit | ||
| Clean sub-chassis | ||
| Trim input and output capacitors to mechanical filters if necessary | ||
| Tighten all tube socket screws |
Manuf/Contract: __________________________________ S/N: _______
N D
E O
E N
D E
| Verify production mods, and add any that are missing | ||
| General visual check and test for bad connections | ||
| Clean sub-chassis | ||
| Replace 8uF wet tantalum capacitor with dry tantalum capacitor | ||
| Rebuild C603 and C606 multi-section electrolytic capacitors with new components | ||
| Replace all paper caps | ||
| Check value of R614 (560 ohm), and replace with 2W resistor if replaced | ||
| Tighten all tube socket screws |
Manuf/Contract: __________________________________ S/N: _______
N D
E O
E N
D E
| General visual check, test for bad connections | ||
| Optionally, upgrade to solid state rectifier (3A, 1KV diodes). If done, consider adding 220 ohm 20W resistor in B+ line to limit B+ voltage. | ||
| Clean sub-chassis | ||
| Tighten all tube socket screws |
Prior to final Q.C., each radio is operated for a full 3 hours. This allows the unit to properly heat-saturate before a full alignment of:
 | 1st and 2nd IF's (stagger tuned) |
| Antenna balance |
| RF Sub-chassis assy |
| IF Gain |
| AGC coupling |
| BFO neutralization |
| Crystal filter neutralization |
| Mechanical filter impedance matching (where applicable) |
| 1st Crystal Oscillator |
| Carrier Level meter (will drift with time and is user adjustable) |
| Sensitivity Measurements |
| On-Air Testing |
Last edited 29-Jan-2002