R-388 s/n 182

Summer, 2009

    This receiver has an excellent front panel, both top and bottom covers, with the wing nuts for the top cover.  Only slight marking at the rack mount holes.  The KC dial is nice, no holes or scratches.  The MC band drum is somewhat yellowed, not badly, some stains and a few small marks.  Inside, dusty as received, no alignment tools, but has tube/filter and xtal hold-downs.  The top cover has the original Allen & Bristol wrenches in their clips.  All tube shields present.  Has Navy anchor logo on outsides of side panels & on top front bracket. Slight pitting on outside of side panels.  Has all knobs, original and shiny except some scratches on the RF gain knob.  IF cans are shiny, but have ID scratched into the top of each. 

    When powered up it received good signals on the AMBC band, but not strong audio.  Did receive on all bands.  The PTO is off ~11kc from end to end. 

    After removal of the bottom cover it was found to be clean, and no indication of modifications or previous work.

    Tubes, knobs and MC drum were removed and chassis was cleaned.

(no pix of "before" condition)

pnlb4PD.jpg (817688 bytes)         pnlaftPD.jpg (979553 bytes)                        pnlaftPD01.jpg (913939 bytes)   pnlaftPD02.jpg (826947 bytes)

back of panel before & after (black) product detector cables added.  I re-installed the panel, tested all tubes  (replaced a 12AX7) & got the dials lined up (preliminarily) after putting power on it.  Could hear signals on AM, but no BFO connected due to the cabling changes being started. 

   The PTO has been pulled & refurbed, incl. trimming the compensating coil to change the "span", which was 11kc end to end.  After recalibration it's now ~ 1/2kc end to end & better than that between each 100kc point. 

underB402.jpg (917345 bytes) underB403.jpg (1040948 bytes)underB401.jpg (1154263 bytes) 

Underneath pix before removal of bathtub capacitors & any product detector wiring installation.  Solder has been "sucked" from bathtub capacitor terminals.

.socstrip.jpg (1154982 bytes) 

sockets stripped for product detector installation & C-204 replacement.  IF input filter for the prod. det. is installed, just above the "Orange Drop".   The BFO tube gets changed from a 6BA6 to a 6BE6, with major wiring changes on the socket

bathtubrepl01.jpg (1021468 bytes)                                                                  botoa.jpg (1312896 bytes)

One bathtub capacitor replacement                      bottom view after all caps replaced & most under-chassis work done.

ProdDet.jpg (1221515 bytes)                                                 frt01.jpg (1171377 bytes)   top01.jpg (1082829 bytes)

Product Detector area, completed                         front & top views during alignment

Completed --

topviewcov1.jpg (516481 bytes)  topviewcov2.jpg (642736 bytes)  topviewcov3.jpg (469557 bytes)   botviewcov.jpg (638995 bytes) frtview1.jpg (841854 bytes) topcovIns.jpg (856823 bytes)

                            outside views with covers                                                                      inside of top cover

topview1.jpg (805414 bytes) topview2.jpg (796396 bytes) topview3.jpg (547572 bytes) 

                    top details

botview.jpg (1096729 bytes)      AVCmod.jpg (913884 bytes)                 ACinput.jpg (819515 bytes)         ProdDet2.jpg (916501 bytes)              R388PD_AVC.jpg (1215751 bytes)   

inside details       AVC mods. term. strip            AC line cord input       Prod. Det./BFO  area       Prod. Det. & AVC schem.

 

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