1R5


Home Up 1R5 501

 

 

 This Packard-Bell model 1R5 is an Electronic Kits training radio.  

This AA5 was part of a student lab used to teach theory and practical assembly skills with this hands on trainer radio.  This radio suffered from what sounded like Silver Mica disease.  It turns out to have been a cracked silver mica capacitor with in the first IF transformer.  It was the last capacitor disk changed. It fell apart when de-soldered.  All the ceramic disk caps in the IF cans have been replaced with Silver Mica capacitors rated at 500 volts.  I suspect these caps will last a life time.  

All out of tolerance resistors were replaced.   The carbon composition resistors usually go high with time and if they are overheated during soldering.  There was also a questionable 0.047 uf cap that also has been replaced.  The original filter caps are still good.  All tubes tested and a full electronic alignment has been performed. I found an identical chassis model number 531 to verify the alignment specs.  The 531 is a production model sold in stores.  I have been listening to "When Radio Was." on 1410 KQV am radio.  Chandu the Magician was the story tonight.  

 

IMG_3833.jpg (105114 bytes) IMG_3834.jpg (138219 bytes) IMG_3836.jpg (122115 bytes) IMG_3832.jpg (167229 bytes) wpe5.gif (76738 bytes)

The rest of this document can be found at

 www.Radiomuseum.org.

IMG_3816.jpg (163671 bytes) IMG_3817.jpg (146302 bytes) IMG_3818.jpg (143035 bytes) IMG_3824.jpg (193774 bytes) IMG_3825.jpg (185971 bytes)
IMG_3827.jpg (117893 bytes)All the disks tested near 59pf.   IMG_3828.jpg (119377 bytes)This cap is chipped.  I suspect this was the source of the crackling.  I simply measured both chips in the cap meter.  The total cap added to  ~95pf.  IMG_3831.jpg (88430 bytes)100pf silver mica caps fit the bill nicely.   IMG_3822.jpg (64018 bytes)  

The IF transforms peaked nicely at 455 kHz.  The top end frequency was set at 1620khz (spec).  The low end receives down to about 490khz.  That is out of the standard broadcast band.  You may hear the occasional air port beacon or boot-leg station below the standard bands.  The dial is a bit off at the lower frequencies.  This seems to be an anomaly of this particular chassis.  I verified the IF frequency to be sure.  A wrong IF can throw off dial scale.  Unfortunately when peaking the 600khz slug in the oscillator coil the lower scale sometimes slides off of the marked dial scale to obtain peak sensitivity.  This is a compromise between low end sensitivity and dial scale accuracy.  Some radios have a compensated dial scale (i.e. not linearly printed).  I see this often.  

This is a rather sensitive little radio.  It picks up the local Disney station on 540khz strongly.  The location of that station is a considerable distance and through a hill from this shop.  Most radios need an external antenna to receive this station. 

Hit Counter

 

 

 Contact me including your thoughts and comments. 

Please see the LINKS page.  I have collected many resources over the years.

135,912 unique web site visitors (14,499,000 hits) from October 2004 through August 2011.

Copyright 2004 - 2012. All rights reserved.