Crosley DU-17 TOL1
   

17" screen, 1951

click on image to enlarge



This is actually a table model with matching stand.  The hinged access door doubles as a dial scale for the continuous tuner.  This set is equipped with jacks for a color converter, but it is likely that broadcasts using the CBS color standard had already been halted before it was even sold.


Tube Complement
RF amplifier   1   6CB6
mixer/oscillator 1 12AT7 
video IF amplifier  3   6AU6 
4th video IF amp 1   6CB6
video detector/noise limiter 1   6AL5
video amplifier  1   6CB6
DC restorer/sync takeoff 1    6C4
AGC amplifier 1   6AU6
sync clipper/sync output 1   6SL7GT
horizontal oscillator/AFC 1   6SN7GT
horizontal output 1   6CD6G
damper  1    6W4GT
vertical oscillator/output 1   6BL7GTA
audio driver  1   6AU6
audio detector 1   6AL5
audio amp/AGC delay 1   6AV6
audio output 1    6W6GT
B+ rectifier 1    5U4G
HV rectifier 1     1B3GT


I broke a long TV restoration sabbatical with this project.  Soft-starting with the horizontal tubes removed produced encouraging results, with reception and audio coming in around 70 volts--but a light show in the 5U4 beginning around 90 volts.  The CRT literally tested like new on my Sencore tester, proving it worked--the tester that is.  I had thought there must be something wrong with it because it flunked every one of the tubes I first tried on it.  I later learned the old addage of good things coming to those who wait applies especially to the testing of picture tubes which haven't had power applied in many years.

So with all the major organs confirmed healthy, I pulled the chassis out of the cabinet.  Tipping it up for the first look underneath revealed it had been repurposed...



...as a lovely home.  Miraculously, the tenant used material from outside the home exclusively as nothing underneath had been chewed.  With all the twigs and itchy fiberglass removed I went to work replacing all the electrolytic and paper capacitors, of which there were many, some in values I had never encountered before.  Fortunately Just Radios in Canada carries virtually every value cap encountered in vintage gear. 

This set, to a degree far exceeding any TV I had worked on before, showed marked improvement with every stage of recap progress, going from snowy and unstable to clearer but still wobbly to finally rock solid when new electrolytic caps arrived in the mail and I was able to replace the last three of the old ones.

To be fair, a major reason for the snowy picture early on was use of a balun transformer.  Though not explicitly stated in the set's service information, it finally dawned on me that the inductuner has a 75 ohm input and needs to be connected directly to the coax.



The TV appears to have served faithfully for many years with few repairs needed aside from the occasional tube replacement.   However, there is convincing evidence that the set was serviced at one time or another by two very different shops.  One shop replaced the original electrostatic-focus tube with a 17BP4 and did a magnificent job adapting the set to use a magnetic-focus tube.  It's hard to believe the same shop did such a sloppy job on the mere replacement of an electrolytic cap complete with loosely-wrapped lead and cold solder joint.

 

 

 

 


From this...

...to this

Not every restoration project can be finished just with new capacitors and some tube swapping and no set can work better than it was designed to.  But the outcome of breathing new life into this terrific set serves as an example of just how rewarding the vintage TV restoration hobby can be.



©2011-2016 Phoenix Enterprises