[Boatanchors] A National NC-300 answer

[Philip Atchley]

Hi,

If somebody on this list is also a member of the National list, I'd 
appreciate them reposting it to that reflector as I am no longer 
subscribed.

Quite a few months back I was working on a National NC-300 for a friend. 
It had a "dead" first oscillator section.  I spent many days (over a 
period of some weeks) banging my head up against the wall trying to find 
the problem and tapped the best minds on this and the National 
reflector.  Really dug into it and replaced the capacitors in the 
Oscillator section, checked tube socket continuity, replaced tubes, 
checked each switch contact etc.  REALLY went through it with no "joy". 
All coils etc checked good for continuity.

The present owner got it from another gentleman here in California who 
had also spent much time and heartache before finally giving up on it. 
It hadn't worked when HE got it.

Interestingly enough, I received an Email from a gentleman who some 
years before had the exact same problem, finally gave up and sold it to 
somebody in California.  I wouldn't be at all surprised if it were the 
same set!

FINALLY, I gave up in frustration and gave it back to the owner 
unrepaired.  At this point his intent was to put it in the "Club 
Auction" as a "parts" set.

Anyway, an old timer in the Turlock Radio Club asked him to bring it 
over as he once owned a shop that was the Warranty Repair station for 
National along with a few other brands.

Apparently it threw him for a loop for some time too.  Then while doing 
a close "point by point" examination he discovered that somebody had 
repositioned a bare connecting coil wire that passes close to a coil 
terminal lug to where it actually connected to the lug. It may be noted 
here that an OHM-METER check would NOT disclose such a short due to the 
low resistance of all the coils etc.  Probably only somebody that was 
thoroughly familiar with what that compartment was supposed to look like 
would even have a remote chance of finding it!  It was a "solid" 
contact, not an intermittent or anything.

Don (W6LRG) says that is one nice and hot performing receiver now!

73 de Phil,  KO6BB
982 Different NDB's heard to date.

http://users.mercednet.com/beaconeer/
Merced, Central California, 37.3N  120.48W  CM97sh