[K4RY] K4RY: Kenwood TS-450S repair successful !!

[WB4LNM at aol.com]

Good news for this evening:  
 
The repair on the TS-450S seems to have gone well, and the unit is now up  
and working on all ham bands.  Receive sounds really good, and have not had  
a single unlock episode.  I had one conversation with a friend in B'ham and 
 he said the audio sounded very good.  
 
I could force the unlock signal in the display by tuning the capacitor  
that was replaced (that is as expected), and the synthesizer tuning voltage  is 
now exactly what the service manual says it should be.  It was *much*  less 
when the unit was intermittent.  Seems solid now.  
 
The technical stuff:  The problem was a physically broken variable  
capacitor buried deep down inside the radio.  This capacitor determined the  center 
frequency for the voltage-controlled-oscillator that is part of one of  
three frequency synthesizers in the radio.  How such a small part (less  than 
1/4" on a side) so deeply within the radio would have gotten broken is  a 
puzzle to me.  Anyhow, I had a similar one in the 'junk box' that was a  good 
enough physical and footprint fit.  Should be fine for many, many more  
years.    
 
Into a 50 ohm dummy load with a Drake W-4 wattmeter, I was able to get the  
following power outputs:
 
160      105 watts
 
80        115 watts
 
40        118 watts
 
30        115 watts
 
20        115 watts
 
17        105 watts
 
12        110 watts
 
28        110 watts
 
29.7     105 watts
 
Looks good to go, so I'll probably bring it back to the station in  Broun 
on Thursday prior to the meeting.  I hope everyone will get a  chance to use 
the unit since it will be back on line.
 
73
 
John...
WB4LNM
 
 
 
 
 
       
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.eng.auburn.edu/pipermail/k4ry/attachments/20110301/aecbbdb1/attachment.htm