vfo-230 fine tune mod correction
 a note published in your t/k newsletter of january, 1983, issue no. 30, 
concerning a fine tuning mod for the vfo-230, impelledme to purchase a 
new vfo-230 for the sole purpose of obtaining a slower dial tuning rate 
for my ts-380s.  then the combination of a defective new vfo-230 and some 
bad information in your newsletter note triggered many, many hours of 
frustration and irritation over a period of several months starting in june 
1986.  i believe you should know about it when information in your newsletter 
causes frustration and irritation.
 i decided to try the diode cutting bit again.  it did not work.  
the optical dial encoder went crazy.  i was ready to explode and did.  
Fortunately there was nobody around to hear me.  back to the drawing board.  
now i know practically nothing about optical encoders but i do have an 
engineering background so i spent some time staring at the vfo-230 
schematic in the ts-830s service manual.  suddenly the light came on.  
ka0nnf gave you the wrong information about which diodes to cut.  
(his call is not wa0nnf as given in your newsletter note.  i tracked him 
down by telephone.  he told me he had sold the vfo-230 and couldn't remember.)
the proper diodes to cut for 6-1/4 khz per dial rev. are d19. d20, d22, d23, 
d24, and d26.  i presume cutting diodes d19, d21, d22, d23, d25, and d26 
would also work but i will leave that for someone else to try.  in other 
words, of the eight diodes, cut all but d21 and d25 or d20 and d24 fpr 
6/14 khz per dial revolution.
that7s the end of the story.  my vfo-230 now works perfectly at 6-1/4 khz 
per dial revolution.  this jpermits me to use the excellent ts-830s receiver 
on 160m cw with very extreme if (250 hz) and external audio (50 hz) 
seletivity.  incidentally, i wonder how many repair facilities (including 
yours) are equipped to motor drive the vfo-230 dial shaft at 300 rpm while 
observing the optical encoder waveform? this alignment procedure is necessary, 
and is prescribed in the service manual, before you should expect the 
encoder to work at slower than the "stock" rate.  (i think this was part 
of the problem).  

by:  dave.......relayed   by..n0kgx...gene