[Milsurplus] Using GDO to check bc-348 coils.

[John Hutchins]

  All -

Thanks for all the advice to get you all up to date where I am at in 
restoring my frist
BC-348R.   Have replaced all the paper bypass caps, all but 6 .01 mica 
by pass caps.
Yes even the sneaky .01uf in the BFO can.  Checked all the RF/OSC micas 
that feed the Tuning cap.
most were on the mark ~< 3% off of posted value.  All caps checked with 
an LCR meter and RVAM for resistors.

So tuned up the old beast using a HP8601A signal generator.

After the tune up these are the symptoms of receiver; Band 6 18-13.5 Mc  
squeaky, wobbly, tuning 13.5 - 14.0 bottom end.  Low ends of 3 bands 
seem to be out of spec.

For each band  wanted to spot what the actual frequency was when setting 
to lowest setting for each band.
Band range      low value found at low mark
1.  500 - 200                                  200.00 khz
2.    3.5 - 1.5                                   1.500 mhz
3.    6.0 - 3.5                                   3.447 mhz   - .984%
4.    9.5 - 6.0                                   6.040 mhz    .011%
5.  13.5 - 9.5                                   9.389 mhz   -.988%
6.  18.0 - 13.5                               13.485 mhz   -.9%
All spotted using  the Frequency counter to monitor the HP8601A signal 
feed to the BC-348R.

I purchased a GDO Millen 90651 tube type, of course! , to see if the 
coils meet published Q at rated frequency. In manual.

So the GDO Millen 90651 is not acting correctly in my opinion.  It goes 
from .15 ma to 1ma consistently no matter which coil is plugged in when 
rolling, tuning,  from low to high frequency.

Since Q = F1 / 2* (F1-F2)
where F2 = 70.7%  of F1

So when the meter is around .15ma it is tough to :
1. Get or find a dip;
2. Find %70.7 / from the dip
just a tad difficult?

Since the coils are all good on the GDO.  A signal is detectable on the 
radio.   I was hoping for a pointer to a AH-HA problem, solution.....


-Hutch