[Milsurplus] Please point in the correct direction

[Al Klase]

I agree with Glen on his GDO points, and you won't have grid current 
when it's not oscillating..

Further:  If that radio still contains the original "Micamold" bypass 
caps, you're probably going to be guilty of trying to tune up junk.  
Recap the thing first.  For most of the caps in that radio, you can just 
cut the exposed leads on the caps, leave them in place and install new 
small devices on the front of the terminal boards.

My two cents,
Al

On 9/26/2010 11:19 PM, Glen Zook wrote:
> As for the grid dip oscillator:  It is pretty common for the meter to read higher as you go higher in frequency.  My Millen does this as do my Heath GD-1A and GD-1B.
>
> Now for aligning your BC-348 the GDO is going to be basically useless.  The frequency calibration of the GDO is horrible at best and there is nothing that even approaches a calibrated attenuator.
>
> Over the years capacitor age, etc.  All that is probably needed is a "touch up" of the variable capacitors and/or a "touch up" of the variable inductors in the oscillator section.  Perfectly normal for an older receiver.  You need a good signal generator with a well calibrated attenuator and some kind of frequency standard.  Of course a "service monitor" is has both a well calibrated attenuator and is a frequency standard.  However, a good "normal" signal generator and a source of known frequencies will allow you to align the receiver correctly.
>
> Glen, K9STH
>
> Website:  http://k9sth.com
>
>
> --- On Sun, 9/26/10, John Hutchins<olegerityincj at austin.rr.com>  wrote:
>
> I know this group is not the place for this question so please redirect me:
> My BC-348R that I have owned since 1971 is a bit sick.  4 of the bands are to low at the low end of the dial.  Not by much but enough to cause concern, that a coil or capacitor or both are in need of repair.
>
> I purchased a James Millen GDO to help, resolve possible problems, check the coils Q at rated frequency.
>
> The GDO 90651 it self has problems ... cant win. Symptoms : as you roll the thumb wheel forward to increase frequency the needle increases from 0 towards 1 ma the reverse is true, the needle falls as the thumb wheel decreases frequency.  Symptom is the same on all bands, plug in coils.
>
> All caps and resistors  are within tolerance of there published values.  Voltages are good.
>
>
>
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-- 
Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/