[ARC5] BC-454-B Dymamotor Question Part 2

[WA5CAB at cs.com]

If you can hear that in the audio output, it must be being coupled into the 
12A6 grid circuit through a blocking capacitor somewhere.

Robert D.

In a message dated 01/31/2013 22:55:49 PM Central Standard Time, 
jfor at quikus.com writes: 
> If you are seeing <50 mV on 250 VDC, you are doing fine, IMO.
> 
> -John
> 
> ==============
> 
> 
> Gang –
> >
> >
> >
> >Well, I think it's been around a week and a half since I lasted posted on
> >my "saga",  but I did find some time on Saturday to rebuild my DM-32A for
> >my T-19.  I lubricated as per the manual and the work went OK.
> >
> >
> >
> >Tonight I took some measurements.   There's still "hum" on the audio, but
> >I
> >think it's a bit better.  Here’s some pictures of the new waveforms.
> >These
> >were taken by using a voltage divider (10K, 100K) into my scope,   and
> >taping off the socket upon which the dynamotor sits in the radio.
> >
> >
> >
> >Picture 2858:
> >
> >www.k3msb.com/temp/100_2858.jpg
> >
> >
> >
> >40 mV P-P (scope at 20 mV / division)
> >
> >Period of 9 mS (scope at 5 mS / division) which is 111.1 Hz.
> >
> >Input voltage is 2.2 VDC from the divider, or 24.4  VDC into the radio.
> >

Robert & Susan Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480