[ARC5] BC-453 B dynamotor hum

[Kenneth G. Gordon]

On 3 Nov 2015 at 15:42, J Mcvey via ARC5 wrote:

> The output from the dyno is approx 187 HZ and looks somewhat like a half wave
> rectified sine wave with the flat part on top.LV DC is clean except for about
> 400 mv of hash from the dyno with random very fast rise time spikes of about 1.5
> volts. I cleaned and lubed the bearings a while ago but didn't clean the
> commutators, they looked OK- but obviously not the case.How does one go about
> cleaning them?

Well, at this point, I would guess that you have a bad dyno. Perhaps a bad 
winding, shorted or open. Maybe shorted. Can you try another?

Ken W7EKB