[Central-Electronics] 20A Serial 4544

[AA8K73 GMail]

I would use a low-value resistor to limit charging current to 
the filter capacitors.  Also, a HV fuse to protect the 
transformer secondary from a shorted filter capacitor.

My line voltage is almost 125 VAC now, compared to the 110 VAC 
when this equipment was designed.  Can be a challenge for 
Heathkit equipment with electrolytic capacitors right at the 
voltage limit.

Mike - AA8K


On 2/11/20 11:29 AM, Curt wrote:
> Just received a very nice 20A in the rack mount configuration. 
> Includes the QT-1.   I have never seen a picture of one of these 
> before and wonder if they all came with rack handles?
> 
> Also, on receiving inspection, I see potting pitch around the 
> bottom of TR-1.  It is a bead about 3/16 dia around 1/2 of the 
> diameter of the can.  Is this a common thing or should I plan on 
> finding a replacement?
> 
> What is the consensus on changing to SS rectifier  and resistor  
> to replace the 5U4?  I like reducing the load on the transformer 
> and the exposure of the HV to the filament winding.   Are theses 
> transformers a problem area like the ones in the old 
> Hallicrafters HT-37s?
> 
> Thanks.  I look forward to putting this 20A on the air.
> 
> Curt,  KU8L