[Heath] SB200 HV Question

[George Collins]

Hi Jim,

 

My SB200 HV runs higher than that.  More like 2400V idling, as I recall.  I
wouldn't expect the caps to cause a low idling voltage.  I would check the
resistors in the HV metering circuit first.  I have replaced mine with
metal-film resistors, paying attention to the voltage rating of the new
resistors.  I used more resistors in the string to get the voltage across
each resistor below the maximum voltage rating of the individual resistor.
Of course the maximum wattage rating of the resistors must be met too.  The
old resistors had changed value over the years.  The voltage rating of some
resistors can be as low as 300V.  It's often overlooked that resistors have
a maximum voltage along with the maximum wattage rating.

  

73,

 

George, KC1V

 

 

 

From: Heath [mailto:heath-bounces at puck.nether.net] On Behalf Of Jim's
Sent: Thursday, February 02, 2017 8:51 PM
To: heath at puck.nether.net
Subject: [Heath] SB200 HV Question

 

I have finally got my SB200 on the air. The cap's have been replaced many
years ago but everything else is stock. My idling HV runs about 1900v's key
down it drops to about 1750V's. Line voltage to the amp is off a separate
120 v 20amp ckt. Is this voltage normal? Should I be looking for about
2500v'idiling? Would changing the caps to 180mfd and changing the equalizing
resistors to a lower value help? 

 

Thanks for your information 

73 

Jim K8DHC

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