[Heath] SB200 HV Question

[Jim's]

Thanks for the suggestions, I have measured the HV with a HV probe and a
digital meter. It does agree with the panel meter on the amp. I'm leaning to
soft cap's since they were replaced 10yrs or more ago. Probably they have
some internal leakage resistance. When operating on 80 & 40M's plate current
is about 350-400ma, as mentioned earlier, HV is about 1800 drops to 1750.
I'm driving it with 60w's,on an SB610 scope there appears about a 4X output
display from exciter and amp output.. I don't feel line voltage would create
that much of a lower HV. All other devices in shack are operation fine. Line
voltage is running about 122ac.  

 

Jim K8DHC

From: Heath [mailto:heath-bounces at puck.nether.net] On Behalf Of Guy
Giacopuzzi
Sent: Friday, February 03, 2017 8:30 PM
To: heath at puck.nether.net
Subject: Re: [Heath] SB200 HV Question

 

Mine's 2850 vdc idling...drops about 100 or less key down...

Guy,

WA6OQQ

 

On 2/3/2017 4:54 AM, Ken, W8EK wrote:


Resistors for high voltage metering For Sale: 

Do you have a Heath linear amplifier that has an 
error in the high voltage reading? Maybe you do 
not even know it has an error! 

Heath used three 4.7 meg resistors in the SB-220/221 
and also in the SB-200/201 amplifiers. Almost all 
of these resistors are out of tolerance today, partially 
because of their age, but also because their voltage 
rating was exceeded. 

I was able to obtain a quantity of new resistors that 
are 4.7 Meg, 1% tolerance, 2 watt, and are rated to 
handle the high voltage. This compares to the original 
resistors furnished by Heath that were 4.7 Meg, 5%, 
1 watt and about 400 volts. 

Buy a set of three for $3 plus shipping from Florida. 
Combine with other items to save shipping! 

Thanks. 

73, 

Ken, W8EK 

Ken Simpson 
E-mail to W8EK at FLHam.net or W8EK at arrl.net 
Voice Phone  (352) 732-8400 



Paul Blumhardt wrote on 2/2/2017 9:07 PM: 



Jim 

                Your HV meter reading is likely low due to the voltage 
divider resistor string going up in value. Check those resistors 
before doing anything. 



                How much power output do you see on 40 meters? Output 
power is the real test of if your amp has a problem or not. 



Vy 73 

Paul 



*From:* Heath [mailto:heath-bounces at puck.nether.net] *On Behalf Of *Jim's 
*Sent:* Thursday, February 02, 2017 7:51 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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https://puck.nether.net/mailman/listinfo/heath 

 

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