[Heath] [Heathkit] SB-401 / HV drop upon keying

[howard holden]

Hi Rob,

Some drop is to be expected. The 60v you show is about right. That drop is mainly in the resistance of the HV winding. The only way to avoid the drop would be with a regulated supply (not very practical at 800v for our purposes), or to use a supply which can put out way more current than the 6146 finals would draw at resonant full load. 

Good luck with the 401.

73 Howie WB2AWQ

Sent from my iPhone

On Jan 27, 2015, at 8:25 PM, "Robert Myers" <rsmyers at rogers.com> wrote:

> When I key my SB-401 into a 50 Ohm load, and having tuned things up for max
> power, the I see HV drops to around 740 VDC.  Is that normal?  What have
> other measured?  Should it stay at 800 VDC?
> 
> Thanks,
> -- Rob, VE3JQL
> 
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