[hpsdr] Penelope T2 orientation - additional info

[Bruce Beford]

> -----Original Message-----
> From: Graham / KE9H [mailto:KE9H at austin.rr.com] 
> Sent: Saturday, November 14, 2009 11:42 AM
> To: n3evl
> Cc: Bruce Beford; hpsdr at lists.openhpsdr.org
> Subject: Re: [hpsdr] Penelope T2 orientation - additional info
> 
> 
> For TAPR manufactured Penelope boards...
> 
> After the rework.
> 
> The dot on the transformer should be diagonally OPPOSITE the 
> dot on the PCB silkscreen. (The silkscreen dot position is in error.)
> 
> In other words, when viewing the Penelope board, Atlas 
> connector down, and BNC connector to the right, the dot on 
> the silkscreen is lower right, and the orientation of the dot 
> on the transformer should be upper left.
> 
> The transformer should be operating as a voltage step-up transformer.
> 
> --- Graham
> 


Then this is OPPOSITE from the published schematics for Penelope, and means
that T2 does not present a 75 ohm impedance to U2 when it is feeding a 50
ohm load. Based on David Poole's analysis of the power handling capablity
for U6, this has ramifications for the maximum load tolerance of Penelope.

Bruce N1RX



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