[hpsdr] LPU Capacity

[Chris Day]

Thanks, Erich. Replacing the soft fuses with wire has been enough so far, but I haven't fired up the transmitter section of Pennylane yet. Linear chain will be external, so there will be no extra load from that. Meanwhile, playing with Mercury with delightful results. Chris DayAE6VK
 > Date: Wed, 28 Dec 2011 04:12:10 -0800
> From: vk5hse at yahoo.com
> To: hpsdr at lists.openhpsdr.org
> Subject: Re: [hpsdr] LPU Capacity
> 
> ***** High Performance Software Defined Radio Discussion List *****
> 
> Have cobbled together various reflector postings for my own reference as well as for others.
> 
> 
> There was a summary posted to the reflector that is worth reviewing:
> 
> http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/2011-March/014678.html
> 
> the meaty bits were:
> 
> Magister = Ozy
> 
> 
> power consumption summary:
> 
> 
>                        12 V         5 v
> OZY               .001  A        .1 A
> PENY             .4 A           .2 A
> MERC            .2  A          .5 A
> 
> Metis 100                         .4A
> 
> Metis 1000bT                   .75A
> 
> 
> no-one seems to have stated excalibur power requirements, but it doesn't appear to be huge
> 
> 
> add the LPU errata document:
> 
> http://www.tapr.org/pdf/LPU_Errata.pdf
> 
> which mentions in errata #2:
> 
> "Description of Error:
> Fuses F2 and F3 are underrated for a full system. They are rated at continuous 1.1A without
> tripping, while an Ozy/Mercury/Penelope system draws typically 1.3A from the +5V rail.
> 
> 
> Symptoms:
> An Ozy/Mercury/Penelope system will operate for a short period and then unexpectedly shut
> down. The time can vary, but is typically around 10 minutes. This is due to F2 opening and shutting
> down the +5V output. (Note that F2 doesn’t actually “open”; it becomes higher resistance to protect
> the load.) After a power cycle, normal operation resumes.
> 
> 
> Recommended Corrective Action:
> Short across F2 and F3 with pieces of wire."
> 
> 
> 
> There has also been talk of strapping the 12V feedtrhough for high power things like a PA
> 
> http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/2010-July/012616.html
> 
> and some suggestion of shorting the 5V fuse and relying on the regulator to protect itself +/- modifying R6 the series resistor
> 
> http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/2010-July/012617.html
> _______________________________________________
> HPSDR Discussion List
> To post msg: hpsdr at openhpsdr.org
> Subscription help: http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org
> HPSDR web page: http://openhpsdr.org
> Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/
 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/attachments/20111228/37c5aa43/attachment-0004.htm>