[Milsurplus] AN/GRC - 9 Power supply question

[Roger Basford]

Greg,

I run a British 24 V C11/R210 station here which is a thirsty beast, as 
well as a GRC-9, and I use a pair of 40 ampere-hour car batteries and 
float charge them with a 25A switched-mode supply bought off ebay. To 
avoid the battery current getting back into the PSU I use a heavy-duty 
(30A) blocking diode in the positive line to the battery from the PSU. 
The PSU has a trim pot which allows me to swing the volts at the battery 
up to 27.6Vto sustain some charge. At 40aH the batteries aren't too 
large and heavy, they are basically just acting as a capacitor to 
overcome the high starting current of the dynamotors.

Hope this helps,

Roger Basford/G3VKM


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> Message: 4
> Date: Mon, 30 May 2011 17:14:00 -0400
> From: "Greg Mijal"<bluebirdtele at embarqmail.com>
> Subject: [Milsurplus] AN/GRC - 9 Power supply question
> To:<milsurplus at mailman.qth.net>
> Cc: boatanchors at mailman.qth.net
> Message-ID:<1E899068D5874863824F16EDD80AC8D9 at userdff40e0b99>
> Content-Type: text/plain;	charset="iso-8859-1"
>
> Hi:
>
> I am going to run up my GRC-9 rig for my club's field day efforts next month.
> It's going to be a demo for old technology tire-kickers sitting next to a modern SDR rig.
> My power choices are limited to the hand crank generator or energizing the 24 volt dynamotor box that came with the rig.  It's the 12 volt version of the supply that is called for in the GRC-9 system spec's.  Since I am not Arnold Swarzenneger I won't be cranking the "Radio Coffee".
>
> I found what looks like a low cost replacement for the 24 volt requirement for the dynamotor.  It's a brand new switch mode power supply that puts out 24 vdc @ 14.6 amps.  Inrush protection of up to 50 amps.  all the spec's may be read at Ebay auction # 310312941221. Pleas don't email me back something along the lines of " just put two 12 v batteries together"  There are too many disadvantages to doing it the easy way.
> Your "expereience" based input is most appreciated here.
> 73's
> Greg
> WA7LYO
> Kinston NC
>
>