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Gear / Technical Help => Remote Power => Topic started by: phishn on November 23, 2003, 10:06:36 PM

Title: Operating Voltage range for a warm mod UA-5 with phantom power on
Post by: phishn on November 23, 2003, 10:06:36 PM
Does anyone know what the operating voltage range for a warm mod UA-5 with phantom power on powering AKG 391's would be?  I built a voltmeter and watched it drop as the battery slowly died...i had power all the way down to 3 volts...but I'm sure the mics probably were not getting a full 48 v of phantom power.... At what voltage should I consider swapping out the battery pack to a fresh one?
Title: Re:Operating Voltage range for a warm mod UA-5 with phantom power on
Post by: dklein on November 26, 2003, 05:19:53 PM
I've found that once you hit 9.5 (on a 9.6v pack), you're pretty damn close to the end.  If you plot voltage over time, that's where it drops off rapidly.

btw, my 9.6v pack starts at about 11.2v

If you monitored your recording during this test, you'd find you weren't getting signal all the way through to 3v.  Also, if you're using a pc, you don't ever want this to happen.  When the power dies on my UA-5 it causes my laptop to spontaneously reboot!
Title: Re:Operating Voltage range for a warm mod UA-5 with phantom power on
Post by: phishn on November 26, 2003, 09:26:26 PM
I have seen somewhere on this board that 8.8v is the safe cutoff...not sure why or how that number came about.  The UA-5 must have a safe operating voltage range....say something like 8v-12v..but i cant find this info anywhere.
Title: Re:Operating Voltage range for a warm mod UA-5 with phantom power on
Post by: dklein on November 27, 2003, 11:56:35 AM
I have seen somewhere on this board that 8.8v is the safe cutoff...not sure why or how that number came about.  The UA-5 must have a safe operating voltage range....say something like 8v-12v..but i cant find this info anywhere.

Just to clarify, I was sort of combining this with real-life battery performance.  With my 9.6v NiMh pack, (which starts fully charged at 11.2v), once the voltage drops to 9.5, there's less than 10 minutes before it's below 6v and the whole thing is over.
Title: Re:Operating Voltage range for a warm mod UA-5 with phantom power on
Post by: phishn on November 27, 2003, 09:29:53 PM
ok..i made an inline voltmeter where i can watch the voltage..so if i see it get close to 6V, i then unplug the voltmeter, plug in the new battery, remove the old battery, then plug the voltmeter back in
Title: Re:Operating Voltage range for a warm mod UA-5 with phantom power on
Post by: dklein on November 28, 2003, 11:36:15 AM
ok..i made an inline voltmeter where i can watch the voltage..so if i see it get close to 6V, i then unplug the voltmeter, plug in the new battery, remove the old battery, then plug the voltmeter back in

huh?  What battery are you using and what's your recording chain..  If you wait until 6v I do not think the UA-5will be OK.  And if it's going into a laptop, cutting the power off while recording can be a problem.

Doing a timed test and working in the safe zone is a lot easier than monitoring voltage while you're recording.  It's easy to run 5-6 hours on a single 3000 mAh battery.  Do you need to go longer than this?

I just hate the idea of having more things to watch and more things to break or forget (like last night when I got to the venue and didn't have my stupid power cord for battery>UA-5)  >:(
Title: Re:Operating Voltage range for a warm mod UA-5 with phantom power on
Post by: phishn on November 28, 2003, 11:56:46 AM
I created a cable to power the UA-5 from a thread on here.  IT has 2 paralell connectors so a battery can be changed without interrupting the power.  I bought a cheap voltmeter at ratshack and plug that into the extra paralell connector to monitor the voltage..in case a battery goes bunk or something.  I do have a 3000 mah battery, a 1600, and a 1000.
Title: Re:Operating Voltage range for a warm mod UA-5 with phantom power on
Post by: phishn on November 28, 2003, 11:58:13 AM
if i was there dklein..i'd let ya borrow my extra cable.  i created 2 ua-5 cables in the event that something gets screwed up with one..or if someone like yourself needs to borrow one.