[Milsurplus] Harris RF-110/112 combo: Single-phase possible?

[WA5CAB at cs.com]

Bruce,

I have no familiarity with the RF-112A, but the short answer, if it has a 
3-phase transformer (and not three single-phase transformers) is no.  You can't 
run it off of single phase.  The Lambda unit as I currently understand it, 
turned out to be a transformerless supply, using the pole pig as its input 
transformer.  Thus it was three single phase supplies whose DC output was summed.  
Operating it from single phase amounted to operating two of the three supplies, 
taking a 33% power hit, and having 120 Hz instead of 180 Hz ripple on the 
output.  And letting the third supply sit dormant (built in spare as it were).  

The long answer is that you might talk to somone who sells phase converters 
for operating 3-phase motors off of single phase lines.  I've never talked to 
anyone who has used one to run a 3-phase power supply.  I suspect that it might 
have a better chance of working if the Harris were only run AM or FSK  but it 
would be worth looking into.

And if you get an honest answer, please post it back here, as I've been 
thinking of trying to acquire an AN/URT-23 and the 3-phase supplies seem to be more 
plentiful than the single phase ones.

In a message dated 5/12/2007 9:02:21 PM Central Standard Time, 
kyrrin at bluefeathertech.com writes: 
> Fellow techies,
> 
>     The recent thread about the three-phase high-current switching supply, 
> and some tricks to use it on single-phase, got me thinking about a Harris 
> RF-110A kilowatt linear amp I have, along with its RF-112A three-phase power 
> supply.
> 
>     Specifically (and I'm going to probably need someone who knows this 
> hardware to answer this): Is there any way at all I could run the RF-112A off of 
> 220V single-phase (well, two-phase if you want to get technical about it -- 
> two hots plus a neutral)? I've looked at the schematic for the 112, and found 
> that the main power transformer primaries are a bit of a complexity 
> nightmare. I'm not well-versed enough in polyphase circuits to recognize more than 
> some of it.
> 
>     Failing any sort of tweaks or mods to the 112, I would have to find an 
> RF-124 power supply, which was designed to run the amp off single-phase to 
> begin with. More specifically, I'd have to find it within local-pickup distance 
> (west coast from WA State to the Bay Area), considering that there's no way I 
> could handle shipping on something that heavy.
> 
>     So: Any mods? Or does someone have an RF-124 power supply they don't 
> need, and that's within striking distance for me?
> 
>     Thanks much.
> 

Robert Downs - Houston
<http://www.wa5cab.com> (Web Store)
MVPA 9480
<wa5cab at cs.com> (Primary email)
<wa5cab at houston.rr.com> (Backup email)
   
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