It is more expensive to provide a dual primary transformer so Astron supplies single primary transformers. You either order it for 120 or 240, no switching back and forth.
On way to still use the supply on 120 may be to find a 120 to 240 isolation transformer on ebay. They can be had for around $15.00 or so. 73 Gary K4FMX > -----Original Message----- > From: Repeater-Builder@yahoogroups.com [mailto:Repeater- > [EMAIL PROTECTED] On Behalf Of Doug Bade > Sent: Wednesday, March 28, 2007 12:20 PM > To: Repeater-Builder@yahoogroups.com > Subject: RE: [Repeater-Builder] 220VAC Astron > > Gary; > I know the 120v versions are as you say, 120 only ( at least > every Astron non -switcher I ever worked on) , I just did not know > if the 220 versions may use a split primary transformer.. The 120 > versions definitely do not allow for mod to 220.. :-) > Fortunately, many vendors use an international capable > transformer when they go to 220, I just do not know if Astron is one of > them... > > He may get lucky ??? > > Doug > KD8B > > At 11:47 AM 3/28/2007, you wrote: > > >Astron power supplies don't normally come with dual primaries. > > > >73 > >Gary K4FMX > > > > > -----Original Message----- > > > From: > > <mailto:Repeater-Builder%40yahoogroups.com>Repeater- > [EMAIL PROTECTED] > > [mailto:Repeater- > > > <mailto:Builder%40yahoogroups.com>[EMAIL PROTECTED] On > > Behalf Of Doug W7FDF > > > Sent: Wednesday, March 28, 2007 11:39 AM > > > To: > > <mailto:Repeater-Builder%40yahoogroups.com>Repeater- > [EMAIL PROTECTED] > > > Subject: [Repeater-Builder] 220VAC Astron > > > > > > I recently took delivery [an eBAY item] of a rack mounted Astron model > > > RM-20MBB-220 20 amp power supply that is wired for 220 vac. I have no > > > schematic [yet] on this unit however I did find a similar power supply > > > schematic [RM-50MBB] that shows a standard primary and standard > > > secondary with no provision to change the input voltage. Yes, I did > > > plug in the provided ac power cable to my 120vac mains and the unit > > > does power up but, with an indicated dc voltage of around +12.0 volts. > > > > > > So my question is, has anyone on this list converted a similar 220 vac > > > power supply to 120 vac and if so, what did you do? Many thanks!! > > > > > > Doug W7FDF > > > Vail, Arizona U.S.A. > > > > > > > Yahoo! Groups Links > > >
