[Amps] Buck-boost xfmr

[Jim Thomson]

Date: Wed, 25 Jun 2014 21:41:36 +0100
From: David Lisney <g0fvt at hotmail.com>
To: "amps at contesting.com" <amps at contesting.com>


Hi, the power supply for the Quadra is a switch-mode, the manual seems to reckon 240v is ok.
In the UK our mains voltage is 240v, as far as I know Quadras survive that fine... I personally would run it straight off your mains supply... the buck transformer is a valid approach to sorting out the supply voltage issue... however it is vital that current is not allowed to pass through the low voltage secondary without the primary powered.
A 15v 10a transformer should do the job...
regards David G0FVT

##  I see no reason why a  10-15v @ 15A CCS  xfmr cant be used.... with NO 120 vac applied to the  120 vac primary of the buck-boost xfmr.   All that would happen is you wont get any boost-buck action. 
If you really want to get fancy, you can always install a small 0-120 vac  variac, say a 2A  CCS variac,  on the primary side of the buck-boost xfmr..and vary the amount of buck-boost you want... from  0-15 vac in this case. 

##  Having said all that,  has anybody actually blown a Quadra  up.....from line V  being too high ???    I could see transients-spikes-surges etc,  blowing it up.... but that is something that could be averted with movs at the main 200A panel etc. 

##  Interesting to note that the old Q manual sez its  rated up to 234v.  New manual sez its rated to 240 vac.    Wonder if they just changed the manual ?  

##  If you folks do try a buck-boost  xfmr, make damn sure its wired for buck..and NOT boost... or you will  be in for a rude awakening.   Test the xfmr out on a 100 watt light bulb 1st... +  DVM.  
##  Does yaesu still make the quadra ?   I see Acom has its  600 w  SS amp in production....which  will handle just about any line V  you can throw at it.   It also has power factor correction built into it.  But at $3K  a copy, I think I will pass on it..esp with the lousy IMD.  

Jim  VE7RF