the biggest problem with trying to figure out wire colors especially with
mobile rigs, is that offten the wire is not a solid red or black...there are
usually red strips on black wire indicating the red wire...so you would have
to find just the right spot to check with the color identifier to find out
what the color really is.
Barring that, you could always check the fuse holders since i am pretty sure
they are always solid red or black depending on which lead they are in.
Too bad none of the accessible talking meters has a function to tell you the
polarity of a 13.8 volt system...i know there are instruments that can
though.
73
Colin, V A6BKX
----- Original Message ----- 
From: "Louis Kim Kline" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, May 27, 2006 10:26 PM
Subject: A Bad Scare


> Hi.
>
> Earlier in the week, I bought a Mirage B5018G amplifier, and today I
> decided to hook it up.  I had gotten someone to eyeball the connectors,
and
> I put braille labels on the connectors to keep them straight once my
friend
> described the back panel layout.
>
> Tonight, I decided to hook it up, and after putting wire ends on the power
> leads to facilitate connecting it to a power supply, I noticed that I
> didn't have the loads balanced very well between the two power
> supplies.  So I started shuffling radios around until I had a better
> distribution of current loads on the two power supplies in my
> station.  Unfortunately I hit a snag when I started reconnecting radios
> after swapping them around on the two supplies--nothing on the Astron
RS35M
> seemed to be working.  I was getting pretty frantic as the inoperative
> radios included my Kenwood TW4000A, my Kenwood TS790A, my Kenwood TM3530,
> my Ten Tec Argonaut 509 and a couple of DSP filters.  After disconnecting
> things, I discovered that the TW4000A was working when it was the only
> thing on the power supply.  The supply stayed up as I started connecting
> various things until I got to the TM3530 whereupon the power supply
> immediately shut down again.
>
> I keep my polarities straight by putting either a piece of electrical tape
> or cable ties on the negative lead, but I smelled a rat with the '3530
> because I had purchased it used from another blind ham.  So I disconnected
> it and ran next door to the neighbor's house to find out what color the
> wire with the piece of tape on it was.  Sure enough, it was
> red.  Fortunately, I didn't smell any smoke, and I was hoping that the
> reason the supply shut down was because there was a diode connected acros
> the power leads to short them when reverse polarity was applied.  Two
> thought were running through my mind--what a pain in the rear it was going
> to be if I had lost the power supply,and how much fun I would have trying
> to find another 220 MHz radio at this stage of the game.
>
> I changed the tape on the TM3530 cord to be consistent with the remainder
> of the wiring in my station, and figured that I had little to lose by
> trying to hook it up again.  Fortunately when I reversed the leads
> everything was working again.  I can't figure out why I didn't blow the
> fuses in the TM3530 though.  I was surprised that the over current
> circuitry in the Astron worked like it was supposed to, because I have
> destroyed a couple of older Astron supplies by accidentally shorting them.
>
> By the way, has anyone found a color probe that is sensitive enough to
pick
> up the color of the insulation on a piece of wire?  That would have saved
> me a lot of grief today.
>
> 73, de Lou K2LKK
>
>
>
> Louis Kim Kline
> A.R.S. K2LKK
> Home e-mail:  [log in to unmask]
> Work e-mail:  [log in to unmask]
> Work Telephone:  (585) 697-5753
>
>