[Icom] Need Help with IC-451A

Sat, 8 Mar 2003 07:46:42 -0700

Hello Dave,
	Thanks for the input.
	I did take a closer look and figured out that the end pins are the DC
connect. The > end is + and the other end of the connector is - but I was
beginning to think the two pins in the middle (pins 2 & 3 ref your drawing)
were jumpered together for AC.  Is this NOT the case and instead pins 1 + 2
are jumpered (ref. your diagram)???
	When I got it going on DC there is no rush sound on FM and the Receive
light doesn't stay lit so I think there is more not right with this radio.
Too bad.  I really don't need the work. ;>(  I also didn't realize it only
works from 430 to 440 and not above 440 or below 430.  OK for satellite work
but I was hoping to use it for more. Sort of makes FM a Moot mode.  I have a
251A on the way that was advertised as fully functional/not DOA so I hope I
have better luck with that one. BTW, does your 251A have a factory
tone/ctcss board in it and if so, what is the model # ??? I will assume the
one I have coming doesn't so I just want to know so I can keep my eyes open
for one.  I see I need to get a replacement bail for the bottom of the rig
as the original is missing.
	Looking forward to your reply,
Best 73

Mike Baker  K7DD
[email protected]

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of daveg
Sent: Saturday, March 08, 2003 5:22 AM
To: [email protected]
Cc: [email protected]
Subject: Re: [Icom] Need Help with IC-451A

Mike -

I have a 251A, the 2-meter version of that rig.  There needs to be a
jumper plug in that 4-pin jack for it to run on the internal 110V
supply, or you can run it from 13.8 V from that jack.   Last I knew,
Radio Shack stocked the 4-pin 'molex' plugs.   The 110V supply in mine
failed a few years ago, and this isn't the most reliable part of the
radio.   And no jumpers are needed on that large multi-pin connector.

To run it from external 13.8 VDC,  + is the pin on the triangle-shaped
end (right side, looking at the rear panel of the rig), and - is the pin
on the left side, and the two center pins are not connected.   To run
from the internal supply, there is a jumper from the pin at the
triangle-shaped (right) end to the one next to it.
                            ______
                          | 4 3 2 1 >
                           --------

In my crude attempt at drawing the connector,  jumper 1 and 2 together
for internal supply operation.
For external 13.8 VDC, 1 is positive and 4 is negative.

The internal supply uses a 2-amp fuse in the internal fuse holder.  The
external DC cord had 5-amp fuses in it.

73's
Dave, N2EPV

Mike Baker K7DD wrote:

>Hello there,
>	I just picked up a used (little did I know how used) IC-451A off E-Bay.
>Looks ok on the outside, but when I hooked up AC power, NADA.  The DC
>connector is one I don't have in my box of tricks yet so I opened it up to
>look around.  Some of the coil slugs look like they have been adjusted (PLL
>readjust perhaps) but I'll cut to the chase.  Is there a jumper used on the
>DC connector when you use the AC supply?  I ask because there are 4 wire
>connected to the 4 pins so I was wondering if there was a jumper between
the
>middle two when on AC?  That would account for the AC supply not working at
>this point.  ALso, there is an UGLY large multipin molex connector for
>accessories.  Is there supposed to be a jumper plugged into it during
normal
>opperation?
>

>
>

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