Re: Complicated Napco MA2600 Internals Issue

["Jim" <alarminex@xxxxxxx>]

On Mar 1, 10:12=EF=BF=BDpm, "Katie Wasserman" <katie10...@xxxxxxxxx> wrote:
> Russ, Thanks for the suggestion and ARRL pointer but rewiring isn't an
> easy option.
>
> But I did try GQC's idea of using bypass capacitors on all the lines
> and that made a huge different, especially on the keypad lines, noise
> dropped by almost 15db. =A0All of the noise is/was coming from the alarm
> wiring, running running on the battery alone gives the same noise
> level, so the AC line choke wasn't needed.
>
> Jim, your idea of running off the battery power feed only doesn't
> work. =A0The system needs the AC power to start up or it triggers the
> alarm, there seems to be no way around this. =A0Putting in a fake
> battery using a capacitor discharging through a diode and charging
> through a parallel resistor didn't work either. =A0The system =A0does a 1
> second test using the battery about 1 minute after AC startup, that's
> how it determines if the battery is good. =A0After that point it seems
> to do a battery check each time the system is armed. So you really do
> need to have a real battery in there (or a giant capacitor) to make
> this alarm function.
>
> Thanks to everyone for you help on this.
>
> 73,
> Kaite (k1kdx actually k1kdx/ae)
>
> On Mar 1, 9:28 pm, "Russell Brill" <russwbr...@xxxxxxxxxxxxx> wrote:
>
>
>
> > "Katie Wasserman" <katie10...@xxxxxxxxx> wrote in message
>
> >news:1172612240.730476.162430@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> Jim,
>
> > > That's a great idea and I do have full access to the programming.
>
> > > Thanks!!!
>
> > > -Katie
>
> > Katie,
>
Did you try to apply 12VDC to one of the AC terminals?

I've got a few Napco and other manufacturers systems running on 12VDC
only on boat alarms. Never used a 2600 for this application though.
Applying 12VDC to one of the AC terminals has worked for me as far as
fooling the system into thinking AC was applied. When the power is
removed from these units and restored, there is no indication of AC
power loss or low battery. I have no idea whether running it this way
will reduce the RF emissions.

My original suggestion to you about powering the unit this way,  was
following up on your method of wanting to shut the system down while
you were transmitting. I still didn't check the installation
instructions but did you investigate whether you can program the panel
to ignore an AC power loss?

Another thought occured to me also, regarding the "sequencing" of the
application of AC and DC. If I remember correctly ( ie. I could be
wrong) when you power up the panel, there is a momentary "blip" on the
output of the siren. This might mean that the Aux relays are being
momentarily "pulsed" too. You may be able to utilize this momentary
closure of the Aux contacts to pic another relay that would lock in.
This relays contacts hooked in series with the positive lead of the
battery, could then apply the DC voltage a split second after AC is
applied.