Re: Complicated Napco MA2600 Internals Issue

["Katie Wasserman" <katie10543@xxxxxxxxx>]

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.  All 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.  The system needs the AC power to start up or it triggers the
alarm, there seems to be no way around this.  Putting in a fake
battery using a capacitor discharging through a diode and charging
through a parallel resistor didn't work either.  The system  does a 1
second test using the battery about 1 minute after AC startup, that's
how it determines if the battery is good.  After 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,
>
> If you can re-run your keypad cables, use shielded cable to minimize RF
> leakage from the databus. You may use shielded cable with Napco, Honeywell,
> and Bosch's data loops and keypad data cables. Consult the ARRL's RF
> Handbookhttp://www.arrl.org/catalog/6834/for more information. IMHO, you
> best bet is to scrap the old system and upgrade to something newer that
> won't generate as much RF Hash...
>
> 73,
> Russ/KN6SD