Complicated Napco MA2600 Internals Issue

[Katie Wasserman]

I've been reading some of the expert posts here and I know that you're
the right group for this one.....


I have a Napco MA2600 system in my house and find that it generates a
lot of RF noise from below 300KHz up to 2MHz. Bad enough for
listening to AM radio but I recently got interested in ham radio and
that makes the problem much worse. The RF noise is coming not just
from the AC line but from all the contact wiring throughout the house
so it's not easy to get rid of.

My solution is to shut down the alarm system completely and although
this works it's a pain to bring it up and down so I've set up a system
to do that remotely. The "system" is a remotely control relay that
cuts off the low voltage AC into the control panel and simultaneously
the 12V battery supply. The cutoff function works great! But when
the system powers back up it sets off the alarm unless the AC is
applied first followed by a delay of a few seconds then the 12V
battery can be connected up.

I suppose the I could ehnace my relay circuit to add the needed delay,
but I just assume not even bother with the 12V battery and run the
system without that. Of course you can't just pull the battery on
this system since the controller is busy with alternately charging and
checking it all the time and if it finds it's not there it won't let
you arm it. There's no detail on the charging/checking battery system
in the manual. If I had a schematic I'm sure that I could figure it
out but finding one seems to be an impossible task.

So I'm looking for ideas along the lines of one of these, or maybe
something entirely different.

1) There's obviously an "AC power good, ready to accept 12V battery
voltage" signal somewhere in the panel. If I can access that point I
can use it to control the relay for the 12V battery and not use a
fixed (and unreliable) time delay. Where is it? There's some mention
of an optional PS3002 power supply that hooks into the control panel
through lugs E7 an E18. Could one of these be the point that I'm
looking for, I haven't done any circuit probing yet.

2) Faking out the battery check with a dummy battery of some sort
doesn't seem to be a workable solution, since if it really thought the
battery wasn't there when the AC power was applied it would set of
the alarm. Turning off the battery check completely seems like it
would work but I have no idea how to do this.

3) Find some magical way to eliminate the RF noise.

4) Throw the whole thing out and buy a different system.

Thanks,

Katie

 

[I brive a dus]

I've been reading some of the expert posts here and I know that you're
the right group for this one.....

I have a Napco MA2600 system in my house and find that it generates a
lot of RF noise from below 300KHz up to 2MHz. Bad enough for
listening to AM radio but I recently got interested in ham radio and
that makes the problem much worse. The RF noise is coming not just
from the AC line but from all the contact wiring throughout the house
so it's not easy to get rid of.

My solution is to shut down the alarm system completely and although
this works it's a pain to bring it up and down so I've set up a system
to do that remotely. The "system" is a remotely control relay that
cuts off the low voltage AC into the control panel and simultaneously
the 12V battery supply. The cutoff function works great! But when
the system powers back up it sets off the alarm unless the AC is
applied first followed by a delay of a few seconds then the 12V
battery can be connected up.

I suppose the I could ehnace my relay circuit to add the needed delay,
but I just assume not even bother with the 12V battery and run the
system without that. Of course you can't just pull the battery on
this system since the controller is busy with alternately charging and
checking it all the time and if it finds it's not there it won't let
you arm it. There's no detail on the charging/checking battery system
in the manual. If I had a schematic I'm sure that I could figure it
out but finding one seems to be an impossible task.

So I'm looking for ideas along the lines of one of these, or maybe
something entirely different.

1) There's obviously an "AC power good, ready to accept 12V battery
voltage" signal somewhere in the panel. If I can access that point I
can use it to control the relay for the 12V battery and not use a
fixed (and unreliable) time delay. Where is it? There's some mention
of an optional PS3002 power supply that hooks into the control panel
through lugs E7 an E18. Could one of these be the point that I'm
looking for, I haven't done any circuit probing yet.

2) Faking out the battery check with a dummy battery of some sort
doesn't seem to be a workable solution, since if it really thought the
battery wasn't there when the AC power was applied it would set of
the alarm. Turning off the battery check completely seems like it
would work but I have no idea how to do this.

3) Find some magical way to eliminate the RF noise.

4) Throw the whole thing out and buy a different system.

Thanks,

Katie

It could be time for you and Paul to check out some new headphones.

 

[Jim]

I've been reading some of the expert posts here and I know that you're
the right group for this one.....

I have a Napco MA2600 system in my house and find that it generates a
lot of RF noise from below 300KHz up to 2MHz.  Bad enough for
listening to AM radio but I recently got interested in ham radio and
that makes the problem much worse.   The RF noise is coming not just
from the AC line but from all the contact wiring throughout the house
so it's not easy to get rid of.

My solution is to shut down the alarm system completely and although
this works it's a pain to bring it up and down so I've set up a system
to do that remotely.  The "system" is a remotely control relay that
cuts off the low voltage AC into the control panel and simultaneously
the 12V battery supply.  The cutoff function works great!  But when
the system powers back up it sets off the alarm unless the AC is
applied first followed by a delay of a few seconds then the 12V
battery can be connected up.

I suppose the I could ehnace my relay circuit to add the needed delay,
but I just assume not even bother with the 12V battery and run the
system without that.  Of course you can't just pull the battery on
this system since the controller is busy with alternately charging and
checking it all the time and if it finds it's not there it won't let
you arm it.  There's no detail on the charging/checking battery system
in the manual.  If I had a schematic I'm sure that I could figure it
out but finding one seems to be an impossible task.

So I'm looking for ideas along the lines of one of these, or maybe
something entirely different.

1)  There's obviously an "AC power good, ready to accept 12V battery
voltage" signal somewhere in the panel.  If I can access that point I
can use it to control the relay for the 12V battery and not use a
fixed (and unreliable) time delay.  Where is it? There's some mention
of an optional PS3002 power supply that hooks into the control panel
through lugs E7 an E18.  Could one of these be the point that I'm
looking for, I haven't done any circuit probing yet.

2)  Faking out the battery check with a dummy battery of some sort
doesn't seem to be a workable solution, since if it really thought the
battery wasn't  there when the AC power was applied it would set of
the alarm. Turning off the battery check completely seems like it
would work but I have no idea how to do this.

3) Find some magical way to eliminate the RF noise.

4) Throw the whole thing out and buy a different system.

Thanks,

Katie

I don't know how your system is programed but if it isn't programed to
alert on AC fail, just get a power supply with a back up battery and
power the system through the battery terminals only. No AC to the
panel at all. Do you have access to the dealer programing? If you do,
and the system is giving you an AC fail signal, I think you can
program it to not alert to an AC power failure. I'd have to check the
manual to be sure, however. Let me know if you have access.

If not, some panels can be fooled into thinking that AC is applied
just by applying 12 VDC to one of the AC terminals. I don't remember
if the 2600 can do this or not. You may have to follow some circuitry
on the board to find out if they're using a bridge rectifier or not or
which of the AC terminals to use.

 

[Katie Wasserman]

Jim,

That's a great idea and I do have full access to the programming.

Thanks!!!

-Katie

 

[GQC]

Try
1 choke coil on the low voltage AC panel input

2 use .01 capacitors in parallel, on each of the alarm zone negative
terminals and tie to battery ground. This will bleed off any AC from
the zone cables and block the DC to battery ground. Do the same with
keypad terminals. This will help nullify induced AC noise from nearby
110VAC lines and induced RF noise from flourescent lights.

This has worked for me for years. Alarm companies have sent me to
their troublesome panels. However, I never did tell them what my
solution was - aka guaranteed income !

gqc

 

[Katie Wasserman]

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)

 

[Jim]

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)

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.

 

[Jim]

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)

Oh, and by the way, you didn't say whether you used and actual 12VDC
*Power supply* on the battery leads. Using a makeshift rectifier
isn't the same thing as a regulated power 12VDC power supply. A fixed
12VDC power supply, I'm pretty sure, would fool the "battery check"
sequence. The panel just wants to know that there is 12VDC there. A
half wave rectifier or a charged capacitor is likely not going to
work. After addressing supplying a sufficent battery source, it would
simply be a matter of applying AC first, which my previous post may
allow you to do.

 

[Katie Wasserman]

Jim,

When I applied DC power to the battery terminals, I used real DC for
my test -- I just used the backup battery! No need to make up a real,
filtered and regulated supply for this quick test.

Yes you can indeed put 16V DC to the AC input terminals, and that
will work fine (you need 16 volts or so because the system really runs
at 14 volts, the level set by the regulator after the full-wave bridge
that the AC input feeds into). I also changed the programming to
ignore the AC power failure, as you suggested. But the problem is
still that the system won't let you arm it if there's isn't a backup
battery in place and using just the backup battery for startup sets
off the alarm.


You really do need to sequence the startup by feeding power to the AC
input (even if you put DC there) followed by 12VDC to the backup
battery terminals some 5 seconds later (after the click that you
mentioned). If you feed power to the backup battery terminals before
the 5 seconds have elapsed (but after the AC input has been applied)
the alarm will trigger but reset itself once the 5 second click goes
off.

Your aux relay delay idea doesn't really help since you need to wait
for the 5 second click and that seems to be coming from a relay in the
middle of the panel -- not accessible. (The aux relay click happens
instantly after AC is applied and you do get the very quick beep that
you mentioned most of the time.) So I'm left with the original idea
of just using a fixed 10 second or so delay after applying AC before
connecting the backup battery. I may end up doing exactly that, but
for now I'm going to see if I can live with the bypass capacitor
solution. I might try to enhance this some by bypassing at both ends
of the keypad wire runs.

-Katie

 

[Frank Olson]

Jim,

When I applied DC power to the battery terminals, I used real DC for
my test -- I just used the backup battery! No need to make up a real,
filtered and regulated supply for this quick test.

Yes you can indeed put 16V DC to the AC input terminals, and that
will work fine (you need 16 volts or so because the system really runs
at 14 volts, the level set by the regulator after the full-wave bridge
that the AC input feeds into). I also changed the programming to
ignore the AC power failure, as you suggested. But the problem is
still that the system won't let you arm it if there's isn't a backup
battery in place and using just the backup battery for startup sets
off the alarm.


You really do need to sequence the startup by feeding power to the AC
input (even if you put DC there) followed by 12VDC to the backup
battery terminals some 5 seconds later (after the click that you
mentioned). If you feed power to the backup battery terminals before
the 5 seconds have elapsed (but after the AC input has been applied)
the alarm will trigger but reset itself once the 5 second click goes
off.

Your aux relay delay idea doesn't really help since you need to wait
for the 5 second click and that seems to be coming from a relay in the
middle of the panel -- not accessible. (The aux relay click happens
instantly after AC is applied and you do get the very quick beep that
you mentioned most of the time.) So I'm left with the original idea
of just using a fixed 10 second or so delay after applying AC before
connecting the backup battery. I may end up doing exactly that, but
for now I'm going to see if I can live with the bypass capacitor
solution. I might try to enhance this some by bypassing at both ends
of the keypad wire runs.

-Katie

Hi Katie:

You're "racking" your brains for a solution and IMHO just spinning your
wheels. Change out the panel and keypads. It's time to retire that old
Napco job. Send it to Jim Rojas (http://www.tech-man.com). I'm sure
he'll find someone "in need" for parts.