RF Help
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I am working on a project that is using a Transmitter. And what is
happening is the stamp is being effected by the RF from the radio.
I'm assuming it's the inputs that is seeing the RF from the radio. Is
there any way to protect the inputs from the RF from the radio???
happening is the stamp is being effected by the RF from the radio.
I'm assuming it's the inputs that is seeing the RF from the radio. Is
there any way to protect the inputs from the RF from the radio???
Comments
Mine is connected to a 1000 W RF transmitter with no problems. Even to a
section detecting forward and reflected power. Would make suggestions of
using bypass caps, ferrite beads, low pass filters and metal shielded
enclosures. Also, try an inductor (RF choke) on the power leads to the amp
and stamp depending on what you are doing. Take a look at the Radio
Amateurs Handbook if you have one available.
Possibly someone has a more direct response for you [noparse]:)[/noparse]
David
Original Message
From: Gene Shults <gshults@o...>
To: <basicstamps@egroups.com>
Sent: Sunday, April 23, 2000 7:00 AM
Subject: [noparse][[/noparse]basicstamps] RF Help
> I am working on a project that is using a Transmitter. And what is
> happening is the stamp is being effected by the RF from the radio.
> I'm assuming it's the inputs that is seeing the RF from the radio. Is
> there any way to protect the inputs from the RF from the radio???
>
>
>
>
>
>I am working on a project that is using a Transmitter. And what is
>happening is the stamp is being effected by the RF from the radio.
>I'm assuming it's the inputs that is seeing the RF from the radio. Is
>there any way to protect the inputs from the RF from the radio???
>1. Is the power for the stamp and the tX from the same source
2. What is the frequency and power of the transmitter
3. What modulation type is the transmitter
4. what inputs/outputs go to the transmitter
Answer these questions an I can provide a solution to your problem
Norm N8RGR
and even the flouresent lamps & computer trash. Installing 10K pullup or
pulldown resistors cured my problems. Any pin floating will give you
trouble. ==Mac== AG5F
>> happening is the stamp is being effected by the RF from the radio.
>> I'm assuming it's the inputs that is seeing the RF from the radio. Is
>> there any way to protect the inputs from the RF from the radio???
>
1. Is the power for the stamp and the tX from the same source
I have had the power set up both ways, connected with the same power supply
and
the radio and stamp with it's own supply. The results are the same.
2. What is the frequency and power of the transmitter
Frequency using here is 144.100 mhz
3. What modulation type is the transmitter
FM
4. What inputs/outputs go to the transmitter
What I have set up is Pins 12-15 are set for outputs
Output 15 turns on a 5 volt relay via a transistor Does nothings
but turns on/off a LED.
Output 14 turns on a 5 volt relay via a transistor that keys up
the radio and Pin 7 sends out a DTMF tone When radio is keyed up.
Pins 8-11 are set for inputs. What I have noticed is that when the radio is
keyed up via output 14 that the inputs voltage on pins 8-11 will drop to
about 2.5 volts which will trigger a false input to the inputs pins 8-11.
If I disable the transmitter and run the code again the relay at output 14
will
toggle as before and the inputs 8-11 will be stable, voltage at pins 8-11
will
be 5.02 volts.
I am using the CM8880 Decoder chip circuit also which uses pins 0-6.
The decoder is listening for tones from the radio also.
I have moved the transmitter to different locations and also remoted the
antenna
away from the circuit. The problem still occurs.
The inputs must be very sensitive to RF.
Hope this will help you to help me.
If there's anything else let me know...
Thanks
Gene
Original Message
From: Norman Hockler <norsan@b...>
To: <basicstamps@egroups.com>
Sent: Sunday, April 23, 2000 11:11 AM
Subject: Re: [noparse][[/noparse]basicstamps] RF Help
> At 02:00 PM 4/23/00 +0000, you wrote:
> >I am working on a project that is using a Transmitter. And what is
> >happening is the stamp is being effected by the RF from the radio.
> >I'm assuming it's the inputs that is seeing the RF from the radio. Is
> >there any way to protect the inputs from the RF from the radio???
>
>
>
> >1. Is the power for the stamp and the tX from the same source
>
> 2. What is the frequency and power of the transmitter
>
> 3. What modulation type is the transmitter
>
> 4. what inputs/outputs go to the transmitter
>
> Answer these questions an I can provide a solution to your problem
>
> Norm N8RGR
>
>
>
>
What is it you are trying to transmit? I am thinking about integrating a
transmitter into my basic stamp project for serial data feedback with the
debug command. Just curious to know if yours in a similar application.
~Jim
>I've had a bunch of problems with using power mfets and even a pic with RF
>and even the flouresent lamps & computer trash. Installing 10K pullup or
>pulldown resistors cured my problems. Any pin floating will give you
>trouble. ==Mac== AG5F
>
>>> happening is the stamp is being effected by the RF from the radio.
>>> I'm assuming it's the inputs that is seeing the RF from the radio. Is
>>> there any way to protect the inputs from the RF from the radio???
>>
>
>
>
resistor. But still have the problem.
Original Message
From: Robert McAtee <w5tnj@c...>
To: <basicstamps@egroups.com>
Sent: Sunday, April 23, 2000 6:39 PM
Subject: Re: [noparse][[/noparse]basicstamps] RF Help
> I've had a bunch of problems with using power mfets and even a pic with RF
> and even the flouresent lamps & computer trash. Installing 10K pullup or
> pulldown resistors cured my problems. Any pin floating will give you
> trouble. ==Mac== AG5F
>
> >> happening is the stamp is being effected by the RF from the radio.
> >> I'm assuming it's the inputs that is seeing the RF from the radio. Is
> >> there any way to protect the inputs from the RF from the radio???
> >
>
>
>
And I'm transmitting a DTMF out of pin 7.
Original Message
From: Jim Szymczak <szymczak@c...>
To: <basicstamps@egroups.com>
Sent: Monday, April 24, 2000 11:20 AM
Subject: Re: [noparse][[/noparse]basicstamps] RF Help
> I'm a little curious to know what frequency transmitter you are using.
> What is it you are trying to transmit? I am thinking about integrating a
> transmitter into my basic stamp project for serial data feedback with the
> debug command. Just curious to know if yours in a similar application.
>
> ~Jim
>
> >I've had a bunch of problems with using power mfets and even a pic with
RF
> >and even the flouresent lamps & computer trash. Installing 10K pullup or
> >pulldown resistors cured my problems. Any pin floating will give you
> >trouble. ==Mac== AG5F
> >
> >>> happening is the stamp is being effected by the RF from the radio.
> >>> I'm assuming it's the inputs that is seeing the RF from the radio. Is
> >>> there any way to protect the inputs from the RF from the radio???
> >>
> >
> >
> >
>
>
>
same problem when pin 7 is disconnected and you transmit.
Gene Shults wrote:
>
> Frequency is 144.100 mhz
> And I'm transmitting a DTMF out of pin 7.
>
>
Original Message
> From: Jim Szymczak <szymczak@c...>
> To: <basicstamps@egroups.com>
> Sent: Monday, April 24, 2000 11:20 AM
> Subject: Re: [noparse][[/noparse]basicstamps] RF Help
>
> > I'm a little curious to know what frequency transmitter you are using.
> > What is it you are trying to transmit? I am thinking about integrating a
> > transmitter into my basic stamp project for serial data feedback with the
> > debug command. Just curious to know if yours in a similar application.
> >
> > ~Jim
> >
> > >I've had a bunch of problems with using power mfets and even a pic with
> RF
> > >and even the flouresent lamps & computer trash. Installing 10K pullup or
> > >pulldown resistors cured my problems. Any pin floating will give you
> > >trouble. ==Mac== AG5F
> > >
> > >>> happening is the stamp is being effected by the RF from the radio.
> > >>> I'm assuming it's the inputs that is seeing the RF from the radio. Is
> > >>> there any way to protect the inputs from the RF from the radio???
> > >>
> > >
> > >
> > >
> >
> >
> >
the transmitter
and the same problem is there. Problem is that the 5 volts on pins 8-11 drop
to about
2.5 volts, which I have pins 8-11 set up for inputs. Which then what happens
is that the stamp
see the 2.5 volts as a input and the input is activated. Freq. operating at
is 144.100 mhz.
I have also tried changing freq. to see if there is any difference, with no
success.
Original Message
From: LarryGaminde <lgaminde@t...>
To: <basicstamps@egroups.com>
Sent: Monday, April 24, 2000 8:09 PM
Subject: Re: [noparse][[/noparse]basicstamps] RF Help
> How is the stamp being effected restarting or what, does it have the
> same problem when pin 7 is disconnected and you transmit.
>
> Gene Shults wrote:
> >
> > Frequency is 144.100 mhz
> > And I'm transmitting a DTMF out of pin 7.
> >
> >
Original Message
> > From: Jim Szymczak <szymczak@c...>
> > To: <basicstamps@egroups.com>
> > Sent: Monday, April 24, 2000 11:20 AM
> > Subject: Re: [noparse][[/noparse]basicstamps] RF Help
> >
> > > I'm a little curious to know what frequency transmitter you are using.
> > > What is it you are trying to transmit? I am thinking about
integrating a
> > > transmitter into my basic stamp project for serial data feedback with
the
> > > debug command. Just curious to know if yours in a similar
application.
> > >
> > > ~Jim
> > >
> > > >I've had a bunch of problems with using power mfets and even a pic
with
> > RF
> > > >and even the flouresent lamps & computer trash. Installing 10K pullup
or
> > > >pulldown resistors cured my problems. Any pin floating will give you
> > > >trouble. ==Mac== AG5F
> > > >
> > > >>> happening is the stamp is being effected by the RF from the radio.
> > > >>> I'm assuming it's the inputs that is seeing the RF from the radio.
Is
> > > >>> there any way to protect the inputs from the RF from the radio???
> > > >>
> > > >
> > > >
> > > >
> > >
> > >
> > >
>
>
>
UHF 10 watt and a 35 watt vhf rig, (446.0 and 146.80), as well as 3
scanners going. (Scanners also transmitt trash). My workbench is appx 4
feet from the transmitters, of course coaxed to outside antennas. The VHF
antenna is no further then 30 ft over my head. I do many hobby projects on
the bench and often transmit while there operating and never had a problem.
Be sure to advise when you find the problem.... ==Mac== AG5F / Owner and
Trustee of W5TNJ rptr.
At 08:04 PM 4/24/00 -0500, you wrote:
>Frequency is 144.100 mhz
>And I'm transmitting a DTMF out of pin 7.
Someone may have mentioned this already, but if you are not using 8-11 and
these are the ones causing the problem, at the beginning of the code make
them an output and remove your pullup resistors. Then they won't cause you a
problem. Just a thought.
David
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I am using 8-11 for my alarm inputs.
This project is going to be a alarm system.
Inputs are going to be contacts on doors and windows.
I have my two way radios interfaced into this to alert me when the inputs
are
activated and ableing me to turn the system on and off.
But with the RF causing this problem, the inputs are not stable.
When the two way radio located at the stamp transmits
it's causing the inputs to drop out, causing alarms on the inputs..
Original Message
From: David Lewis <dlewis4@h...>
To: <basicstamps@egroups.com>
Sent: Friday, April 28, 2000 7:17 PM
Subject: Re: [noparse][[/noparse]basicstamps] RF Help
> Gene,
> Someone may have mentioned this already, but if you are not using 8-11 and
> these are the ones causing the problem, at the beginning of the code make
> them an output and remove your pullup resistors. Then they won't cause you
a
> problem. Just a thought.
>
> David
> ________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
>
>
>
>
your logic on your inputs and make an intrusion send a HI signal to your
stamp.
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
Let me try that and I'll get back with you on the results..
Thanks
Gene
Original Message
From: David Lewis <dlewis4@h...>
To: <basicstamps@egroups.com>
Sent: Sunday, April 30, 2000 10:54 AM
Subject: Re: [noparse][[/noparse]basicstamps] RF Help
> Can you change your code and use pull down resistors on 8-11, then reverse
> your logic on your inputs and make an intrusion send a HI signal to your
> stamp.
> ________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
>
>
>
>