"P. Venkman" wrote in message
om...

I'm still interested in findind a way to deal with this aside from
just not using the synth module at that site. Now that I've more or
less isolated the problem, is there anything I can try? I did make an
attempt at sheilding just the RF module with no luck, but are there
other options?

As long as it's at the transmitter, you could try a bandpass filter. Chances
are the interference is coming from outside the RC band. There are programs
available for free that will give you the numbers you need. I use one called
AADE Filter Design from AADE.com . Ask if you need info on making the
inductors etc.

"PM"

"Paul_Morphy" wrote in message ...
"P. Venkman" wrote in message
om...

I'm still interested in findind a way to deal with this aside from
just not using the synth module at that site. Now that I've more or
less isolated the problem, is there anything I can try? I did make an
attempt at sheilding just the RF module with no luck, but are there
other options?

As long as it's at the transmitter, you could try a bandpass filter. Chances
are the interference is coming from outside the RC band. There are programs
available for free that will give you the numbers you need. I use one called
AADE Filter Design from AADE.com . Ask if you need info on making the
inductors etc.

"PM"

That's very useful, thanks! I downloaded the program and think I
understand it well enough to plug in the numbers. I do have one big
question though. How do I measure the impedance? I've got a basic
VOM but that's it as far as test equipment, and my knowledge of things
electronic is pretty basic.

"P. Venkman" wrote in message
om...

That's very useful, thanks! I downloaded the program and think I
understand it well enough to plug in the numbers. I do have one big
question though. How do I measure the impedance? I've got a basic
VOM but that's it as far as test equipment, and my knowledge of things
electronic is pretty basic.

Oh, yeah, I didn't consider that your antenna is not 50-ohms. How long is
the antenna, and what frequency band are you using? 72 MHz? When it comes to
calculating what your antenna looks like impedance-wise, there are others
here more knowledgeable than me and I hope they jump in! I wonder how well
shielded the transmitter is, also. If not well shielded the interference
could just get in directly and the BP filter wouldn't help. There are
devices that allow you to measure an antenna's impedance, but they cost
about what your transmitter cost.

"PM"

"P. Venkman" wrote in message
om...

That's very useful, thanks! I downloaded the program and think I
understand it well enough to plug in the numbers. I do have one big
question though. How do I measure the impedance? I've got a basic
VOM but that's it as far as test equipment, and my knowledge of things
electronic is pretty basic.

Oh, yeah, I didn't consider that your antenna is not 50-ohms. How long is
the antenna, and what frequency band are you using? 72 MHz? When it comes to
calculating what your antenna looks like impedance-wise, there are others
here more knowledgeable than me and I hope they jump in! I wonder how well
shielded the transmitter is, also. If not well shielded the interference
could just get in directly and the BP filter wouldn't help. There are
devices that allow you to measure an antenna's impedance, but they cost
about what your transmitter cost.

"PM"

"Paul_Morphy" wrote in message ...
"P. Venkman" wrote in message
om...

I'm still interested in findind a way to deal with this aside from
just not using the synth module at that site. Now that I've more or
less isolated the problem, is there anything I can try? I did make an
attempt at sheilding just the RF module with no luck, but are there
other options?

As long as it's at the transmitter, you could try a bandpass filter. Chances
are the interference is coming from outside the RC band. There are programs
available for free that will give you the numbers you need. I use one called
AADE Filter Design from AADE.com . Ask if you need info on making the
inductors etc.

"PM"

That's very useful, thanks! I downloaded the program and think I
understand it well enough to plug in the numbers. I do have one big
question though. How do I measure the impedance? I've got a basic
VOM but that's it as far as test equipment, and my knowledge of things
electronic is pretty basic.

"P. Venkman" wrote in message
om...

I'm still interested in findind a way to deal with this aside from
just not using the synth module at that site. Now that I've more or
less isolated the problem, is there anything I can try? I did make an
attempt at sheilding just the RF module with no luck, but are there
other options?

As long as it's at the transmitter, you could try a bandpass filter. Chances
are the interference is coming from outside the RC band. There are programs
available for free that will give you the numbers you need. I use one called
AADE Filter Design from AADE.com . Ask if you need info on making the
inductors etc.

"PM"

In case anyone cares I have an update on this. I was able to get a
crystal controlled RF module for the transmitter and that took care of
the problem. It's definitely the synth RF module that's experiencing
the interference.

I'm still interested in findind a way to deal with this aside from
just not using the synth module at that site. Now that I've more or
less isolated the problem, is there anything I can try? I did make an
attempt at sheilding just the RF module with no luck, but are there
other options?

Thanks.