Ed

Can a small speaker, or earpiece be attached to the output of a receiver to act as a monitor ? We use to do this years ago using superhet receivers, but I am not sure if it can be done with present day receivers ?

Lynx

What you're talking about isn't practical, you're best off purchasing a had held scanner and just tuneing in your radio's channel.

Ed

Please explain why not ?

strato911

Just my opinion, but that would seem like a tragic waste of battery capacity (and needless noise), except when the plane is lost after a crash.

There are products on the market (inexpensive) which sound an alarm when the receiver no longer receives a signal, so after a crash, you just turn off your Tx and follow the sound.

Ed

Errrr, you don't understand Strato. A "Monitor", is used on the ground, to determine if you have a clear frequency to fly on.

Lynx

Because GeeBee it's used only on the ground, what point is there to have one in a receiver that's designed to work in the air? It adds weight complexity and yet another failure point (regardless of weather or not it's being used) That's why they only make stand alone units.

strato911

Ahh - that's a bit clearer now.

I didn't think of that since my Tracker II has an integrated scanner which won't even turn on the RF circuitry until it verifies there's no interference on your channel.

Ed

........ Ohi Vey ......... I give up already.

One more time, and then I will give up. - A monitor is used on the ground to "monitor" the frequency that you are using. IT IS NOT USED IN THE AIRPLANE ! It is used on the GROUND, just like a scanner, except that it just listens to a single channel, preferably the channel that you are using. It is used used to check for potential interference on your frequency before you fly.
YOU DO NOT INSTALL IT IN YOUR AIRPLANE ! ! !

If you do not understand this long used concept. please do not reply.

strato911

Thanks to your earlier post I DO understand what you meant.

IF you want to, you could still hook one up. The PPM pulses which the Rx would normaly send to a servo create a quiet, but audible sound if a speaker is hooked up between the servo signal wire and ground.

If the Rx has no incoming signal, it doesn't send anything to the servos, so no sound from the speaker.

Ed

Thanks Strato, you are right. Easy enough to try, and I have plenty of spare Rx's. That'll answer my question best. I'll build up a small unit that will fit in my shirt pocket.

Thanks > Jim

strato911

Jim - I tried it even before I replied... It works, but like I said, it isn't very loud. Perhaps a speaker with a different impedance would have been louder (mine was 8 ohm)... or add an audio amp with volume control

Ed

Since it will only be used for a quick pre-flight check, and only used occasionally, maybe even just an earpiece.

Lynx

Sorry GeeBee but from what you asked that would have to go up with the airplane as the receiver is definitely used on the plane. A handheld scanner is used for exactly what you're talking about, it can be tuned to listen to see if anything is transmitting anywhere on the 72mhz band and stop and listen to whatever specific channel it finds is broadcasting as well as be used to monitor any specific channel that you want. It might be more expensive than what you're intending but it's the only practical solution aside from a stand alone purpose built channel scanner for RC work.

Ed

Lynx, you just don't get it ! You are not on board yet. The receiver used in a Monitor stays on the GROUND !

SHEECH ! Read the posts, and then try and understand what you are reading !

Moderator, this guy has gotta be trolling. Please close the thread.

Lynx

Man people around here sure get cranky every now and then. <shrug>

C_Watkins

My Feedback: (10)

Well... I can understand the frustration, a bit. I got frustrated just reading it

Look at the line you quoted, and try to imagine how an earpiece would do any good,
if it was installed in the plane. Receivers can be powered up in lots of places
besides planes. I know a person once who rigged an old transmitter with servos
from the inside... and a receiver, battery, etc... so you could follow someone's stick
movements while they were flying. (for standard 4-channel setups, of course)