Receiver Help

[subicman]

Ok gents, I have a problem and I need some help. I recently bought a GWS R-6NII 6 channel receiver from the Robot Market place. I specified a Futaba negative shift 75 mhz FM requirement with a xtal on channel 78. I received a new in the box FM receiver labeled with two stickers (75 mhz band, and F for futaba) and a UM-1 xtal that says channel 78 75.750. Using my Futaba 8UAF, which has been verified as being set properly on PPMand channel 78, I do not get any response on the receiver. I can plug a known good servo into any of the channels and a freshly charged receiver battery into it and the servo will twitch indicating it has power, but when I move a stick or knob, ther is no movement. I have talked with other people who have had no problems with this combo or similar combor of transmitter and receiver, but nobody can say why mine isn't working. I get blank stares, and a it should work. Could the xtal be bad?

Tim

[JWLaRue]

Re: Receiver Help

What model Futaba receiver? Could it be a PCM receiver?

-Jeff

[Guest]

Re: Receiver Help

My R-4P (or R-6N) receiver is not working, how do I figure out what's wrong?

Pay special attention to number three. Some transmitters enable you to switch between negative and positive shift (for instance my Sanwa RD6000 allows this). I'm not sure about your Futaba set

1. First, test the R-4P/R-6N without using the ESC. This is done by connecting a 4.8V battering directly on port 4 (or 6) of the receiver. Make sure when you connect the battery that you observe the proper polarity of the pins. If you connect this incorrectly, the R-4P/R-6N will not work.
2. Once the battery is connected to port 4 (or 6), put a servo into ports 1, 2, and 3. Turn on your transmitter and test the sticks to determine which port is elevator, rudder, and throttle. Different transmitter manufacturers use different ports for different functions.
3. If your R-4P/R-6N still does not work after step 2, you may not be using the correct type of transmitter. You must have a FM (PPM) type transmitter. An AM or PCM type transmitter will not work. Also, you must also have the correct "transmitter shift". A negative shift R-4P/R-6N will have an F on top of its plastic case. A positive shift R-4P/R-6N will have an J on top of its plastic case. Futaba/Hitec transmitters have negative shift. JR/Airtronics have positive shift.
4. If your R-4P/R-6N still does not work after step 2, then you may have a bad or cracked UM1 crystal. Replace the crystal and repeat step 2. If after repeating step 2 and your R-4P/R-6N still does not work then you have a bad receiver.
5. Now that you have determined which ports are used for elevator, rudder, and throttle, you can install the ESC. If the R-4P/R-6N does not work, then your ESC is bad or burnt out.

[subicman]

Re: Receiver Help

My R-4P (or R-6N) receiver is not working, how do I figure out what's wrong?

Pay special attention to number three. Some transmitters enable you to switch between negative and positive shift (for instance my Sanwa RD6000 allows this). I'm not sure about your Futaba set

1. First, test the R-4P/R-6N without using the ESC. This is done by connecting a 4.8V battering directly on port 4 (or 6) of the receiver. Make sure when you connect the battery that you observe the proper polarity of the pins. If you connect this incorrectly, the R-4P/R-6N will not work.
2. Once the battery is connected to port 4 (or 6), put a servo into ports 1, 2, and 3. Turn on your transmitter and test the sticks to determine which port is elevator, rudder, and throttle. Different transmitter manufacturers use different ports for different functions.
3. If your R-4P/R-6N still does not work after step 2, you may not be using the correct type of transmitter. You must have a FM (PPM) type transmitter. An AM or PCM type transmitter will not work. Also, you must also have the correct "transmitter shift". A negative shift R-4P/R-6N will have an F on top of its plastic case. A positive shift R-4P/R-6N will have an J on top of its plastic case. Futaba/Hitec transmitters have negative shift. JR/Airtronics have positive shift.
4. If your R-4P/R-6N still does not work after step 2, then you may have a bad or cracked UM1 crystal. Replace the crystal and repeat step 2. If after repeating step 2 and your R-4P/R-6N still does not work then you have a bad receiver.
5. Now that you have determined which ports are used for elevator, rudder, and throttle, you can install the ESC. If the R-4P/R-6N does not work, then your ESC is bad or burnt out.

Ok, 1, 2 and 3 all completed No go. On to buy another UM-1 Thanks......Where did you find this thing? The GWS website was not very helpful in my opinion, unless I missed it.

Tim

[Guest]

Re: Receiver Help

http://www.bphobbies.com/view.asp?id=A0320045

[subicman]

Re: Receiver Help

Thanks again...have new xtal on way. will try again then. I know i never hooked battery up wrong so that is not problem.

Jeff, have a T8UAF its is selectable between PPM and PCM. I verified it was selected to PPM. Using a Channel 78 75mhz module

Tim

[JWLaRue]

Re: Receiver Help

Tim,

Good to know that the PCM-PPM question can be discarded.

Do you have any other crystal sets (xmtr-rcvr) that you can try instead of waiting for a new one to show up?

-Jeff

[subicman]

Re: Receiver Help

Jeff,

I have another receiver that has a Polk seeker 6 in it and it takes the input from the transmitter module just fine. The module is a synthesized channel 78, there is no crystal in it. i have another module that is channel 73 with a xtal but i don't have another receiver xtal. The GWS takes a micro sized cyrstal anyway, so i would have to wait anyway

Tim

[JWLaRue]

Re: Receiver Help

Drat.

[ramius-ii]

Re: Receiver Help

You may wish to look at this link written by others who have the same receiver. http://www.rcgroups.com/forums/showthread.php?t=488021

Best, Ed

[bigdave]

Re: Receiver Help

I use the GWS R/X's in a few of my smaller models and have had no problems.
Hopefully is is just a bad crystal. BD.

[subicman]

Re: Receiver Help

Ok, got the new crystal in. No luck......pulling my hair out. Really wanted to use this in my Thor Sturgeon.

Tim

[ramius-ii]

Re: Receiver Help

It is possible that somehow you may have blown the front-end of the receiver or you received it non-functional. The antenna connects to a FET (Field Effect Transistor) and most are sensitive to static electricity. Such static can be contained in the packing "peanuts". If you know a amature (ham) radio operator they may be able to assist as they typically have or have access to the necessary test equipment.

Best, Ed

[raalst]

Re: Receiver Help

just a silly one : when testing, were you sure the battery was delivering 4.8 volts minimum ? (and about 6 max)
if you have large current "consumers" hooked up to the battery like large motors, shorts or faulty servo's,
the voltage might drop to levels that hamper the operation of the receiver.

[subicman]

Re: Receiver Help

fully charged battery at 5.1 volts and 1 5 gram servo (known good) attached. no large loads. I was just testing it out.