Radio problems... How to test output?

[rcboatlover]

Our club bought a "frequency scanner" this year to test the output of our remotes when problems arrise and to see if any one in area is running on the same channel before we start running our boats.

This week I had some problems with my radio and they gave me the scanner to take home and test my remote.

The question I have is if this is piece of equiptment is the right tool for the job? It's a communications reciever made by Yaesu model # VR-500. To me this "frequency scanner" looks and works like a big police scanner. It will recieve any signal from 100khz to 1300mhz and display the strength of the signal.

I tried it with my remote and according to the scanner it was transmitting on every channel in the 75mhz band at full strength! Sorry, but I don't beleve that. I ran my boat with several others on Sunday and it would have sent every one out of controle. As a test I tried it with my cordless phone and it gave me the same results. It blead over to several channels even with the phone 100 feet away.

Is this what others are using to test thier radios??? Shouldn't we have bought a frequency counter instead of this thing???

Looks like a cool toy, but a very poor tool.

Thanks in advance for your input!

Dale P.

 

[Dan_Cousin]

R/C frequencies are 20KHz apart and you scanner can resolve that fine of frequency resolution.

You might be standing too close to it and overloading the input. That will spew harmonics all over and mess up the reading. The transmitters are powerful.

 

[piper_chuck]

Leaving the scanner out of the picture, have you tried a range check with your radio? To do this, you turn on the transmitter with the antenna all the way down. Then turn on the receiver. Walk away from the boat while moving the rudder. You should be able to get quite a ways from the boat (with planes I typically walk about 100 feet away) and still have control of the radio. Be sure to not point the transmitter antenna directly at the boat, this significantly reduces the range.

What kind of problems are you having with the radio?

 

[Propjockey]

Hey Dale....I noticed in the Yaesu description that your model is a wide band receiver. Not sure if that makes a difference.

Tower has frequency checkers specifically for RC use.

Frequency Checker

 

[rcboatlover]

The problem with my radio is range issues. My fail safe keeps kicking in on the pond. I tested the range on shore with the engine off and its does the same thing. I can only get 20 feet away with the antenna down. I tested all the batterys, switches, connections, changed to my back up reciever, etc. But still have the same problem. I'm gong to try running the boat with someone elces transmitter this week to see if that is the problem. I have a JR FM remote and it's still under warentee. I'll have to send it in if I don't find a problem with my set up.

PJ, I got Towers new flyer in the mail last night and saw that item. Looks handy and a good buy for $45.00. I think that is what our club should have bought instead of this scanner. Any one ever use a frequency counter in the past? Looks like they would do a great job too.

Thanks for the help!

Dale P.

 

[Mick J]

Dale, Freq counters can be great for certain applications, however, personally I don't think this would be one of them. If you wish to bench level test your system/s I personally think you'd be best off using a Communications Service Monitor (CMS 52/53, 2945A etc), amongst other things. This test set will allow you to test centre freqs, pwr levels, lobes and all other kinds of funky things that go on in the RF (Radio Frequency) output stages of your Tx (my personal weapon of choice)....................that said, very expensive piece of equipment to own, calibrate, maintain and not easily accesible to the general technician (I work in a calibration laboratory so I have heaps of funky bits at my disposal so to speak), but that isn't too practical for your application.

IMHO, your club would be best off with a little freq tester (Tower) as they are inexpensive and will do the job to a satisfactory level for yourselves to establish a base line of what's around the traps at the time of testing without going into the nitty gritty of pwr levels, centre freqs, harmonics etc which will confuse the issue further (and you don't need to be a "rocket scientist" to drive it)

One thing that may very well be worthy of trying is an Xtal change, have you done this?? If you have, did you get the same result??

Has your radio been certified and/or aligned recently (as it may be experiencing some freq drift etc if it's an older model, or the bands have been changed)??

Do you know any electronics/RF technicians in your local area, they should be able to assist you trouble shoot it in some way

Interesting all the same, hope you have a win with it mate

Johno

 

[Scooter12195]

The problem with my radio is range issues.  My fail safe keeps kicking in on the pond.  I tested the range on shore with the engine off and its does the same thing.  I can only get 20 feet away with the antenna down.  I tested all the batterys, switches, connections, changed to my back up reciever, etc.  But still have the same problem.  I'm gong to try running the boat with someone elces transmitter this week to see if that is the problem.  I have a JR FM remote and it's still under warentee.  I'll have to send it in if I don't find a problem with my set up.
PJ, I got Towers new flyer in the mail last night and saw that item.  Looks handy and a good buy for $45.00.  I think that is what our club should have bought instead of this scanner.  Any one ever use a frequency counter in the past?  Looks like they would do a great job too.

Thanks for the help!

Dale P.

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I had the same exact problem with a brand new JR XS3 Pro at Walterboro this past weekend with one boat out of the 2 I was running. I did the walk away range check & could only get 15 feet before all my servos began glitching. Tried dialing in another frequency. Same reaction. I then removed the Failsafe from my throttle servo and everything went to perfectly normal so I ran without the failsafe all weekend with no glitches. My other boat has the same failsafe with no problems at all. Haven't had a chance to look into it any more since returning home. The Failsafe is a OFNA. I'll let you know if I come to a solution besides eliminating the Failsafe.

Scott Norris

Charlotte, NC

 

[piper_chuck]

The problem with my radio is range issues.  My fail safe keeps kicking in on the pond.  I tested the range on shore with the engine off and its does the same thing.  I can only get 20 feet away with the antenna down.  I tested all the batterys, switches, connections, changed to my back up reciever, etc.  But still have the same problem. 

Based on what Scott said about failsafes, I'd unplug the failsafe and try another range check. If this doesn't help, try a range test with a battery plugged directly into the receiver, one servo, and the receiver on the table top (non-metalic) with its antenna straight. If this works ok then there's something wrong with the way the receiver is installed. If it still doesn't work, the transmitter may have a problem.

 

[rcboatlover]

Thanks for the tips guys!

I agree that this Communications Reciever should be replaced with that frequency checker that Tower sells. That's really what out club needs. Something check for other radios in the area. Our pond is in the middle of a county park and it's not uncommon for people to run RC cars there.

As for my radio problems I have tried removing the fail safe, and changing crystals, but it still acts the same. I even switched to my back up reciever and wired the battery direct to the reciever and it still gave me problems.

I guess the only thing left to do is send it in for repair. Hopefully they don't take too long and keep my boat on dry dock. I will have to check E-Bay for a cheap transmitter to use in the mean time. I could use a back up any way.

Thanks again for the help!

Dale P.

 

[Mike G]

A lot of Failsafes (the add on kind) are built for 6 volts, if your running a BEC reciever the output to the servo is only 4.8 volts. I would think the OFNA one was built for 4.8v but check it to be sure. Some big servo's will draw enough power to kick the failsafe too. A lot of different variables to consider.