Radio problem
 

I bought a used Airtronics Quasar RD 6000. I had everything in the plane and set up, went to range test it worked then walked away. After about 10 feet no signal. Charged batteries before range test then recharged overnight then range test again same thing. Any ideas?

Thanks,
nathan

RE: Radio problem
 

You imply that it works OK when you are less than 10 feet away. This is quite weird because even a poorly tuned radio will generally work up to 30 or 50 feet away with the antenna collapsed. Remove and replace the crystals in both the transmitter and receiver. And check the transmitter battery voltage under load. Does the transmitter have a voltage display on it?

RE: Radio problem
 

Yes the radio has a voltage display. The first time i range test it the transmitter battery display said it was between 7 and 8. Second range test full charge

RE: Radio problem
 

CherokeeFlyer,
First of all, is it a Quasar or a RD6000? Those are actually 2 different types of radios. The RD6000 is the current 6 channel computer radio put out by Airtronics. The Quasar is one of the first 6 channel computer radios made by Airtronics and can actually be about 10 years old or so.

For your range problem. How is the receiver antenna routed? Is it fully extended away from the receiver, or is doubled up or balled up near the receiver? If this antenna wire isn't fully extended then your range can be reduced.

As Quinn said above, are the batteries for both the transmitter and receiver fully charged.

One word of warning about the crystals. DO NOT remove/replace the transmitter crystal. It is illegal in the US for the end user to change the transmitter crystal. This must be done in an authorized shop that has the equipment to properly tune the transmitter for the frequency it is on. You can replace the crystal in the receiver though.

If these issues do not resolve your problem you may want to consider sending the radio and receiver into Airtronics for service. The service center for Airtronics is top notch and they will go over your radio with a fine tooth comb to make sure it is working properly

Hope this helps

Ken

RE: Radio problem
 

I fully extended the receiver antenna the best i could, without getting tangled with the servos. Range did get a little bit better. The servos started twitching alot after the 10 feet, before i extended the receiver antenna and after.

RE: Radio problem
 

FYI _ when I suggested to remove and replace the crystal , I meant to just put the same crystals back in, not change the crystal to new ones. By doing this you are checking and cleaning the contacts from the crystal to their sockets. This is legal to do, but RCKen is right -- in the US, do not change crystals from one to a different one. Does the Transmitter battery read about 10 volts after a full charge? and after about 10 minutes of use, does it still read at least 9.6?

RE: Radio problem
 

CherokeeFlyer:

No matter what you do, the receiver antenna needs.. NEEDS to be fully extended. I may suggest you route the antenna outside the fuselage. See the picture as to how I handle that (and many, if not most other RC pilots do).

Another method I've used is to pass the antenna down to the bottom of the fuselage then run it along the bottom of the fuselage, securing it temporarilly with tape, then applying a covering to either offset the bottom of the fuselage color or to match the bottom of the fuselage color right over the antenna and iron it in place.

No matter what you do, you need to make sure it's full extended. If it gets 'tangled' with the servo's, use a short piece of plastic tubing, such as throttle guide tubing, to guide the antenna either away from the servo's or around the servo's. Then exit the fuselage in any method you choose (as I showed in the diagram or other method of your choice). Do NOT under any circumstances, put the antenna inside of a metal tube or container or allow it to ball up inside the fuselage. Make sure you secure the bitter end (the opposite end from the RX) with some sort of securing device.. a T-pin tied to a rubber band, whatever you choose but keep it from falling back into the fuselage and balling up on you.

Regarding the servo's jittering, that may happen with fully charged batteries, meaning peaked batteries, and may go away once you draw out a small amount of charge, say five minutes of operation, or when the transmitter is very close to the receiver.

DS.

RE: Radio problem
 

CG the diagram you showed is how I have it setup. I got the antenna on the side of the fuse getting passed the servos, then going out the back of the fuse/window.

RE: Radio problem
 

Then you are still having problems with servo jitter or inteference?

Try a range check making sure that the RX antenna is FULLY extended as shown in the diagrams I uploaded. You should be able to get about 100 feet or so away with the TX antenna down before losing the link. If you still have problems with the RX not working properly at close range, say 10 feet, then you may have either a TX or RX problem and suggest you send BOTH to the manufacturer and explain what you are seeing.

By the way, things to check: Is there any metal-to-metal contact on the throttle linkage? Are you using fully metal control rods from the servos to the rudder/elevator?

If metal-to-metal anywhere, especially at the engine, make that a metal to plastic or some non-conductive sort of linkage. If you are using metal rods from the servo to elevator/rudder, change that out to a metal to wood or use Sullivan Goldenrods or similar for control rearward. Any metal in parallel with the antenna can cause problems. The throttle vibration will definitely cause problems if it is metal to metal.

Check these things and let us know what you have.

Best of luck.

DS.

RE: Radio problem
 

all the connecters that attach to the rudder, elevator, and motor are all nylon. then on the servos i got E/Z connecters from Great Planes. The pushrods are metel, all is covered with plastic. Could it still be a problem all tho it is covered with plastic?

Nathan

RE: Radio problem
 

Yeah. The problem comes when there is metal next to metal next to an antenna. Any metal in parallel to an antenna can cause a degradation in the signal strength at the antenna. Metal, usually steel, is magnetic and absorbs electrical energy. It can also re-radiate which is another problem.

This may or may not be the cause, but when flying, you never know what will cause problems and it is best to minimize any potential for inteference or something that can (and will ) cause problems. Usually, it's sooner or later, but in your case, it may be sooner.

It may not fix the problem but it will certainly reduce the intensity of the problem if corrected.

The best thing you can do is make darned sure that there are no tangles in the antenna and fully extend it, meaning the full length of the antenna in as much of a straight line as possible. Then, remove any potential for metal-to metal contacts, worse case is the throttle linkage. Next comes the pushrods. Metal pushrods may or may not cause problems, but the potential for problems with metal pushrods is certainly there. After that, comes battery condition or radio condition.

Oh, this is fuel engine'ed plane right? I may not have asked that nor you may not have mentioned that.. it is not a gasoline powered engine, right? If it is gasoline powered.. well, that in itself causes probems with the ignition system causeing serious problems with the radio and must be dealt with separately.

Let us know what you find.

DS.

RE: Radio problem
 

No, I doubt that the connections are your problem if you're using nylon. It's really starting to sound like you have a bad radio. Pull the receiver completely out of the plane and check it again. By taking out the receiver you will eliminate any problems that might be caused by the plane. If the problems disappear then you'll have to start trying to figure out what in the plane is causing the problem. As was said above, you should be able to get about 100' away from the radio with the transmitter antenna collapsed and still have control of the servos. It's sounds like you're going to have to send it in for service. Use this link to get to Airtronics website and get the information you need when sending a radio in for service. [link]http://www.airtronics.net/company_information.htm[/link]

Hope this helps

Ken

RE: Radio problem
 

Hi Ken.

Yeah, that's what I was thinking, but wanted to try to go through the motions to clear any other issues if it's not a radio problem. He said that he has metal pushrods. Very remote, but could be a problem. Moreso if the problem was aerial (airborne) rather than trying to do a ground range check.

I think I suggested he have the radio checked too.

OK... later.

DS.

RE: Radio problem
 

Also make sure you haven't nicked or damaged the antenna wire somewhere along the way. If it accidentally got crushed or cut that could be a problem.

RE: Radio problem
 

As a long time RD6000 user I wonder if you have checked the set up on the transmitter. These transmitters can be set to FM, PCM, and positive or negative shift. Make sure that the tx is set for the receiver your using.
Fred

RE: Radio problem
 

Thanks for the help guys, but I'm at school right now can't check on the receiver. When i get home to check and look at the receiver, I'll tell ya what i find out.

thanks
Nathan

RE: Radio problem
 

To clear it up, the radio is a Quasar 6 channel. The plane is fuel powered.

RE: Radio problem
 

All good advice to you, Nathan. The antenna is a certain length out of the box. If shortened to satisfy a need, asthetics, and so on, that deminishes the capability of the antenna and will definitely reduce your range. Even if shortend a couple inches or so. I wrote up a short paragraph on wavelengh a while back explaining how it works and why, and why the antenna is the length it is. All this can come into play when you are having problems if, of course, you changed the length of the antenna either by accident or intentionally. It should be approximately 1.04 meters in length or right around 39.5 inches long.

Hope all this stuff helps, Nathan.

DS.

RE: Radio problem
 

The Quasar is an old transmitter. Where did you get it? (just wondering). But it should still work ok, but may require that you send it to Airtronics to get it serviced. Who knows how long it's been since it was serviced.

I have a Quasar, used it in England a few years ago (somewhat illegal because it was 72 MHz but they looked the other way). And, I was using it every weekend while I was over there and had no problems with it at all. I still have it, but don't use it any longer because I bought a newer RD8000 and now have the Spektrum DX7, which is, in my opinion, the Mercedes Benz of the RC radio world.

DS.

RE: Radio problem
 

i had a problem like that as well.....try concentrating on the crystals. i'll bet your problem is there. i changed my crystals and all was good once again. good luck

RE: Radio problem
 

Oh.. be very careful with crystals. DO NOT for any reason, play with the TX crystal. That is bad news, and is illegal to boot. The RX crystal, on the Quasar, may not be easily swappe with another one, but you may remove it and push it back in.

DS.

RE: Radio problem
 

Since you bought it used I'd be very suspicous of the system. Could be un-revealed crash damage. I recommend stopping at this point and sending EVERYTHING (not plane:D) to Airtronics for a check-up.

RE: Radio problem
 

CG,
The Quasar receiver crystal is a "universal" one. All of the Airtronics crystals for dual-conversion are the same. One from a brand new receiver purchased today will work in the Quasar receiver.

I have a Quasar that I still use today. It's a great radio that has given me absolutely no problems in the 9 years that I've had it, and is always rock solid.

Ken

RE: Radio problem
 

Thanks for the update, Ken. I've never looked at the Quasar RX so my comment was directed toward someone that has never done that before and that has not seen the Quasar RX crystal ( a person like me, for instance.. :D ). I do know about the RD6000/RD8000 RX crystal, as most of the Airtronics RX's (blue ones) are pretty much interchangeable except for servo capacity.

DS.

RE: Radio problem
 

Well Thank you for the advice about tx crystals change,
all need is a receive crystal in futaba reciver for my other plane.[X(]