I am building a Kadet LT 40 and Im on a tight budget. A friend at the field had an Alpha that he crashed last fall. Crash was pilot error as he was learning and confused his controls.[:@] He bought a new RTF Alpha and said he would sell me all of the radio equipment out of the dead plane for cheap. Anyways, I took everything home to check it out before buying it and it didnt work. Read that the Xtal can be damaged in a crash so I took everything to the LHS and we put a new Xtal in. Whallaaaa! It works. All the servos feel smooth. I am going to open each servo and inspect gears visually for damage. If all is good, then I am thinking about purchasing it from him. Radio is a JR Quatro and servos are JR 527's. So, the question is, Is there anything that I should be wary about with a radio setup that has been in a crash? I know that they recommend sending in radio equipment after a crash but is that just to ensure that the radio didn't cause the crash?

Thanks all,

Shaun

Is you initial failure due possibly to a low/dead battery? Most likely the only serious damage could be in the RX or possibly the servos. Range check the setup and check each servo. If you arn't satisfied with the the RX, send it in to be checked including the crystal.
If you check everything out and are satisfied, spend like you are going to replace the RX.......

good advise! .. only thing diff i would do is just buy the servos.. dont worry bout the rx buy a new one

In all my years of flying I have had a great number of planes crash due to radio failure. I have never had one crash due to a cyrstal failure nor have I heard of one. I am sure that it can and has happened, although I would not put it on the top of my list to be damaged in a crash. I would highly recomend that you or the orignal owner send the radio back to JR for a check up. I know that this cost's money, however it could prevent an even more expensive crash. Work out a deal with the seller to see if you can split the cost's. Hope this helps, Dave.

His crash was due to pilot error. He got disoriented and spiralled it in. I already have a Futaba 6XAS radio. A new reciever and Xtal for my Futaba radio is going to cost around $60. I can get his whole JR setup for about $30.

All the servos + rx. + battery for $30? Go for it! Servos alone are worth that much!

Jerry

Something to consider. The Futaba and JR systems have the battery polaritys opposite from each other. A student of mine had both and was having problems blowing fuses because he would plug in a futaba charger cord into a JR or vice versa. That really messes up a day at the field. He eventually went with JR and sold the other gear. Decide which format you like and stick with that one. Now starts the whos best argument. For the average flyer, they are all good in my opinion. Also, I heard of a guy test a rec by rubber banding it to an orbital sander for a vibration test. It worked. But sounds like it could be a destructive test to me. He had a big chunk of foam rubber between the rec and the orbital surface.
Edwin

Here is my 2 cents worth. Go ahaead and buy it. I would think about ending the reciever in to be checked. Just checking it shouldn't cost more than 20 bucks. Or just go ahaead and buy a new Hitec reciever. The new one will cost about 60 bucks with chrystal and S&H. If you finally end up with a computer radio you will already have at least one spare reciever. Anyhow a test can be done with an electric engraver with a pencil eraser attatched. Use the engraver to vibrate the case of the reciever. And check the servo's (which are hooked up and powered up) for jitters or random movements. These are sighns of reciever damage. You should also check the switch. They can be damaged as well. Bottom line ya pays your money and ya takes your chances. I feel you should be ok with this used radio.

Mark Shuman

Shaun,
I believe the last poster Phread has it right. Use a vibration source on the repaired receiver. Have your buddy tapping on the receiver with a pencil and do a range check with the transmitter antenna down. You should get at least 60' distance.

Check the servos by holding some tension on the arms while another person operates the transmitter. They should still operate smoothly, or take them apart and visibly check the gears. I'd do both.

Wiggle the on - off switch to make sure it has no glithches. Test this by plugging in a small 6 volt lamp (#47) into a spare servo socket. Just use just the red and black wires. You should not see any flickering.

The receiver does not have to be in the plane to do the testing. Just make sure the antenna wire is fairly straight and not coiled up.

Good luck.
John