Joined: 06 Feb 2012
Posts: 5
Location: Coffs Harbour
Testing a 27 mhz remote
Hi.
Just wondering if anyone could help me out. I have a remote cointrole K9 from doctor who. It's a bit of a collectors item now and I just bought it 2nd hand. For some reason the K9 robot is not responding to the remote or the remote is not transmitting. I don't know which is which. I also have no experience in RC but was wondering if there was a way to test if the remote was transmitting to find out where the problem is.
Checked the control out and all the wires are clean and connected.
Any help would be greatly appreciated.
Thanks
Bidge
Mon Feb 06, 2012 3:58 pm
dyrodium Experienced Roboteer
Joined: 24 Aug 2004
Posts: 6476
Location: Sydney
Hey there,
27mhz AM systems require a crystal to tune the transmitter into the reciever, they're little removable silver things with two prongs. If you can locate them they have to have exactly the same number on them to work. They can also break so might need replacing. Do you get any kind of power light on the transmitter or reciever in the k9? A photo would be really helpful here!
In this day and age replacing the controller with a newer 2.4ghz system would be a great idea, it will help prevent your machine twitching and running away due to loss of signal and give much smoother control.
Mon Feb 06, 2012 4:43 pm
bidgeeman
Joined: 06 Feb 2012
Posts: 5
Location: Coffs Harbour
Hi. Many thanks for your reply.
Here are two images of the actual unit.
(Images removed issue solved)
I did notice a silver oblong looking thing under the circuit board on the opposite side as the general components when I pulled it apart. Also there apears to be no light on the rc unit at all.....the buttons on the front look like lights but are holes where the buttons should go. When I had the unit pulled apart my wife fiddled with the plastic buttons that were moulded onto a stem and she broke off the last button so I left it out till I fix it. The buttons can be depressed using a p[encil poking down through the hole.
Cheers
Bidge
Last edited by bidgeeman on Mon Feb 13, 2012 6:57 pm; edited 2 times in total
Mon Feb 06, 2012 5:14 pm
seanet1310
Joined: 08 Nov 2006
Posts: 1265
Location: Adelaide
This is a put in battery and go kinda devence so it is unlikely the crystal will be highly user serviceable (under an easy to undo panel or even just a slot). Chances are the crystal will be under the casing somewhere on the PCB. May or may not be removable.
If you have an oscilloscope you could check signals to the antenna and on the dogs side.
Any chance you have photos of it pulled apart ? Would be far more helpful then generic grey case _________________ Remember to trust me, I am an Engineer.
Joined: 06 Feb 2012
Posts: 5
Location: Coffs Harbour
Hi. I just pulled his remote unit apart again and took these pics for you.
(Images removed issue solved)
I think the silver thing at the bottom of the board is the crystal you are talking about. It's a bit hard to get the board off it's mounts as the wires are so short I would have to cut them to flip the unit over and I am not much of a solderer
Hope you can help.
Cheers
Bidge
Last edited by bidgeeman on Mon Feb 13, 2012 6:57 pm; edited 1 time in total
Hmmm yeh it looks to be a self contained unit with a single IC under your black goop and while the crystal may be damaged its hard to tell unless you give it to someone who can test it properly.
Did you want to maintain the original electronics as if you want I could probably assist in reverse engineering the controls and replacing it with a modern Tx/Rx combo. Although this may require a complete rewiring of the K9 unit as well. _________________ Steven Martin
Twisted Constructions
http://www.botbitz.com
Mon Feb 06, 2012 8:21 pm
seanet1310
Joined: 08 Nov 2006
Posts: 1265
Location: Adelaide
Yea, Like steve said that looks to be the crystal and everything else of importance for processing is in an Integrated Circuit protected by the black blob.
Are you sure it is the TX at fault and not the RX in the k9? If you are confident at soldering and can find a crystal with the exact frequency you could replace it and see if that fixes the problem _________________ Remember to trust me, I am an Engineer.
Joined: 06 Feb 2012
Posts: 5
Location: Coffs Harbour
I have another working remote arriving at the end of the week so will try that. Also found out that the ariel for the unit is in the tail and if the wire comes off (from being twisted as it's rubber) the wire can come off the board in the unit.
Thanks for the responses
fingers crossed.
Cheers
Bidge
Wed Feb 08, 2012 7:00 pm
DumHed Experienced Roboteer
Joined: 29 Jun 2004
Posts: 1219
Location: Sydney
quote:Originally posted by marto:
Although this may require a complete rewiring of the K9 unit as well.
I don't think you can do that if you're not a timelord _________________ The Engine Whisperer
- fixer of things
Give me another year and then you can start referring to me as "The Doctor" _________________ Steven Martin
Twisted Constructions
http://www.botbitz.com
Wed Feb 08, 2012 9:11 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
sound more like the master to me ;-P _________________ Mechanical engineers build weapons, civil engineers build targets
Fri Feb 10, 2012 9:19 am
bidgeeman
Joined: 06 Feb 2012
Posts: 5
Location: Coffs Harbour
Hi All.
Just an update. New remote arrived today and the unit worked. It was the remote that was faulty.
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