Change Cox 3-1 machine frequency
10-18-2003, 08:20 AM
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Change Cox 3-1 machine frequency
I recently purchase 2 of these "Magic Machine" 3-1 toys for my 2 boys. Since Dad flys real planes, I thought a toy like this would be perfect to introduce them to flight, as well as electronics.
When the two boxes arrived, i found that both are on the same freq. No biggie, I purchased a set of RC crystals for channel 3, both toys are channel 4 now. Since I have a fair amount of experiance with souldering, I figured I could swap out the crystals in one of the toys, and they could play at the same time.
Well, the Tx crystal was a sinch to swap out. However, i pulled the circuit board from the toy and do not see a Rx crystal anywhere on the board. a few resistors, diodes, antenna, and an IC which reads RX-2B J3B81. The board is a HY-009c.
Anybody have a schematic for this, or can give some advise?
Thanx!!
Kevin
When the two boxes arrived, i found that both are on the same freq. No biggie, I purchased a set of RC crystals for channel 3, both toys are channel 4 now. Since I have a fair amount of experiance with souldering, I figured I could swap out the crystals in one of the toys, and they could play at the same time.
Well, the Tx crystal was a sinch to swap out. However, i pulled the circuit board from the toy and do not see a Rx crystal anywhere on the board. a few resistors, diodes, antenna, and an IC which reads RX-2B J3B81. The board is a HY-009c.
Anybody have a schematic for this, or can give some advise?
Thanx!!
Kevin
10-18-2003, 10:52 AM
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RE: Change Cox 3-1 machine frequency
Anybody have a schematic for this, or can give some advise?
The only way to effectively fly two of those models at the same time is to have one on 27Mhz and the other on 49Mhz. Sadly, moving a 27Mhz rig to 49Mhz (and vice versa)would require substantial modifications to the Tx and Rx.
10-18-2003, 11:23 AM
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RE: Change Cox 3-1 machine frequency
OK, now i have 2 other RC planes, one is channel 6, one is channel 5, the 3-in-1 toy is channel 4, and they all work corretly, around each other, with seemingly no interferance between each other.
So, it makes sense if i change the second unit to a channel 3 devise, it would work. What about completey changing out the receiver board with a cheap-ohh rc plane board that is channel 3?
Kevin
So, it makes sense if i change the second unit to a channel 3 devise, it would work. What about completey changing out the receiver board with a cheap-ohh rc plane board that is channel 3?
Kevin
10-18-2003, 12:11 PM
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RE: Change Cox 3-1 machine frequency
That is interesting. What are the frequencies marked on each Tx Xtal?
The RX-2B IC's operating frequency is set by the coil near the antenna. The coil's slug must be adjusted with a non-metallic wand. Be careful with the adjustment -- make sure the Rx is stable over all operating temperatures and voltages after you are done.
More info on the RX-2B can be found on my Micro-Size R/C Plane web page: http://www.rc-cam.com/microszr.htm
RC-CAM
The RX-2B IC's operating frequency is set by the coil near the antenna. The coil's slug must be adjusted with a non-metallic wand. Be careful with the adjustment -- make sure the Rx is stable over all operating temperatures and voltages after you are done.
More info on the RX-2B can be found on my Micro-Size R/C Plane web page: http://www.rc-cam.com/microszr.htm
RC-CAM
