Old School Radios, giving another life into it.

[slow_jun]

Guys and Gels,

i know that this is old news but just want to share.

over the past 3 weeks, i've been googling on how to convert my Old KO- EX-II to 2.4 GHZ, and manage to give it a yank last night when my FRsky 2.4GHZ DIY kit arrive from Hobby King (Hong Kong service was Bad), so below are some pics on how to hack your Old Ko -EXII (Same IC used by EX- 5 ) using the Oki chip pin 9.

You will be needing the parts below;

FRsky 2.4 DIY kit. $15.80/pc.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14353

Some 2.4Ghz RX (pretty small and light). bought 2 pcs for $14.74 /pc.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14352

Locate your TX PPM signal , for KO (Oki chip L9362).

Schematic Diagram of the chip.



EX- II PPM signal pin ( Pin 9)





EX- 5 PPM signal pin ( Pin 9)



I converted first my EX- II and tapped from the IC's Pin 9 before the Resistor. PPM signal would be on the right with the diode attached to it, the right would be the negative (-)





I tapped the Positive (+) power source directly after the on-off switch, when i tried using the source coming from the board, it did not worked, i think the power is not sufficient enough to power the module ( it does says that operating voltage is 6V-13V ).



All wires are in place.



Binding button in place.



Finish product.





Haven't tried to check the range yet but will do once i get the time. Over all, binding was fast, i think much faster than my M11 RX 441 rx ;-( , but still need to thorough test it.

Over all its a cheap way to re-use your old TX and give it another life. , as compared to the Corona Hack (based from some feedback) the Corona module DIY has problems on the overheating of the DIY due to the chip PPM signal cannot handle voltage above 3V whick FRsky solved by putting a Diode to filter voltage above 3V, and FRsky (claimed) that the ACCST is much faster (some reviews proves it , RCmodelreviews via youtube), than other 2.4 GHZ (Corono, Assan in particular).

This only shows how to do it and will not guarantee that it will work for all hacks, users are advise that risks is involved and potential equipment damage may occur if installation is not correct.

I encourage all potential "Hackers" to do first their homework prior performing this trick so that no regrets in the end, there are some reported issues like servo jitters (mine was very minimal but tolerable) and some does not have any, so one should take these into consideration before doing and buying these DIY. I try to be as honest as possible and share all the details on how to do this Hack and will try to help as much as i can. so lets enjoy again our old school radios and race!!!!!!

cheers!!!

jun.

[tamiyadan]

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[slow_jun]

Sorry dont have a fet servo,had one before.

Some analog servo are not affected by the servo chatter,but what brand and make im not sure,there Are some thread at rcgroups and rcmodel reviews that identifies which was tackled. But the chatter are not experienced by some, and there was a fix whch addressed this issue. Anyway a good research is always helpfull before hacking your precious vintage radios.

[aeiou]

Interesting write up. It looks like a fun project - kind of reminds me of my Heathkit/Radio Shack projects from years ago. I might have to try this with my old XL2P to go along with the old-new theme. I wonder if I find a LiPo pack to fit that'll old radio?

[tamiyadan]

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[aeiou]

just remember the conversion is for the transmitter, you will need to use a new receiver.

if you really want to keep that stock look you can pack a new spectrum receiver into a old futaba or airtronics case.

Yep, the XL2P is a transmitter.

[slow_jun]

Guys,

im experiencing a little jitter on my servo, you may want on to hold and wait till Hoby king releases the two way telemetry module which other sites says that is solves the servo problem, analog servo is not affected, but tyr your luck.

thanks.

[Bormac]

I have a few EX-5 and a single EX-9 radio. I dont mind the AM function but wouldn't mind having a go at setting atleast one up with 2.4g.

[RC104ever]

Wow I am continually amazed at the things that you guys can come up with on this board. I would never have even dreamed that something like this would be possible. Guess I'm just not that imaginative

[slow_jun]

Just to update this thread, HK has released the DIY with telemetry that solved the jittering issue. post your Hacks here....

DIY With Telemetry

http://www.hobbyking.com/hobbyking/store/__17205__FrSky_DHT_8ch_DIY_Telemetry_Compatible_Transmitter_Module.html

RX With Telemetry

http://www.hobbyking.com/hobbyking/store/__24788__FrSky_D4R_II_4ch_2_4Ghz_ACCST_Receiver_w_telemetry_.html

[knixdad]

I have so many Magnum Juniors laying around. Definitely something to mess around with during the snows.

[JK Racing]

slow_jun, are all the OKI L9362 chips the same? My XL2P has the same chip, looks a touch different, but same numbers and its 14 pin as well. I am attempting to use a hack kit, but it wont power up without signal (testing pin 9). I tested it on another radio I hacked, it powered up fine, I checked + & -, we are good and have plenty of juice.

[slow_jun]

They should be the same if the part number is.make sire your hitting the same pin,pin one should start top left(where the notch is placed) then count downwards then down-top-. If your not able to power it on maybe (just maybe) you did not get the power right.

or...

did you tap your power from the boards? in my previous post, I believe I also encountered that issue, to overcome that one, I directly taped from the + on off switch.

note that operating voltage is from 6V-13V.

or if you need to tap before the resistor ( Signal on Pin 9), for it to work.

let us know the outcome.

[JK Racing]

After many hours of excruciating research, I found the OrangeRX diy kit is for DSM2/DSMX air, not ground I gave up on the XL2P and kept trying to just get the darn thing to bind using my Futaba that has my FrSky diy installed. I will spend today putting that kit back in the Futaba.

What a waste of a Saturday. Not a happy camper.

[JK Racing]

I get no signal on pin 9, but i do on pin 8. At least my hack kit says I'm getting signal. I can bind the receiver, but nothing works. I pull the hack out, plug in the crystal, everything works fine, put the hack back in, binds up, no movement. I'm stumped. FrSky diy, the orangerx is back in the box for now.