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Jun 01, 2009, 03:52 AM
Registered User
Quote:
Originally Posted by MoFl
kjetlei, to be sure, I'd measure the peak voltage, just to make sure it's 5V.

And, in this case, add a divider at the module's input. Just 2 10K resistors would do
MoFl, I have been following your posts. I made up your little circuit for checking the peak ppm voltage and on my JR the ppm peaks at 7.75v. I am using the divider as fitted in the turborix radio (R14 R49 R50). Do you think I need to change the resistor values in the divider to compensate for the higher ppm voltage? If so what do you suggest?
Last edited by com210; Jun 01, 2009 at 03:57 AM.
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Jun 01, 2009, 12:34 PM
Registered User
MoFl's Avatar
Hi, com210

You could change R14+R49 for a single 15 to 20K resistor.

I'm not sure about JR PPM spec but, from different posts (e.g this one), it might get to 8,5V or higher, so maybe 20k is better.

The measured 7,75V + 0,6V (diode drop) match well with the 8,5 V posted there.

With 20K from PPM and 10K to GND, you'd get 8,5*10/30=2,83V, under 3,3 V and still a bit higher than the 5*10/21=2,38V of the original design.
Jun 01, 2009, 12:46 PM
Registered User
MoFl's Avatar
It had been announced before, but now it seems like HK is going to have the Flysky "JR like" module soon:

http://www.hobbycity.com/hobbycity/f...&PID=9189#9189

They're also going to sell the 8 ch receiver.
Jun 01, 2009, 06:57 PM
Registered User
Thanks MoFl, I'll change those resistors today
Jun 01, 2009, 07:17 PM
Spritual Pilot
This question might be answered somewhere. Unfortunately, I couldn't find it.

How do you manage multiple models with mechanical trims with this radio. I wanted to buy this radio. However, this 'mechanical' trims keep confusing me. Are you re-trimming everytime when you fly a different model in the air?
Jun 01, 2009, 09:58 PM
Registered User
earlwb's Avatar
Yes you are retrimming each time you change models. Now I did notice that there are some subtrim option settings, so one may be able to trim the trim knobs back to center using the subtrim option settings. I didn't try it as of yet though.

I didn't have a problem retrimming as needed for different models.
It helps keep one's maiden flight skills fresh.
Jun 01, 2009, 10:40 PM
I enjoy the voices
Lead Wings's Avatar
Quote:
Originally Posted by MoFl
Hi, com210

You could change R14+R49 for a single 15 to 20K resistor.

I'm not sure about JR PPM spec but, from different posts (e.g this one), it might get to 8,5V or higher, so maybe 20k is better.

The measured 7,75V + 0,6V (diode drop) match well with the 8,5 V posted there.

With 20K from PPM and 10K to GND, you'd get 8,5*10/30=2,83V, under 3,3 V and still a bit higher than the 5*10/21=2,38V of the original design.
Thanks MoFl and com210 - I didn't manage to get near my shed on the weekend, but youve answered my questions re the JR PPM levels - and even worked out the resistors required! Time to hack next time I get a chance.....

PS - com210 thanks for the feedback on the performance of your system - sounds like your one bad crash was a faulty servo?
Jun 02, 2009, 03:44 PM
Registered User
keepitsimple's Avatar
Quote:
Originally Posted by jnyoun
This question might be answered somewhere. Unfortunately, I couldn't find it.

How do you manage multiple models with mechanical trims with this radio. I wanted to buy this radio. However, this 'mechanical' trims keep confusing me. Are you re-trimming everytime when you fly a different model in the air?

Leave the mechanical trims in their centerpositions.
Use an old (XP) laptop together with the configuration software to save individual aircraft settings.
Every time you change models , just load the model-specific settings from file and store them in the TX.
You migth use the mechanical trims for small corrections, but before saving settings try to set mechanical trims to centerposition and adjust with the programable subtrims.

There also is some software available for PPC and/or PPC2002.


regards from hans
Last edited by keepitsimple; Jun 02, 2009 at 03:50 PM.
Jun 02, 2009, 05:00 PM
Off 2 The Edge of Reality
TeamTEOR's Avatar
Does anyone know if there are any car TX radios like this in this price range?
Tom
Jun 02, 2009, 10:25 PM
I enjoy the voices
Lead Wings's Avatar

Using HK T4A as hack module for FM radios idiots guide


Ive consolidated info from this forum to create an idiot's guide to hacking FM radios to 2.4 GHz using the HK 4/6 channel / FlySky 2.4 GHz module as the donor and the to make it easier for the less electrickery savvy amongst us (me included).

To do this I've shamelessly plagiarised info posted by others Ė I have tried to give credit where due, but if you feel youíve been left out or donít want your stuff used then please tell me and Iíll edit/delete it.

Any corrections/updates/advice appreciated.
Jun 02, 2009, 11:21 PM
Registered User
JMP_blackfoot's Avatar
Quote:
Originally Posted by Lead Wings
[color=black]Any corrections/updates/advice appreciated.
Great job!
For using the 4channel transmitter as a simulator once the 2.4Ghz module has been removed, I suggest to run it off 4 cells only as I described in posts # 722, 726, 727 (page 49) and # 769, 772 (page 52).
(I have been flying both the 4-channel and the 6-channel transmitters off 4 cells without the least problem - 6-channel modification in posts # 783, 786 (page 53)).
Also, you could give the link to the simulator cable as found by MoFi :
http://www.dealextreme.com/details.d...603~r.12268550
Jun 02, 2009, 11:53 PM
Registered User
crucial's Avatar
I don't know if it makes a difference but I ordered this cable and it works.
http://www.dealextreme.com/details.dx/sku.11996

They look like the exact same thing.
Jun 03, 2009, 12:49 AM
I enjoy the voices
Lead Wings's Avatar
Quote:
Originally Posted by JMP_blackfoot
Great job!
For using the 4channel transmitter as a simulator once the 2.4Ghz module has been removed, I suggest to run it off 4 cells only as I described in posts # 722, 726, 727 (page 49) and # 769, 772 (page 52).
(I have been flying both the 4-channel and the 6-channel transmitters off 4 cells without the least problem - 6-channel modification in posts # 783, 786 (page 53)).
Also, you could give the link to the simulator cable as found by MoFi :
http://www.dealextreme.com/details.d...603~r.12268550
Thanks guys, I will add to the doc and re-post with any other input.

I have an old Wilkera sim cable at home - I haven't got around to trying it yet, but I know the plug is the same. Will try it eventually and post the results.
Jun 03, 2009, 09:46 AM
Curiouser and curiouser
Kokopeli's Avatar
Quote:
Originally Posted by Lead Wings
Ive consolidated info from this forum to create an idiot's guide to hacking FM radios to 2.4 GHz using the HK 4/6 channel / FlySky 2.4 GHz module as the donor and the to make it easier for the less electrickery savvy amongst us (me included).

To do this I've shamelessly plagiarised info posted by others Ė I have tried to give credit where due, but if you feel youíve been left out or donít want your stuff used then please tell me and Iíll edit/delete it.

Any corrections/updates/advice appreciated.
Lead Wings:
Your picture of the trainer jack on page 6 doesn't quite match my HK 4 ch radio.
Your pin#2 on my radio is a No Connection - not +5v
Your pin#3 on my radio is +battery output - not signal input

My radio matches this schematic (all though, with different pin numbers)
https://www.rcgroups.com/forums/atta...mentid=2535955

Your 6 ch turbo seems to be wired differently than my HK 4 ch.

Hope this helps.
Walt
Last edited by Kokopeli; Jun 03, 2009 at 09:53 AM.
Jun 03, 2009, 11:07 AM
anarchist
frac's Avatar
deleted....already answered


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