Lemon and FrSky Hack module queries

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wookman
Posts: 37
Joined: 09 Jun 2021, 16:06

Lemon and FrSky Hack module queries

Post by wookman »

Aerial SMA / RP-SMA Notes:
Also whilst on the topic of module connections and extension leads, note that there are two standards for the aerial connection and its vital that your module, aerial and any extension cable all match up. Two pins obviously wont fit together, but two females will appear to fit but will not connect.
For example a Spektrum or Frsky aerial will appear to fit an Orangerx module perfectly.
But there will be no connectiom of the centre pin!

OrangeRx, Assan and Quanum are SMA.
Spektrum, Frsky & Corona are all RP-SMA. If in doubt, check the location of the central pin.



Where does the Lemon module fit into the above?
If it is SMA could you change it by plugging in an FrSky Coax to the Lemon module?


The FrSky V8 hack module I have salvaged from a sorry looking JR 3810 was wired with what I think is a small diode in the ppm cable. Anybody any idea why? Do I need to replicate that when I put it in the MC24.

I am planning to put the FrSky and a Lemon hack into the MC24 as it is a lovely Tx to use and I have loads of receivers I could use. Should I set it up to switch between each module or run both 2.4Ghz together? I am thinking reduce the number of potentially unreliable switches.

All answers, even rude ones, gratefully received.
You can't have too many gliders. You can have too little time.
jmendoza
Posts: 167
Joined: 18 Feb 2018, 23:07

Re: Lemon and FrSky Hack module queries

Post by jmendoza »

The Lemon Tx DIY module is DSMP protocol, which works with Lemon receivers, and any other DSM2/X receivers, such as Spektrum, and Orange.

It is strictly PPM unless you have an ERSky transmitter. It's main purpose is for use in converting old transmitters to 2.4 GHz .
$38.00 US, plus shipping.
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stuart mackay
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Location: Swaffham, Norfolk
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Re: Lemon and FrSky Hack module queries

Post by stuart mackay »

wookman wrote: 25 Jun 2021, 21:31 Aerial SMA / RP-SMA Notes:
Also whilst on the topic of module connections and extension leads, note that there are two standards for the aerial connection and its vital that your module, aerial and any extension cable all match up. Two pins obviously wont fit together, but two females will appear to fit but will not connect.
For example a Spektrum or Frsky aerial will appear to fit an Orangerx module perfectly.
But there will be no connectiom of the centre pin!

OrangeRx, Assan and Quanum are SMA.
Spektrum, Frsky & Corona are all RP-SMA. If in doubt, check the location of the central pin.



Where does the Lemon module fit into the above?
If it is SMA could you change it by plugging in an FrSky Coax to the Lemon module?


The FrSky V8 hack module I have salvaged from a sorry looking JR 3810 was wired with what I think is a small diode in the ppm cable. Anybody any idea why? Do I need to replicate that when I put it in the MC24.

I am planning to put the FrSky and a Lemon hack into the MC24 as it is a lovely Tx to use and I have loads of receivers I could use. Should I set it up to switch between each module or run both 2.4Ghz together? I am thinking reduce the number of potentially unreliable switches.

All answers, even rude ones, gratefully received.
Lemon and Spektrum have the same antenna polarity
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Mike_K
Posts: 669
Joined: 16 Feb 2018, 06:35
Location: Hertfordshire

Re: Lemon and FrSky Hack module queries

Post by Mike_K »

wookman wrote: 25 Jun 2021, 21:31
Where does the Lemon module fit into the above?
If it is SMA could you change it by plugging in an FrSky Coax to the Lemon module?
Stuart is quite correct, the LemonRx is the same as a Spektrum
wookman wrote: 25 Jun 2021, 21:31
The FrSky V8 hack module I have salvaged from a sorry looking JR 3810 was wired with what I think is a small diode in the ppm cable. Anybody any idea why? Do I need to replicate that when I put it in the MC24.
The microprocessor used in the V8 hack runs at 3.3V and there were quite a few failures of the early V8 modules because the ppm input was getting damaged by the 5V ppm signal (or higher on some older transmitters). The Schottky diode switches to 0V, when an encoder ppm goes positive it doesn't conduct, but the V8 hack microprocessor has an internal pull-up resistor to 3.3V, so it still see's logic 0 and 1 correctly. I think Phil_G was one of the first to suggest this modification. So yes, if you plan to re-use the V8 hack module, the schottky diode needs to be fitted. Later V8, DHT and XHT have the diode fitted on the circuit board.
wookman wrote: 25 Jun 2021, 21:31
I am planning to put the FrSky and a Lemon hack into the MC24 as it is a lovely Tx to use and I have loads of receivers I could use. Should I set it up to switch between each module or run both 2.4Ghz together? I am thinking reduce the number of potentially unreliable switches.

All answers, even rude ones, gratefully received.
I've never tried running two modules, I'll let somebody else answer that one!

Mike
wookman
Posts: 37
Joined: 09 Jun 2021, 16:06

Re: Lemon and FrSky Hack module queries

Post by wookman »

Thanks for the steer on the diode with the V8. I will salvage that too.
New plan is to have swappable (is that a proper word) modules with the the V8 and the Lemon built into redundant JR 35Mhz module casings.

Still not sure about the aerial situation but I suspect a bit of experimentation will provide answers.
You can't have too many gliders. You can have too little time.
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