LP5DSM Tx

[Paul Newell 2]

Has anyone used a trainer lead on the LP5DSM TXs that came with the Blade CX2 Helicopters.

It is a FOUR way 3.5mm jack similar to used by some audio visual equipment.

There are various forum postings elsewhere that relate to using one LP5DSM with say Spektrum or simulators. These do involve special connections.

My problem is that a proper 4 way lead with one to one connections does not function. The Trainer switches do not switch control.

I have verified (internally in the TX) that the lead is making proper electrical connection in the jack sockets and that there are no shorts between the 4 poles.

As far as I can determine the jack has the following signals.

Tip - negative going ppm signal

Ring 1 - Power positive

Ring 2 - ?????

Sleeve - Power negative.

A web search suggests the Ring 2 is an encoded signal that should provide the trainer signal between the LP5DSM TXs and that it does not use the more normal method of ppm handover. Electrically it certainly looks like a semiconductor device input connection. However it does not seem to show any form of data.

Just a warning - don't go plugging a mono or stereo 3.5 mm jack into the socket as there is a risk of shorting power positive and negative.

[Paul Newell 2]

Issue resolved

Contrary to the information gleaned from the web search, the system does use ppm transfer.

Ring 2 is an input that accepts the ppm signal form the other transmitter.

The cable requires a crossover so that tip connects to Ring 2 in both directions.

This does not seem to correspond to any available Audio Visual cables. However there is a special E Flite cable which is not mentioned in any documentation for the transmitters and proved elusive in any web search until the part number EFLH1059 was known.