So I need to wirelessly send a feed from my Tascam DR100 mkii into camera via a set of Sennheiser G3s. Am I right in thinking that as the output of the DR100 is a 3.5mm stereo LINE level, I will need to convert the signal to MIC level to go into the G3 transmitter? If so, can anyone recommend the right cable for the job?

Thanks.

The Sk100 G3 transmitter is perfectly capable of receiving a line level signal, there's no need for a conversion to a mic level.

You will however need a line input cable that is not supplied in the kit (you can make one yourself).

The pinout is on the page 32 of the transmitter's manual.

The tip is connected to the sleeve of the 3.5mm TRS connector and they're both tied to the ground and connected to pin 1 on the XLR connector. The ring carries a positive line level signal and is connected to the pin no.2 on the XLR.

I seem to recall that the sennheiser G2 and G3 system can be unbalanced line or mic input depending on which connector is connected on the TRS 3.5mm jack.

Tip = mic.
Ring = line
Sleeve = screen

So to get both left and right outputs from your tascam you will need a stereo 3.5mm jack to a 3.5mm stereo jack with just the sleeve and ring connected.

3.5mm stereo from tascam

Tip = left
ring = right
Sleeve = screen

3.5mm stereo jack G2/3

Ring: Left+right +ve
Sleeve: screen (tip connected to ground)

great, thanks guys.

So would this cable do the trick?
Sennheiser CL 2 (CL2) Balanced XLR line input cable for G2 pocket transmitters, 1.5m length (p/n 04840) (http://cvp.com/index.php?t=product/sennheiser_cl2)

Obviously the xlr end would have to connect to a xlr to 3.5mm converter to go into the DR100, but that should work right?

Yes it would work but bear in mind you are going from a stereo 3.5mm output to a mono XLR input so you may not get both output channels so check you stereo to mono adaptor.

The outputs on the DR100 are 'line level', you need a cable wired as Gary stated.
L+R (or L or R. if mono) from the Tascam's 3.5mm connector to the 'Ring' terminal of the Sennheiser SK100 bodypack transmitter. The 'Tip' terminal on the transmitter end must be tied to the shield terminal only.
You could use an attenuated cable to feed the transmitter mic level but the bias current (mic power) could be a noise issue without a blocking capacitor.
You're probably familiar with the receiver> camera connection already.

Thank you guys. Still a little unsure of exactly what I'm looking for. Is there a certain cable I can buy online to do this? I'm no good at making cables so if I can order one, that would be most helpful!

I 'think' the optional Sennheiser "CL-2" line-in cable would work. (XLR-F to 3.5mm). but you would still need an additional adapter to go from stereo 3.5mm to XLR-M.
I would recommend finding a pro audio tech person or pro audio shop to make one.
Soundkit ( http://www.soundkit.co.uk/ ) could most likely make or recommend something that will work.

Ok thanks a lot for all your help, much appreciated!