Hi Tim,
I have the 1296 tvtr from SGLAB. when setting it up i use a light camera tripod and i have a 4 el yagi that a [SK] friend made. The transverter would ideally be mounted on the tripod too, to reduce cable losses on 1296 to reduce cable loss. For the IF, cable loss can be compensated when setting the rx gain and rf sensing trigger level on tx. Use the same cable you intend to use in the field when making those settings. So the loss in the IF cable, though small, is immaterial.
My setup still has a metre of RG58 on 1296 and that is the main loss in my setup. The use of a longer yagi with the transverter mounted on the rear end of the boom is a better system.
Increasing antenna size from 4 el to 8el is only 3db more gain at most.
Re the proximity of the operator to the antenna, see Enter parameters - RF Exposure Calculator - VP9KF/Hintlink. Note the correction factor for average power. Recalculate for 25w if you use the add-on amplifier.
That site is linked to by the arrl site.
There is another EMR calculator for windows computers which can be downloaded from the WIA website. The software was developed by Doug VK3UM (SK).
73 Andrew VK1DA/VK2UH