Well, this seems to be a popular line amp, seen it used a few times:
http://www.solidsignal.com/pview.asp?p=LA142A-T&d=Sonora-DBS-14-dB-Gain-Single-Ka%2FKu-Line-Amplifier-with-20V-1.2-Amp-Power-Supply-%28LA142aT%29
200' is the maximum recommended total distance between your LNBF and your receivers when using DPP equipment, I assume you are. You will need one amplifier per line to the LNBF, installed where you can plug it in to AC power so probably where the coax emerges from the conduit. The power is important, the problem you are having is more likely voltage drop than signal attenuation. This will be a complex operation, I suggest looking a little harder for a retailer.
http://www.solidsignal.com/pview.asp?p=LA142A-T&d=Sonora-DBS-14-dB-Gain-Single-Ka%2FKu-Line-Amplifier-with-20V-1.2-Amp-Power-Supply-%28LA142aT%29
200' is the maximum recommended total distance between your LNBF and your receivers when using DPP equipment, I assume you are. You will need one amplifier per line to the LNBF, installed where you can plug it in to AC power so probably where the coax emerges from the conduit. The power is important, the problem you are having is more likely voltage drop than signal attenuation. This will be a complex operation, I suggest looking a little harder for a retailer.