15 Aug 2016

A fresh start with Channel Master 240

Submitted by drhans

After years suffering with Fortec Star 2.4m, I've finally moved on and got a new C-Band dish. It's a Channel Master prime-focus 2.4m dish with a polarmount. It is a very special setup because it's installed at a remote location due to the obstructed view in the place where I live. That means anything involving touching the dish would require me to drive approximately 50 kilometers, which could become quite expensive over the time and would piss off the wife too. The fact I don't have easy access to the dish takes some fun out of it but it also brings new challenges and new fun stuff to do. But more on that another time.

What I was hoping for when replacing the Fortecstar with Channel Master was easier setup thanks to the polarmount and better gain. And lucklilly I have to say both wishes came true. Due to a limited veiw, I'm only receiving 37.5°W to 47.5°W with this new dish, with future hopes of 55°W after chopping down couple of trees in the fall. Although this is only 10° span, with only 3 major satellites to receive, it's exactly what I aimed for.

Unfortunately everything gets quite complicated since 40°W and 47°W use circular polarization, while 43°W (and 55°W) are linear and since there is no real solution to this problem in the market, I have to live with a very unpleasant compromise of losing up to 2dB on circular signals due to the LNB being mounted 6-7 degrees off center. Luckilly such mounting of the LNB does not impact the linear signals, received by the in-focus LNB, coming from 43°W - and that was very important since 43°W is the weakest of all the western satellites and even a 1 dB loss would mean losing half of all the received transponders. In the future I will try to build a robotic solution which would allow me to maximize both linear and circular reception. But my hopes aren't very big - first tests suggest at least a 0.5dB loss on linear signals when a polarizer is added between the LNB and the feedring and such solution might prove to be too prone to failures requiring intervention, which is impossible in my case, since the dish is far away.

After boring you with all the limitations and future plans I think about before going to bed every day, here are my first impressions of this new setup. The very first impression was - shit, I should have gotten a bigger dish. Not only would I have saved money because I wouldn't have wasted hundreds of Euros on different LNBs, trying to get the best signal, but there would be quite more lockable transponders to get. But that's life, next time I will know better. It was also impossible to get a bigger than 2.4m dish with a polarmount for a reasonable price at that time and I didn't want to wait any longer. But my advice to anyone buying a 2.4m dish is to go bigger, 2.4m is nice for humble tests but will not be enough to receive weaker C-band stuff from 43°W and with the circular LNB being off-center, not even from 40°W and 47.5°W.

The FortecStar was just OK for a C-band beginner, the Channel Master is more than that. It's pretty good actually, the difference is significant but it's no miracle. It's likely that if a transponder was impossible to lock on the FortecStar, it will not lock on Channel Master either but if a TP was on the edge, or let's say up to 1dB below the edge, the Channel Master will help to get over the edge. Since my circular LNB is mounted off-center, I did not gain any channels at 40°W. But nothing was lost either. When I tried to receive 40°W with the in-focus central LNB, I was able to lock all transponders, including those not possible on the FortecStar (3980L, 3843L) and those on the edge were stable (3723L).