You guys just cannot see the difference between a receive only system and a transmit and receive system. This has nothing to do with your ability to chop glass. The FCC was very reluctant to allow technicians with only one day training to install transmitting systems. The FCC is closely monitoring the issue of improperly aligned VSAT systems. If a problem develops and it is determined to be a result of improperly installed VSAT systems, the FCC may require a far more stringent certification and licensing path for this industry. Every time a VSAT system is improperly aligned, it has the potential to interfere with other satellites, and the users who use them.
Making a home made feed horn boom and tinkering around with the focal length creates all sorts of side lobe issues. You may very well find a focal length that gives you maximum signal strength, and cross pol, but creates undesirable side lobes on the transmit side. These side lobes will affect other people.
For the record, in 1983 I was 21 and was working for a company that manufactured 10' and 12' fiberglass dishes. I chopped at least 100 dishes before I moved to installation later that year. Working with that company I helped engineer two more dishes with lower F/D ratios for maximum TI suppression (We had a lot in the South Seattle area).
I have been a field technician in the TVRO business for over 25 years. I started working with Hughes products back in the DirecPC days where you installed an ISA card the size of a Buick in the PC. I am HughesNet certified, WildBlue certified, Starband certified, Galileo certified, IDirect trained and I installed hundreds of DX systems in Seattle, WA for residential and SMATV systems (Nice stuff, way ahead of their times)
This is not about knowledge or skills. This issue is about doing the right thing. Tinkering around with a transmit system whereas you may be interfering with other users is wrong. Get the right equipment and pay a certified installer to align the dish. If you cannot find an installer, then at least learn the proper method of cross pol alignment.