I’ve been hunting for a good sync generator that can give me standard NTSC black, along with Trilevel sync for feeding HD. Videotek doesn’t have anything in that realm, Tektronix can do it for around $10k, but today I found Evertz. They make the 5600MSC, which does everything I need, plus can be synced against GPS and then feed an NTP signal out to the rest of your network. I’m waiting for a quote, but I believe it’s about half the cost of the Tektronix solution.
discretecosine.com
Leader is now making a low cost generator that has can be genlocked to your system and has 3 pairs of outputs capable of NTSC Black as well as Trilevel in various frames/freqs with 2 SDI outputs. The outputs are either HD or SD. This runs a list price of $6500. It is the LT4400.