Sounds like a nice signal generator with all the features you need for proper alignment.
Yes, it is. It'll even do RDS which is something I'll probably never deal with. Most of the things I have pre-date RDS except for the MP3 players with FM radios. But, those are disposable since there isn't anything that can be tweaked.
I worked as a Chief Engineer for the FM portion of an AM/FM outlet in York Pennsylvania. The studio site used Orban and Time Frequency Technology gear to get the signal up to the mountain. On the mountaintop we had a 5kw CCA transmitter for hot standby and a 20kw CSI running 11kw into the feedline with about 6kw arriving at the antenna for 50kw ERP. The tower was 400+ feet from the transmitter building and the antenna was 820 feet up. I would tune the transmitter for a flat bandpass to remove as much AM component as possible. This was not the most efficient operating point because things were not at their peak of resonance. CSI data registered with the FCC claimed 73% efficiency but we seldom got better than 69-70%. The exciter was a BE20 if I remember correctly. The IPA was the 5CX1500 with the A version and the B version used but they were all crap!! Prone to all kinds of failures and short life. The emission would start to drop rapidly at about 8 months even with careful use of filament voltage control. They were also prone to silver migration along the ceramic between the plate and grounded G3 ring which lead to arcing and the ceramic cracking. Probably the worst design from Eimac ever with the possible exception of the 'more expensive than gold' 4CX600 series (JA, JB) built for the military at military pricing!!
Oh man, you really worked with some high powered stuff! The most I ever see is 300W coming out of a Drake or Swan transceiver at work as a radio tech. Your experiences has brought back some memories as a young ME packaging antenna farms on satellites. It was all about getting maximum EIRP on the ground. Everything from optimizing the locations of the TWT's and SSPA's on the payload to squeezing the largest antenna on a volume constrained spacecraft. The technical challenges sure made it an interesting job.
So you have 11kw coming out of the CSI and 6kw arriving at the antenna. Were these ohmic losses in the transmission line?
On the output tubes, at least you can bring down the transmitter and replace them. We had a similar situation where tin was in our supply line. The tin would develop whiskers. This shorted out several of our satellites crippled or dead. The first instance was a PanAmSat and it brought down telecom across CONUS. The day the earth stood still for us.