Overview of a Television Transmitter

This was my very first video I made for TheOLE, only there was no TheOLE back in 2009. I just took my camcorder and ran up to the transmitter and shot the footage and then put it all together. To make my self sound more broadcast like I lowered my voice but my wife said I sounded like an undertaker, so I never did that again.

[@nakayle]

Thanks for the reply OnLineEngineer. Some 40 years ago I maintained a RCA TTU-30A. Back then they used Klystrons rather than IOTs and lots of tubes- even the exciter was tube based. I've been out of broadcasting many years but I still find it interesting and try to keep up the many changes. I will check out your other videos and appreciate you posting them.

[@BurtBartlow]

For some reason after watching this video I am craving Olive Garden.

[@vbruiz3999]

thank you so much for this, it is well.

[@phillysonthehill]

Great video thank you

[@TheOnLineEngineer]

To cover the same area you need about the same power when operating on or near the same frequency. They measure power differently, analog measures peak power and digital measures avg power, so it looks different when its really the same. The analog put out 30KW peak and the digital 19KW Avg but thats actually a lot more power than the analog.

[@TheOnLineEngineer]

I'm glad you liked it.

[@antronx7]

Thanks, that is clear to me now.

[@leehewitt9559]

Very interesting

[@TheOnLineEngineer]

Its a lot, an MSDC IOT Transmitter can consume 80,000 Watts per hour and up. The MSDC is the most efficient high power UHF transmitter there is and that 80KW of power is needed to make 30KW RF power. Now during the transition period each station ran both an analog and Digital transmitter, so when we shut down the analog transmitters power consumption was cut in half.

[@antronx7]

Thanks for your reply. Does that mean that both analog and digital transmitter use about equal amount of AC power and have about equal RF output? I was under impression that only about 5% of digital transmitter RF power output is needed (relatively to analog) for same area coverage as analog. How much RF power did your old analog transmitter run? Thanks.

[@antronx7]

How much is the total electrical power load now with the digital transmitter versus the old analog one? I am curious how much power is saved after national switchover to DTV. Thanks, I found your channel very interesting.

[@Truckguy1970]

Did the earlier transmitters back in the 40s and 50s also use the 277/480 volt Y service? I've heard some of these earlier systems also used 120/240 volt 3 phase delta systems with a 208 volt high leg usually on the B phase

[@nakayle]

Was this a analog or digital transmitter? Beyond changing the exciter, how much modification is needed to convert a NTSC transmitter to ATSC? How would the resulting output power compare?

[@TheOnLineEngineer]

This is a digital Transmitter and there is not much different between it and an analog one. Just the exciter and output filter. I made a much better two part video on transmitters that you can see on KZbin called - Profile of a DTV Transmitter. You can also see all my videos and Blog at my website TheOLE.org

[@socialite1283]

All the audio sounds good. Footage is all very interesting. That's an awful lot of filtering being done on that transmitter output. Kinda suggests that it's a rather dirty transmitter that needs a lot of clean-up before it is suitable for being radiated.

[@hubzcaps]

yhea boiii

[@vista666]

My old station had one of those.

[@markarca6360]

Grass Valley is now part of Belden.

[@whorton4]

Good video, thanks for it. But the music sounds like an advert for a Pirello tour.

[@denelson83]

Yep, Sutro Tower.

[@jeffsmythe2653]

What is name of the song.

[@diwakarsinghbabu]

Please make a video on R&S UHF transmitter 5kw.

[@diwakarsinghbabu]

Tv transmitter

[@jameskelly1680]

Sadly the IOTs and MSDC IOTs are being phased out and replaced with solid state transmitters. This equipment is obsolete even though it could be repaired and rebuilt indefinitely. They were made to be worked on, and the new ones are not. Comark, Thomcast / Thomson, and Thales IOT and IOX transmitters in that time period were the absolute best. They were beasts. The new Doherty solid state transmitters may be more power efficient, but they are not nearly as good. Even comparing logic control systems, compared to the old tried-and-true Allen Bradley PLCs, the Hitachi Comark (Grass Valley) Parallax now uses a Windows 10 mini PC! Yuk. Terrible. You couldn't kill an Allen Bradley with a sledgehammer. And don't get me started on the cooling systems.

[@Jonathan_O]

Great info but that music! Ugh!!