![]() (Most manufacturers will tell you a wye is OK but when pressed to the wall admit that a delta is superior. What led me to this conclusion started with years of frustration banging my head against the wall trying to find out why my FM across the street from another FM using the exact same equipment from the microphone to the antenna ( they were on a delta and I was on a wye. I and many others have had severe problems running FM transmitters on a wye connection. You could not be more wrong, I suggest you look at the Harris white paper on AC power in located the rear appendix of every Harris transmitter manual. Granted it won't fix frequency variations, but may help with the transmitter being slammed when going to, or coming off of generator. Harris micromax exciter plus#When I make a trip back to the West Coast next month, I'm going to run the exciter-only AC through a SOLA ferroresonant transformer I've got laying around, plus will be installing a newly purchased Transtector SAD surge suppressor right on the transmitter AC input. Apparently this transmitter is really touchy when it comes to AC. ![]() ![]() We had to send someone up to power cycle the transmitter at the breaker to return to air, due to lost drive. Even when utility AC returned and the site returned to normal acouple hours later, the exciter triggered all the alarms and shut down again. Harris micromax exciter generator#This past Tuesday we blew two PA modules and had the exciter lock up with AFC critical alarms when the generator came on line due to power failure. About a year ago our site landlord installed a propane fired Onan generator which they test with-load every week. It looks like flakey power from a backup generator may be the culprit. As a beginning bonus there is almost always at least a 10 DB or more improvement in incidential AM I will admit I have come across a few wye sites that performed well but they are few and far between and are usually in somewhat rural areas with a closeby substation with residential loads well balanced across the three phases. Since 1975 I have changed 25 or more major market stations from wye to delta with outstanding results every time. You may have to fight with the utility for closed delta, best approach is 3 wire 240 volt service using a small delta/wye bridging transformer to derrive single phase loads If that is not possible use a 240 delta/208wye dry transformer backfed in reverse just to feed the transmitter works extremely well. Harmonics at any other bizarro combination go right into the transmitter causing problems and symptoms that may suprise you. ansmitter power supplies are filtered only at 360 hertz. A Wye connection has no provision to contain harmonics where as they circulate within the delta and do not enter the transmitter. Printers, switching power supplies and the worst offender of all power saving light fixtures in office buildings and industry. ![]() AC power is so polluted with harmonic content due to UPS's, Laser ![]() In 2012 it is far more important than ever. Manyĭid not necessarily know the the electrical theory behind why but knew that it was the proper way to do an AC installation. Something important has been lost over the years in broadcast engineering, if you talk to old line engineers you will find that 90% of pre 1970's broadcast stations had closed delta installations. Both transmitters ran for years without incident. After a through cleaning before reinstalling I had no further problems with this transmitter, in fact it was so flawless I bought a second Z-5 CD for use as main and alternate. Moved this transmitter to a new immaculate site with a closed delta AC feed andĪ transmitter room temp of 70 degrees year round. Had two Z-5CD transmitters, first one was installed at a very dirty site with crappy AC power and no A/C always seemed to have a module in trouble. ![]()
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