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Harris FX Transmitter

I wondered why you were either off or very weak here in Lexington a few days ago.....
 
DaveatWCYO said:
We were only producing a few hundred watts out of the transmitter. You should have a good signal now.
Click to expand...


No. I've never heard anything but good about them. In fact, I know of a ZX-3500 that runs at over 4000 watts 24x7 and has done so for a couple of years with no issues.
 
Harris was very helpful with the problem and rushed the parts to us. I found one of the combiner's coax cables loose. The center conductor had become unsoldered from the circuit board. Maybe it had been hot or it was a bad solder joint (No recent lightning). I reconnected the cable and still had problems with power fold-back. We then replaced the combiner and the problem was corrected. Not an easy job to install the new combiner, a very tight fit. Earlier I had attempted to pull the different modules hoping to get the power up until the parts arrived. I even switched the back-plain and reset the dip-switches on the module showing an alarm. I suspect that, with a combiner problem, the equipment was seeing a high reflected power from one or more of the RF modules and this caused the power fold-back. If you have a ZX, you may want to have a look inside the combiner, the next time you do maintenance. Pay close attention to each of the coax cables, especially the center conductor, to ensure the solder joint is OK. As I said earlier, this is the first issue we have had with the ZX-3500. I like the transmitter and the ability to hot-swap the modules, (RF and power supply).
 
DaveatWCYO said:
Harris was very helpful with the problem and rushed the parts to us. I found one of the combiner's coax cables loose. The center conductor had become unsoldered from the circuit board. Maybe it had been hot or it was a bad solder joint (No recent lightning). I reconnected the cable and still had problems with power fold-back. We then replaced the combiner and the problem was corrected. Not an easy job to install the new combiner, a very tight fit. Earlier I had attempted to pull the different modules hoping to get the power up until the parts arrived. I even switched the back-plain and reset the dip-switches on the module showing an alarm. I suspect that, with a combiner problem, the equipment was seeing a high reflected power from one or more of the RF modules and this caused the power fold-back. If you have a ZX, you may want to have a look inside the combiner, the next time you do maintenance. Pay close attention to each of the coax cables, especially the center conductor, to ensure the solder joint is OK. As I said earlier, this is the first issue we have had with the ZX-3500. I like the transmitter and the ability to hot-swap the modules, (RF and power supply).
Click to expand...


I don't have a ZX transmitter in Louisville, though I'd love to have a pair of ZX5000s for WSFR. They make a 10KW transmitter like that, with the ZX5000s combined. I'd get a ZD series except that site doesn't have 3 phase electric, and at 7KW I'd need an extra ZD cabinet for the power supply. Two ZX-5000s would run on single phase and give lots of redundancy.

I have 6 of the ZD series transmitters at my other sites. The ZD uses the same power modules as the ZX series. Each of my transmitters has 16 modules, so that's 96 total. I've had one failure, which was due to a lightning strike. (The transmitter just kept on working at full power, but the fault light came on and the fan sped up until I replaced the bad side of the module.)

They're great transmitters.

By the way, the ZX3500 I spoke of earlier runs at 4100 watts. It's at WPUP in Athens, GA. I'll pass your advice along to their chief.
 
Harris ZX 3500 issue

Any of you folks caring for a Harris zx-3500 have an intermittent issue as follows? At a random time, maybe once every other week, the power backs down from 92% to about 4%. Voltage stays the same, but the current drops way down. The way to fix it is turn the transmitter off and right back on and everything is normal. I've talked to Harris, they've not experienced this specifically, but if I could find a pattern they may have some more input. Anybody seen this scenario...and have you figured it out???

Henry Royse
WCLU-FM
Glasgow, KY
 
gilbaradio said:
Any of you folks caring for a Harris zx-3500 have an intermittent issue as follows? At a random time, maybe once every other week, the power backs down from 92% to about 4%. Voltage stays the same, but the current drops way down. The way to fix it is turn the transmitter off and right back on and everything is normal. I've talked to Harris, they've not experienced this specifically, but if I could find a pattern they may have some more input. Anybody seen this scenario...and have you figured it out???

Henry Royse
WCLU-FM
Glasgow, KY
Click to expand...

What's your drive doing when the power drops? Do you get a full set of readings, including exciter, IPA, and PA amps before restarting the box? Are there certain modules that shut down when this happens, or does your drive go way down?
 
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