Batboard

VHF 9000 Programs and verifies fine. Also reads the Code plug fine. All receive frequencies work fine but on some random Xmit frequencies cause the radio to instantly do a self check. Power in fine and on those frequencies where it works the transmitter puts out about 100 watts. All frequencies are within the standard band split and seam to not have a pattern as to what works or not. Such as 151.XXX works but 154.XXX doesn't, 157.XXX works. Re programmed the radio and the results are the same. Anyone have an idea on this???

Thanks
Russ

What are you using for a power supply? If you're sure it supplies enough current, check the connections. It could be that the voltage is dropping enough on transmit to cause it to reset.

Jeff

I agree with Jeff's comments.

Check your power and antenna grounds. You are using a very wide frequency range. What are you using as an antenna (i.e. does it have an acceptable SWR over this entire frequency range)? Have you checked the antenna tuning at all? Does the problem happen when using a good quality VHF dummy load instead of an antenna?

Check the large red and black power cables in the main radio drawer connector. Sometimes they come unsoldered and can cause all kinds of intermittent problems.

There is a known self check problem with the control heads:
http://www.open.org/~blenderm/syntorx9k ... ml#ch_trbl

Sometimes when C6 first starts leaking the self check problem can be triggered by weird conditions that make no sense.

Thanks guys...Power supply is Astron 30 amp, antenna is VHF/UHF dummy load. The problem occurs on the same frequences and only on the same frequences each time. I can reprogram the radio, go back the next day and it doesn't matter it is always the same. Checked for voltage drop from PS and at pc board and there is almost none. So i can't think it is the bad Caps. Becides, there is no sign of leakage and none of the other bad cap problems are happening. I am really stumped.

The only Astron 30 is the SS-30 switching supply which is only 25 amps continuous. Some of the linear supplies are the RS-20 (16 amps continuous), RS-35 (25 amps continuous) and RS-50 (37 amps continuous). The RS-50 (there are other optional models than the RS) is the lowest rated Astron that can handle the high power Syntor X 9000 Tx. If you are using the switching power supply then maybe it is interacting with the radio in a strange way on some frequencies? This may be the type of underrated amperage power line reset event that requires an oscilloscope to see.

Can you try it in an automotive installation where the Astron power supply is not a factor?

I don't see how you eliminated the control head C6 as a problem by checking the power drop with a meter. You have to physically inspect with a magnifier and probe, sometimes you can detect a bad fish smell, to find a just starting to leak cap. C6 is not a power cap, its a watchdog reset RC timer constant cap. When the cap leaks the value goes down and the watchdog reset cycle gets shorter. The leaking cap value is not always stable either. This puts an early C6 leaker on the edge of causing a watchdog reset when its not supposed to be anywhere near a watchdog reset yet. If anything pushes it over the edge you get a system wide reset (a programming PC is the only Systems 9000 microprocessor connection that does not get reset) and the self check.

Thanks Mike...Hooked up to a battery...same thing. The reason I think it is not C6 (and I have looked closely) is that it is 100% repeatable as to transmitting on a certain freq or not. Seams to me that if it were C6, that sometimes it would work and some times it wouldn't work on random frequencies, that is not the case. It always will or won't transmit on a given frequency.

If you have any Siren/PA or options connected remove them first thing. I assume all your programming passed the verify cycle (if not then you are chasing ghosts).

Try lowering the Tx output power to 50 watts and see if the problem persists.

If it still resets try installing jumper JU500 in the radio drawer personality board and power the radio up. When JU500 is detected on power up the radio goes into test mode. The most important thing is it disables the radio drawer watchdog reset timer. You cannot use test mode for normal operation, but you can see if the resets persist on the selected frequencies. If the resets stop then you have a watchdog timer problem on the radio drawer personality board.

I have never encountered or heard of any Syntor X 9000 problem with reset from a Tx on any particular frequency. You could have some strange ground loop in the radio internal circuits (cold solder joint, extra resistance from loose or partially burned wire, whatever).

If you cannot track down the problem then try parts substitutions. Start with another control head, different radio cable and radio drawer. The problem should go away when one of these is swapped out. Since you already eliminated the power supply, if swapping parts does not isolate where the problem is call an exorcist! If the problem is in the radio drawer try swapping out the personality board. The idea is to localize the problem so you know where to focus your repair efforts.

Thanks again Mike. I will try all this this weekend. As for the exorcist, I have a 10lb one on the end of a handle. I will let you guys know what I find if anything.

Russ

It's Fixed...The problem was the PWR SET Pot. apparently It was set at full power or it was intermitant or dirty. I turned it and found the power jump around. Some cleaner, turning back and forth and setting to 90 watts fixed the problem. Thanks again Mike.

Russ