MSF 5000 Beeps twice after power up-WHY?

Ray D O · Post by **Ray D O** » Fri Mar 26, 2004 7:16 am

Looking for this for a fellow tech. MSF has had freq. change-VCO's locked. Still no work-beeps twice. Any input would be appreciated. Thanks

Post by **xmo** » Fri Mar 26, 2004 7:30 am

http://batboard.batlabs.com/viewtopic.php?t=13805

wm4t · Post by **wm4t** » Mon Mar 29, 2004 7:29 am

If you have changed frequencies you may have moved the PA output impedance just out of the range of what the PA is looking at. Two beeps is PA failure but literally it can be no more than high swr, over power level ie: PA or exciter. Run it into a dummy load. Also check the drive level too, there are several things that will give you this alert. Basic indication is PA failure which is a broad explanation.

Sam

MSS-Dave · Post by **MSS-Dave** » Mon Mar 29, 2004 11:22 am

Does the PA full and key LED come on and go right out when keyed? If so, try reducing the power output control to half or so. If this works, the drive is too high or the cutback is set too aggressive. If it still doesn't work, try this. Put a dummy on the TX line, open the tray, flip up the panel and look for JU1 on the SCB. It will be toward the bottom rear of the board. Move the jumper to the alternate position, the red test LED on the front will now be on. Pull the connector on the power control cable (left side of the station between the RF tray and the amp, gray cable, Molex plug). If your station has the single or dual external circulator with the load under the PA, pull the brown wire from this also. Test the output now by keying from the switch on the front of the SCB. If you get full power, something is up with either the amp or the external circulator but you need to make sure the spectrum is clean when TX at full power. If the amp goes trashy, the internal single circulator reflects out of band energy back at the power detector in the amp. I've had lots of failures like this. There will be a bad module in the PA that can be repaired sometimes with resolder or replaced. If you do have external circulator, these can fail also, if the amp passes the spurious test, try bypassing the circulator and look at the output directly. Whatever you do, DON'T run the station with the JU1 in and the power control cable unplugged other than to test. There is no control to power and it will eventually burn up, especially if there is damage to a module.

Dave