Quantar Issue: Random Tx Cutout

[W1HVN]

Recently a new issue has arisen with a 25 watt VHF with v16 firmware silver Onan unit. This was a Dave in Colorado unit and is used in Amateur Service.

In repeater mode configured for mixed mode and 15 watts output she randomly drops the transmitter. Receiver is working fine however the tx just drops. No re-creatable circumstances which can be identified as a precipitant.

RSS shows no alarms or recordable PA/TX events when it occurs. The TX just drops.
All settings same as previous two years its been running without issue.

Understanding it may be an exciter or PA failure, anyone heard of this or know of any firmware history associated with this problem?

Thanks

[d119]

Internal SCM-based controller, or external controller?

[W1HVN]

All in cabinet internal.

[d119]

Weird. Have you tried another SCM?

[radioactive69]

Maybe the 25w PA set at 15w is under-driving the Final stage. Is the 15w out of the duplexer or out of the PA direct?

[chartofmaryland]

Check the power supply voltage,

I had a quantar feeder for a Quantro which went "green" on Tx but was loosing voltage that didn't show as the point of drop was after the monitoring point for the station status. The Exciter would lock, PA Full came up and look happy but made no output.

Power supply failures are not often but do make themselves into a mess when it happens.

Something to check

CoM