|JUMA PA1000 LDMOS replacement instruction
If your JUMA PA1000 stops providing normal power with 10W drive power the LDMOS fet may have failed. The LDMOS failure is typically caused by a sudden short or open circuit in your antenna system including everything from PA1000 to antenna. It may generate extremely fast high energy flyback to the final stage.
You can confirm a LDMOS failure by checking the bias (idle) current indication in the LCD when PA1000 is activated in TX state (TX led should be on) with zero power drive. The nominal bias current is 2.0A +-0.4A.
Please don't just replace the LDMOS. You should find and repair a weak point in your antenna system. Do not use an antenna tuner which is the main cause for the failures. This is especially important when the antenna native SWR is high or unknown.
JUMA PA1000 can stand any SWR and will smoothly go to protection but a sudden short or open circuit in your antenna system during high power transmission may cause a failure.
This LDMOS replacement instruction is particularly intended for PA1000 amplifiers after the one year MOSFET warranty. If you repair your JUMA PA1000 during the one year warranty period the warranty is void.
Download the PDF instruction here PA1000-MOSFET-replacement-instruction-2021-04-03.pdf
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