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Bluebird
Intermediate Member
Username: Bluebird
Post Number: 146
Registered: 2-2004
| | Posted on Friday, January 28, 2011 - 3:37 pm: | 
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does anyone know what the bias set up is for this radio? mosfet erf 2030s..cant find any info ,,only the s9 and they are different. s980 does not have the shorting bar..got to replace a blown final,,(I MEAN BLOWN UP IN 2 PEICES) any help on bias procedure would help,,,thanks...
mitchell
bluebird
cef 398
cvc 113
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Bluebird
Intermediate Member
Username: Bluebird
Post Number: 155
Registered: 2-2004
| | Posted on Wednesday, February 23, 2011 - 5:54 pm: |
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Magnum S9, S980 with 0619R4,0619R6 PCB Bias adjustments
Set the radio to SSB. Mic Gain fully counter clock wise.
Remove the jumper at TP9 and install a DC milliamp meter across the two pins. Press the PTT and adjust VR11 to obtain 20-30 mils of current draw with no modulation. Re install the jumper.
S980 radios only = Remove the jumper at TP8 and install a DC milliamp meter across the two pins. Press the PTT and adjust VR20 to obtain 50-60 mils of current draw with no modulation. Re install the jumper.
Remove the jumper at TP7 and install a DC milliamp meter across the two pins. Press the PTT and adjust VR10 to obtain 80-90 mils of current draw with no modulation. Re install the jumper.
The bias is now set correctly.
It is critical that the 2 final ERF 2030’s have the same letter code(Vgs) and the ceramic insulators are 1.6mm thick. The amplifier will fail if the insulators are thinner than 1.6mm
thanks to mr lewis
mitchell
bluebird
cef 398
cvc 113
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