MAX PRO IV+ with 600W Pallet

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Carlos
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MAX PRO IV+ with 600W Pallet

Post by Carlos »

Hello, I drive the 300W fm amplifier with just 1w from the Max Pro 4+, but I have just bought the 600w pallet and I need a minimum of 6w of rf input and I can not reeach more than 4.5w from Max Pro 4+. What can I do?
The power supply can reach 15Vdc - 4Amps (14V adjusted), the power from the lcd lcd is at the maximum and the output is connected to a Daiwa CN-801 and a dummy load.

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pcs
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Post by pcs »

Where did you get MAX 4, it must be 6 years at least since we stopped selling those?
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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Carlos
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Post by Carlos »

I got MAX PRO IV+ from PCS in 2005 I think. Also I bought SE4 DSP encoder and RDS MAX 2.0 and upgraded to 3.0.
If you have no support I understand. Thanks.
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pcs
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Post by pcs »

Hi,

I'd look at the two resistors setting the bias. There was one 2K2, if I remember correctly, close to output transistor. R37 at the board edge. If its 2K2 replace with 2K7 or 3K3.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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Carlos
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Post by Carlos »

I have replaced R37 with 3k3 and the output is about 5.5 watts now. I have also found the cd manual and I have compressed and expanded some coils reaching nearly 8 watts. This is enough to drive the pallet but I will have to use a fan because the Max Pro final transistor is running too hot.

Thanks for your help.
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pcs
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Post by pcs »

Sounds good. You could increase that resistor more, but why risk failure?

Consider upgrading to MAXPRO3000+, much better.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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