digital fm amplifier 40W doesn't work

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anhtuanb
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digital fm amplifier 40W doesn't work

Post by anhtuanb »

Hi guys, I recently bought a 40W digital FM amplifier with SWR meter. I checked all my connections and they're all solid and good continuity, but the power comes from the amplifier doesn't register on my SWR meter (SX-600). The onboard SWR doesn't show any light at all. It powers up fine, with the light show on both green and red bar but I got nothing on my sx-600, nor the onboard's swr.

I have a 12.5V input with a meter to show the amperage draw. The amp meter indicates .1A at 12.5V when the amplifier is on at 50% level. The fan runs correctly, automatically adjust the fan speed up and down as the level changes.

Everything seems to be working but nothing register on my SWR meter. I had the SWR meter on Power forward meter so it can measure the power output, and it's showing 0. I then removed the amplifier and connect my .5W transmitter directly to my SWR meter and it shows .5W of power, which is in the input range of the amplifier.

Can you help me diagnose this issue?

Thanks.
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pcs
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Post by pcs »

Open the top and look for jumpers, install both jumpers for maximum
sensitivity.

While 0.5W is enough for 25W booster 40W unit sometimes needs up
to 1W to produce full power.

Still, you should get at least 20W with 0.5W.

Also, if you can get your power supply higher towards 15V there
will be more power output.

Hope this helps.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
anhtuanb
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Post by anhtuanb »

Thank you pcs.

It's working now. I put it on maximum sensitivity by shorting the 2 jumpers you suggested.

Should I always have the input voltage closer to 15V the better for maximum efficient fm output?
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pcs
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Post by pcs »

You don't have to, but it gives slightly more output power.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
anhtuanb
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Post by anhtuanb »

Thank you for your support.
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