Got my AM MAX 2 today

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MOSFET
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Got my AM MAX 2 today

Post by MOSFET »

Got my AM MAX 2 today in the 19 inch box. Unfortunately I did not know about you and bought it from one of the re-sellers under another name.

I had no idea that under the hood, it was PCS Elektroniks board. In fact, when looking for AM transmitters on the Internet, your site did not even come up :-( I looked around for about 2 hours. Oh well. Next set I will buy directly from you.

When I applied audio to this box it sounded horrible from factory. Modulation was like 30% and sound really shitty and I connected my oscilloscope. Yes, it was only 30% so I took the lid off and set the compressor to 1:1 and no threshold. Attatched a 1 khz tone generator.

After 1 hours labbing and testing I could trim so I got 100% modulation and peaking 21watts. (I run a 24 Volt power) Then I attached the compressor and set it to 4:1. Threshold about -21. and made the last trimmings to the audio input. Plugged in the 4k filter and attached audio.
I set fast attack and like 400ms decay.

Man!!!!! This TX really sounds GREAT!!!!! The audio is so bright, crystal clear, no distorsion and very punchy sound especially in the bass.

However I have some notes.

The P2Mod is fully turned left = max. I'd like to have just a bit more. (There is headroom when compressor is attached). I am thinking of modifying that with a new resistor.

Also good choice on the IRF510. I use that too in my applications, however it is a little sensitive to high voltages so it will break easily on open circuit etc.

I am now building a linear power amp for this TX consisting of Fairchild FQA11N90 which handles 900 volts. I have never broken anyone. They are really great. I put 6 in parallell and get about 300 watts out. Operating on 120 volts.

PCS, well done indeed. This is a true masterpiece. Nice, tight, clean PCB and reliable it seems.

Another thing I could use is tyhe full AM band coverage starting at 522 kHz. Would that be possible? Could you customize one for me that starts lower than 540?

Ok. Thank you for listening.

Regards
Mosfet
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pcs
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Post by pcs »

Sure, it is possible easily.
Best regards,
Marko - PCS Electronics
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http://www.pcs-electronics.com
fax +386 4 2316 128
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