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RadioMan
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I am experiencing a slight hum on my signal. I am using a regulated power supply at 13.5vdc. I tried using a 12vdc battery to trouble shoot and it is still there. I don't have a SWR metering device. Could this be the problem? (I didn't think so but a friend said it may be).
Any ideas
RM
Sun Jan 18, 2004 9:25 pm View user's profile Send private message
Sir Nigel
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No SWR doesn't seem to be it. I think it's something with the audio (not saying you have a poor audio feed). Perhaps a bad stereo encoder?

What broadcaster are you using?

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Mon Jan 19, 2004 4:49 am View user's profile Send private message Visit poster's website
RadioMan
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I'm just using MAXII. No encoder for now. My audio in is from a Mackie 1202 mixer...pretty quiet. Have 2 mics, 2 CD player , 1 tape cassette-no hum after mixer. I also experimented with this OVERsized wall wart for power(I opened it up...slightly...and saw an IC "7815" diodes and caps so I assume it's not a wall wart but a regulated PS looking like a wart)...the hum was the same with it. I've tried grounding all componets including the devices that are input into the audio mixer.
Any help appreciated.
radioman
Tue Jan 20, 2004 9:45 pm View user's profile Send private message
pcs
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MAX PRO II?

RF signal might be getting into your mixer and power supply
and causing hum. How close is antenna to your audio gear?

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Wed Jan 21, 2004 5:06 pm View user's profile Send private message Visit poster's website
RadioMan
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At the moment, antenna is close to x-mitter (MAX PRO II)...same room about 10 feet. I will try moving antenna to another room. Landlord will not allow me to run cvable & put stick on bldg. If I dissconnect all gear from unit the signal is clean. No noise at all. It could be induction so I will seperate things. A curious thing happened yesterday while playing with stuff. For the heck of it I connected the whip antenna from my police scanner(50ohm but only 6 inches long) to the unit, all placed inside my apartment about 15 feet above ground level, power set to full. I went out for a drive to check signal. In a W/NW direction it went about 1 mile. S/SE however was good for about 7 miles. I got scared and ran home to turn it off. I never thought I would get a directional signal wisth that little antenna?

Thanks for all your help
Wed Jan 21, 2004 7:09 pm View user's profile Send private message
Sir Nigel
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Thanks for the tip about seperating the antenna from the transmitter pcs. I'll have to try that.

RadioMan, what type of antenna are you using?

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Wed Jan 21, 2004 11:28 pm View user's profile Send private message Visit poster's website
RadioMan
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Antenna is a homemade J-Pole (is there any other kind?)

I fixed my hum. It was either RF induction on audio gear or some sort of ground loop. The fix was to put a transformer in-line with mixer-out to x-mitter-in. I got it at RadioShaq ($15.00) a few years ago when I was doing Video Production (to match my VCR's audio-in to BIG pro sound mixers at concerts. I would take a feed off the sound board and run it into my gear. Talk about Ground Loops!

New Question- I have tons and tons of RG-59 coax and not very much money. Is there a way to match the impedance of my 75ohm RG-59 and my 50ohm gear so I can run it a good distance (only 100-200 feet)????
rm
Fri Jan 23, 2004 10:19 pm View user's profile Send private message
RadioMan
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When tuning my MAX Pro II, what is a good voltage to be read at the PWR point? I am getting 5Volt. Just curious.
Fri Jan 23, 2004 10:35 pm View user's profile Send private message
pcs
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The more the better.

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Best regards,
Marko - PCS Electronics
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Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Tue Jul 20, 2004 9:58 am View user's profile Send private message Visit poster's website
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