Slight hum (possible RF?) on the bnc connector
Posted: Mon Sep 13, 2004 2:48 am
I've received Cyber MAX FM about a month ago and have been very pleased with it. The level of support I've received (due to my lack of understanding of some things) has been outstanding. Kudos to Marko and his crew for engineering a great product.
After a few minor items I got ironed out, there is one remaining thing I still seem to be experiencing.. a slight hum when the cybermax is on, and I don't believe it to be due to the power supply (a Pyramid PS-12 KX)
nor the audio line feeding the unit.
What I've experienced is a hum which I've managed to make go away by slightly jiggeling the antenna connecting to the back of the unit. My antenna is at least about 50-feet away from the unit, and on another side of my studio (which is actually located underground) and the Belden 9913 cable I'm using, I've tested for any shorts, that doesn't seem to be an issue.
I believe that because of the fact the hum will go away if Imanipulate the antenna cable, some RF feedback may be bleeding through (or back) to the unit somehow, but here is the weird thing; If I connect my SWR meter in line and run a cable out from the back of the cybermax first to the SWR and then connect the antenna to the output of the SWR, the hum is non-existant!
What I'm guessing is somehow by connecting the SWR meter, the power is being reduced somewhat, and not as much hot RF is coming right back out of the unit, and thus not causing a problem. Not being an engineer/techie type person, this is only conjecture on my part, but perhaps some of you who have used this device before or have a wider range of knowledge can impart some wisdom or insight on me?
Thanks in advance for any advice or thoughts.
Cheers!
`JT~
((RadioBoy))
After a few minor items I got ironed out, there is one remaining thing I still seem to be experiencing.. a slight hum when the cybermax is on, and I don't believe it to be due to the power supply (a Pyramid PS-12 KX)
nor the audio line feeding the unit.
What I've experienced is a hum which I've managed to make go away by slightly jiggeling the antenna connecting to the back of the unit. My antenna is at least about 50-feet away from the unit, and on another side of my studio (which is actually located underground) and the Belden 9913 cable I'm using, I've tested for any shorts, that doesn't seem to be an issue.
I believe that because of the fact the hum will go away if Imanipulate the antenna cable, some RF feedback may be bleeding through (or back) to the unit somehow, but here is the weird thing; If I connect my SWR meter in line and run a cable out from the back of the cybermax first to the SWR and then connect the antenna to the output of the SWR, the hum is non-existant!
What I'm guessing is somehow by connecting the SWR meter, the power is being reduced somewhat, and not as much hot RF is coming right back out of the unit, and thus not causing a problem. Not being an engineer/techie type person, this is only conjecture on my part, but perhaps some of you who have used this device before or have a wider range of knowledge can impart some wisdom or insight on me?
Thanks in advance for any advice or thoughts.
Cheers!
`JT~
((RadioBoy))