Good to know information! However, I have done extensive testing with two different hand held radios. The buzz will occur when both radios are operated with their own batteries and no external connections. For what it's worth, the buzz is not 60Hz. My guess would be around 200Hz.
Thanks. --- In [email protected], "Laryn Lohman" <[EMAIL PROTECTED]> wrote: > > My Yaesu handheld will often buzz when receiving the local repeater > when the charger is plugged into the side of the radio. I know what > you are thinking-- those cheap wall chargers are not filtered very > well, that's why I'm hearing buzz. That may be true, but the buzz I > am hearing is not from skimpy filtering of the DC feeding the radio. > I believe it is caused by the rectifier diodes in the charger, which > will cause a form of intermod to be produced, which basically > modulates RF at a 60 or 120 cycle rate. The level of buzz will vary > greatly as I move around the radio, touch the radio, etc. Certain > positions will produce intolerable buzz, others none at all. > > I know, the charger does not directly handle any RF. But it is > inevitably a part of your antenna system whether receive or transmit, > especially when using a duck on a radio. Therefore, RF on the wire to > the charger, and the AC side too, ends up in the rectifier diodes, and > is <modulated>. I've notices this phenomenon on other radios too, not > just my Yaesu, just as you have. > > I think you are experiencing the same thing that I do here. I haven't > <benched> the theory presented here to prove it right or wrong, but it > might be useful to try some small RF bypass caps on each diode in your > power supply(s)... Or, ferrite chokes on the wire from the charger. > > Laryn K8TVZ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
