EMRFD Message Archive 4014

Message Date From Subject
4014 2010-01-18 19:17:37 WA0ITP 60 Cycle Hum on End Fed Wire
I have the opposite problem with a D C receiver using an NE602 mixer. I'm using
a battery, and it's quiet until attached to the antenna (a random end fed wire)
then monstrous 60 cycle hum. The antenna must be coupling to the neighborhood's
power lines, even tho it's routed over a vacant lot and not close to power
lines, except at the house.

First I tried a hi pass filter, then isolated one of the bnc jacks on the filter
enclosure, but I've not been able to block or shunt it yet. Next is a binocular
isolation transformer.

Any thoughts to help eliminate it would be greatly appreciated.
-------------------------------------------------------------------
Back to the bench, Winter's too valuable to waste!
I love this radio stuff !
72, 73 Terry, WAØITP
www.wa0itp.com
www.4sqrp.com
www.qrpspots.com



----- Original Message -----
4025 2010-01-19 05:13:15 Vojtech Re: 60 Cycle Hum on End Fed Wire
Hi Terry.

I suppose the NE602 has poor VFO to input isolation and there is a place near your antenna, where the radiated VFO mixes with the 60Hz power line current on some nonlinearity, which may be a diode in power supply or bad joint, which acts as a diode.

If you don't find the place where the hum gets modulated, I suppose the only way to minimize the hum would be to decrease VFO radiation by isolati
4026 2010-01-19 05:37:32 WA0ITP Re: 60 Cycle Hum on End Fed Wire
Hi Vojtec,

Thanks for the info, appreciate it.

-------------------------------------------------------------------
Back to the bench, Winter's too valuable to waste!
I love this radio stuff !
72, 73 Terry, WAØITP
www.wa0itp.com
www.4sqrp.com
www.qrpspots.com



----- Original Message -----
4064 2010-01-22 10:36:55 davidpnewkirk Re: 60 Cycle Hum on End Fed Wire