Towertalk
[Top] [All Lists]

[TowerTalk] RFI From SteppIR SDA100 Controller and PSU

To: towertalk@contesting.com
Subject: [TowerTalk] RFI From SteppIR SDA100 Controller and PSU
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Mon, 25 Nov 2013 23:05:07 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Note this from Ron. What this means is that you cannot use a DB-series SteppIR as an RX antenna for this test, because killing power to the controller essentially disconnects the SteppIR from the feedline. So you must listen for noise with some OTHER antenna when you're making this test with a DB-series SteppIR.

A portable radio that can listen to the HF bands makes an excellent probe for RF noise. I use a Kenwood TH-F6A and a Tecsun PL-380 for this purpose. Fire up the stuff, move the radio around wiring connected to the suspect equipment. When you hear noise, suspect that equipment. Noise is radiated by wires carrying that RF noise current, and received by our antennas.

73, Jim K9YC


-------- Original Message --------
Subject:        RE: [NCCC] RFI From SDA 100 Controller and PSU
Date:   Mon, 25 Nov 2013 15:32:39 -0800
From:   Ron Castro <ronc@sonic.net>
Reply-To:       <ronc@sonic.net>
Organization:   Results Radio, LLC
To:     <k9yc@arrl.net>, <SteppIR@yahoogroups.com>



Jim:

I would add that if you are using any of the SteppIR DB series antennas,
cutting the power will cause the relays in the coax switch to disconnect the
main coax from all of the elements.  Also, the relays in all of the possible
driven elements will 'normal' to passive, shorting the center insulators.
That makes testing for RFI from the controller almost impossible, although
if you can isolate the conductor that activates the appropriate relays (I
think both the switch and passive/active relays in each element use the same
control wire) and apply voltage to it from a linear supply, you can test it
that way.

       Ron Castro
           N6IE
    www.N6IE.com

Member:
                      ARRL
     Redwood Empire DX Assn.
 Northern California Contest Club
Northern California DX Foundation

-----Original Message-----
From: NCCC [mailto:nccc-bounces@contesting.com] On Behalf Of Jim Brown
Sent: November 25, 2013 3:04 PM
To: SteppIR@yahoogroups.com
Subject: [NCCC] RFI From SDA 100 Controller and PSU

Two more of my local friends (W6GJB and W6OAT) have narrowed down severe RF
noise to their SDA100 controller. The PSU, a VERY noisy switching PSU, is
the major offender, but the controller itself also puts out some noise.

If you are experiencing RF noise, turn off your SDA100, unplug the PSU from
the AC line, and listen carefully on all bands. You'll need to tune the
SteppIR to each band, one at a time, before powering down the controller.
If you SteppIR is a beam and far from the shack, point it directly to the
shack before doing your tests.

SteppIR send me a relatively quieter replacement for my 33V supply, but I
still heard it on antennas that are close to my shack (especially on 160M),
so I've gone back to a vintage home brew linear regulated power supply that
I bought from the estate of a neighbor ham.  That PSU, of course, is dead
quiet, but I still hear noise on 160M on the vertical that's right outside
the shack. Hence, when I'm on 160M, I have to kill power to the SDA100.

73, Jim K9YC

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>