[RFI] DigiKeyer II

john at kk9a.com john at kk9a.com
Thu Dec 19 10:18:09 EST 2013

Actually I have used a DigiKeyer on SSB from P40A, but only to interface
the radio's frequency data to my laptop. The device works fine as a COM to
USB converter for band data. The mic was connected directly to the
transceiver and not though this device.

John KK9A

To:	rfi at contesting.com
Subject:	 Re: [RFI] DigiKeyer II
From:	 "Dale J." <dj2001x at comcast.net>
Date:	 Thu, 19 Dec 2013 08:45:31 -0600

As I read it, he's using it as designed, CW and RTTY, but when he went on SSB
for the SS contest he had bad set of RFI.  Apparently he's narrowed the
down to the DigiKeyer or it's cabling. Is that a fair summary Peter or do I
have it wrong?

Dale, k9vuj

On 19, Dec 2013, at 8:24, john at kk9a.com wrote:

> I own two DigiKeyer II's and a DigiKeyer and they work well on CW and
> RTTY. This product is designed for digital modes, I have no idea how you
> are using on SSB. You should have purchased a MicroKeyer II.
> John KK9A
> To:    "rfi at contesting.com" <rfi at contesting.com>
> Subject:       [RFI] DigiKeyer II
> From:  Peter Laws <plaws at plaws.net>
> Date:  Sun, 15 Dec 2013 16:15:43 -0600
> IC746Pro, microHAM Digi Keyer II.
> One USB cable from the radio to the interface.  One squid from the
> interface to the radio with 1/4" plug for CW, a 1/8" plug for CI-V and
> a howevermanypin DIN for ACC1.  There are snap-on chokes on the ACC1
> cable and the USB cable from the factory.  The interface is connected
> to the ground bus and the bus is connected to a ground rod buried
> outside the window.  Radio is also connected.  To make sure
> (hopefully) there was nothing coming down the coax, there is one of
> those Palomar buildityourself chokes on a foot long piece of LMR400 in
> the shack.
> Interface works OK and I played a little in CQ WW RTTY and November
> Sweeps CW.  I use FSK not AFSK so that's hard keyed as is the CW (I
> think I set it to use the internal K1EL chip).  All of that works
> great.
> But when I went to play in SS SSB, I had horrible horrible RF getting
> into my audio.
> I finally had time today to troubleshoot.  SWR (on three wire antennas
> coming through an Ameritron remote switch) was acceptable but best on
> the WARC band trap dipole (in fact, I'd forgotten just how well that
> antenna works even without the tuner.  I went to 17 where I knew the
> SWR was good and did some tests. I can hear the distortion through the
> headphones with the monitor on.  Unplugged CI-V, no change.  CW, no
> change.  Unplugged ACC1 .... no more distortion.  Got on 17 and
> chatted with a feller up in Indiana and he heard no distortion either
> (though I gather the HC4 in my Heil boomset wasn't doing me any
> fidelity favors :)).  Plug ACC1 back in, back to interference.
> Interestingly, this unit doesn't power itself off the 5 V available on
> the USB connection but off the 8 V available off the ACC1.
> I've added two more snap-ons of unknown mix to the big cable from the
> interface and this has made no difference.
> Ideas?  More ferrite, I assume?
> I used a RigBlaster Plus for nearly a decade that pulled audio and
> keyed FSK and CW via ACC1 and never had this issue.  I don't even
> think it had ferrite on the cable.
> --
> Peter Laws | N5UWY | plaws plaws net | Travel by Train!

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