Thanks, Bob, for your concise description of how you use your NCC-1 with your
K3---it is very helpful to me as I am almost confused by all the choices of
configuration---a lot more ways to set it up than I thought.
My situation is that I plan (at least initially) to use only 1 un-amplified
noise antenna into the B input of the NCC-1 along with a DXE Receiver Guard
(high RF limiter to protect both rig and NCC-1 during xmit) since my transmit
antenna is a mere 20 feet or so from my operating desk.
I'll see how that works and then add a second noise/receive antenna to the A
input. Both noise antennas will be simple vertical wires or short indoor
dipoles here in our small rented condo; maybe one will be longer and bent
around corners and windows out to the back balcony. I can't really put the
noise antennas outside the shack as our windows and back balcony are screened
in with fiberglass in a frame that the owner installed that I would be very
reluctant to mess with. At least my xmit antenna is outdoors and a bit higher
up. While I am on a multiband inverted U dipole now I am almost finished
building a really fine magnetic loop as mentioned in my earlier post; it will
probably be an improvement over the inv. U to start with and its high Q will
undoubtedly help with the RFI hash before I put the NCC-1 to work, too (fingers
crossed). Ultimately I will also employ a second and third STL (mag loop) as
noise/receive antennas for diversity reception and better noise nulli
ng once I am able to put them in place. But that may a lot more tricky than I
imagine if I will have to constantly re-tune them as well as the main
transmitting loop---so we'll see how it goes with the simpler vertical wires
first.
I got the big box from DXE yesterday and lo and behold, the NCC-1 is almost the
same size and heft as my loaded K3/100! I still need to make up some RG58
jumpers so I can hook it all up but I will try to do so tomorrow during the
WPX (been delayed with other stuff all week so am not ready to get it up and
running just yet). I want to make sure I hook it up correctly and your reply
has certainly given me a clearer picture of how to accomplish that now.
Since my noise antenna(s) will not be active I will set the internal dip switch
to external power for the noise antennas and keep power from being applied to
that port completely.
Also, since I run QRO most of the time (and my STL will be set up to handle 650
watts from my KPA) I will make sure that the TX control line is plugged into
the K3's PTT jack and that the BNC receiver Guard is correctly placed ahead of
both the NCC-1 and K3 RX input.
I considered spring for one of DXE's sequencers but as I am already over budget
on this shebang I decided to go with the less expensive Receiver Guard
initially. Hopefully this will suffice with no further gear inline
required---but if anyone here thinks that is still unwise please speak up ASAP*
as I want to try to get this going sometime Saturday during the WPX---I'll need
it with the current noise on most of the bands here.
(*If I AM running the risk of damaging my receiver/NCC I will not use it at all
during QRO operation until I can eventually get a sequencer in line, too)
Fingers crossed and hoping that I will be OK with what I have now so I can
start enjoying this fine piece of gear right away.
Thank you again, Bob for helping me out; it is very much appreciated. I can't
wait to watch the noise diminish on my P3, too.
Vy 73,
Jeff, NH7RO
K3 #5528 P3 #1397 KPA500 #0250
> Date: Fri, 27 Mar 2015 00:11:03 -0600
> From: n...@whitemesa.com
> To: cathrowinternatio...@hotmail.com
> CC: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] Anyone using a DXE NCC-1 with K3?
>
>
> I have local noise problems which come and go depending on time of day,
> day of week etc. I didn't like the idea of having a noise cancelling
> device in the high power transmit path, so picked up a DX Engineering
> NCC-1 which is perfect for use with my K3, inserted between the antenna
> OUT and antenna IN jacks. I have a horizontally polarized loop which I use
> as the RX antenna on the K3 when I need to fight noise. A vertical doublet
> antenna is used as the transmit antenna, which serves as the noise sense
> antenna in receive when the NCC-1 is active.
>
> To do this, the loop antenna goes to antenna port A on the NCC-1
> (receive antenna input), K3 antenna OUT (from the transmit antenna)
> goes to antenna port B on the NCC-1 (noise antenna input) and the
> output of the NCC-1 goes to the K3 antenna IN. K3 KEY OUT goes to NCC-1
> T/R CTRL to put it in bypass when the K3 is keyed.
>
> Now I have 3 choices:
>
> 1. If I then select the RX antenna on the K3, the NCC-1 is inserted and I
> use the quieter loop antenna for receive while nulling noise with the
> NCC-1 controls. 2. If I don't select the RX antenna on the K3, the NCC-1
> is bypassed, and the transmit antenna is used for receive. 3. If I select
> the RX antenna on the K3, but turn the NCC-1 OFF, then I receive on the
> loop antenna, but the signal passes straight through the NCC-1 from
> antenna port A to the output without modification (sometimes that's all
> that's needed, it's much quieter than the vertical when it comes to the
> nearby noise pollution sources).
>
> The NCC-1 can provide a very deep null on the receive loop antenna for
> vertically polarized noise which is "heard" better on the vertical. The
> trick is to correctly balance the levels of the two antenna inputs on the
> NCC-1. The balance and phase controls are very precise and repeatable, and
> the phase control has a wide range. Having the P3 to look at helps in
> identifying the noise and finding what can be a very sharp (but deep)
> null.
>
> There are complications. One is that when the NCC-1 is active I need to
> disable full QSK on the K3 in CW mode so that the internal bypass relay in
> the NCC-1 doesn't make a lot of noise as it follows the keying.
>
> The other involves antenna tuners. I use a KAT500, and if a frequency
> change causes it to recall new L and C settings then the NCC-1 phase
> setting may need to be touched up because the phase of the noise signal
> from the transmit antenna is changed (and the NCC-1 null can be very sharp
> indeed).
>
> But for me the benefits have far outweighed the costs.
>
> Bob NW8L
>
> On Sun, 22 Mar 2015, Jeff Cathrow wrote:
>
> > Am contemplating a purchase of a DXE NCC-1 receiving antenna/noise phasing
> > unit very soon (tomorrow, actually---so I will have it in time for the WPX
> > next weekend) for use with my K3/P3/KPA500 and was wondering if anyone else
> > in the group uses one and how they have it configured. Apparently I will
> > either need to run it via my RX antenna jack or else with a sequencing unit
> > (or RTR-1A controller that DXE also sells) if I want to run it inline with
> > my main antennas.
> >
> > My main usage will be for the reduction of RFI that I am often subject to
> > here in our condo complex (plasma or LCD TVs, wall warts and other
> > electronic RF garbage producers nearby). I currently use an old JPS ANC-4
> > with its attached noise receiving whip that works fairly well---but could
> > still be much better. (I don't plan to buy the active antennas that DXE
> > also sells with or without the NCC-1; at least not for any foreseeable
> > future).
> >
> > I also use my Elecraft PR6 6M preamp affixed via the XVTR or RX antenna BNC
> > jacks and am wondering if I can run the NCC-1 through it with or without
> > the PR6 being on (I have it wired so that the PR6 activates only when I am
> > on 6M, IIRC)---but I am getting older these days and am more easily
> > confused/dyslexic when it comes to IN/OUT jacks than I used to. Will it be
> > fairly easy to run both together or will it require removing the PR6 if I
> > want to run the NCC-1 through the RX ports?
> >
> > Any user comments or thoughts on the subject will be appreciated; I have
> > seen a few YouTube videos on the NCC-1 and it looks like it can be very
> > effective on QRN coming from one particular source (like my ANC-4 but even
> > noticeably better). It certainly will be fun to see the noise disappear or
> > fall dramatically on my P3, too!
> >
> > 73, Jeff, NH7RO
> >
> > K3/P3/KPA500
> >
> >
> >
> >
> >
> >
> >
> >
> > ______________________________________________________________
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> >
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