[Elecraft] RX SHFT=8.0 I.F. Image (16 kHz) Nulling

[David Orman]

I've figured it out. Two part solution:

1) You don't hear any signal once you've tuned 16kHz off, the manual seems
to indicate you should. You won't. I think this might be a carry-over from
the first RX shift 8 section. You hear the tune once you engage the -1.1
RIT.

2) When using the PX3 as the signal source, the signal for 160m and 80m
when trying to run the 16kHz procedure has the proper settings lost in
noise. That's why APF was failing on them. I manually tuned ignoring APF
and was able to null properly. This explains the notes re: specific
frequencies to try, which probably would have avoided the issue I ran into
on these two bands.

Thank you everyone,
David

On Mon, Feb 16, 2015 at 3:14 PM, Matt VK2RQ <matt.vk2rq at gmail.com> wrote:

> Ok, I reviewed the procedure -- it's been a long time since I did it.
>
> I think there is an error in the procedure. What you should do is tune the
> KX3 to the *same* frequency as your signal source. You should be in CW
> normal mode, RIT off, and you should verify that the signal source is
> giving a strong signal S9 to S9+30dB. If it is not in this range, you
> should set the preamp/attenuator settings to bring it in range.
>
> *Now* you tune the KX3 VFO up 16 kHz, and set the RIT to -1.1. The signal
> you now hear should be the image, which you should try to null out.
>
> Sorry for the confusion before, I should have reviewed the procedure
> before commenting.
>
> 73,
> Matt VK2RQ
>
> On 17 Feb 2015, at 7:14 am, Matt VK2RQ <matt.vk2rq at gmail.com> wrote:
>
> Hook up the RX I/Q output to a pan adapter program on your PC (enable the
> output first, use a stereo input on your PC) and you'll be able to see the
> amount of shift between your signal source and the KX3's LO, and you should
> also be able to see the image. This graphical representation will help you
> to see what is going on at a glance.
>
> 73, Matt VK2RQ
>
> On 17 Feb 2015, at 12:11 am, David Orman <ormandj at corenode.com> wrote:
>
> RX Shift is definitely set to 8.0, on every band. I had to do that for the
> previous step, which went successfully.
>
> Thank you,
> David
>
> On Mon, Feb 16, 2015 at 3:36 AM, Matt VK2RQ <matt.vk2rq at gmail.com> wrote:
>
>> I'd say you have RX SHFT set to "nor" instead of "8.0". If you set your
>> sidetone to 550Hz, and 8kHz shift is not enabled, then you'll pick up the
>> image 2 * 550 Hz = 1.1 kHz away, which is what you are reporting.
>>
>> Remember that RX SHFT is a "per-band" setting, so you need to enable it
>> separately for each band.
>>
>> 73,
>> Matt VK2RQ
>>
>> > On 16 Feb 2015, at 12:17 pm, David Orman <ormandj at corenode.com> wrote:
>> >
>> > Hi,
>> >
>> > I've been performing all of the "All-Band Receive Opposite Sideband and
>> > I.F. Image Nulling" steps without issue using my PX3 (and AA-54) as a
>> > signal generator. I'm at the last section, "RX SHFT=8.0 I.F. Image (16
>> kHz)
>> > Nulling", and am having trouble. Following the directions, and setting
>> my
>> > KX3 16KHz up from the signal source:
>> >
>> > 7. Optimize RX SHFT=8.0 I.F. image gain and phase settings as follows:
>> a.
>> > Set both the signal source and KX3 to the target band (starting with 160
>> > m). Recall that the VFO should be set 16 kHz higher than the signal
>> source.
>> > Make sure you’re in CW mode. (Note: You can change bands and modes from
>> > within the RXSBNUL menu entry.) You should hear a strong signal, and
>> see an
>> > Smeter reading of between S9 and S9+30 dB. If not, adjust the preamp
>> > setting or the RF source level.
>> >
>> > This step, I do _not_ hear a strong signal, I hear no signal at all. If
>> I
>> > turn on RIT to -1.1, I hear a strong signal (looking at the next step.)
>> >
>> > What am I doing wrong/missing?
>> >
>> > Thank you,
>> > David
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