Hello K3 fans
I am a bit stranged and frustrated cause nobody has answered a single
word to my email K3 RX spurs posted on november the 20th. No comments,
no ideas
After some tests I have concluded that the spurs are 3rd order
intermodulation products. They only occur in DATA or CW.
¿Can
What output are you taking the audio from to plot these results? The line
output signal goes through an isolating transformer. I think this saturates
at quite a low audio level introducing non-linearity. You need to turn LIN
OUT down to 2 or as low as you can get.
I haven't done the test you
Hi Julian
I am very glad to see that someone has replyied to my email.
I have LINE_OUT= nor 019
If I go down to 002 I need to rise gain at the sound card, and the
intermods are the same.
http://ea1abz.ure.es/spurs.jpeg
This spurs seem to produce only if both test signals are close, closer
Is this about 3rd order inband IMD? The subject was widely discussed some
time ago. Just try to search the archaive.
73, Igor UA9DC
- Original Message -
From: Ramiro Aceves ea1...@gmail.com
To: elecraft@mailman.qth.net
Sent: Tuesday, November 23, 2010 3:20 PM
Subject: [Elecraft] K3 RX
, but I have not found IMD measurements made
with very closed test sigs.
73, Ramiro.
EA4NZ
73, Igor UA9DC
- Original Message - From: Ramiro Aceves ea1...@gmail.com
To: elecraft@mailman.qth.net
Sent: Tuesday, November 23, 2010 3:20 PM
Subject: [Elecraft] K3 RX spurs
Hello K3
Ramiro,
Are you using a hybrid to combine the SW carrier and the signal generator's
output before sending them to the K3, and how strong are these two signals
(dbm)?
If you are not using some type of hybrid, could you please let me know how
you are adding these signals.
It is possible that
For comparison, sigs of FT-897 and K3. Notice the increase in IMD on
DATA mode. FT-897 and K3 on USB have got similar IMD.
http://ea1abz.ure.es/k3_vs_ft897.jpeg
I have seen worst IMDs but I have not registered them
73, Ramiro.
__
A more evident difference in IMD between DATA and USB modes.
http://ea1abz.ure.es/cw_vs_data.jpeg
Thanks,
Ramiro, EA4NZ
__
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Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help:
Lyle Johnson escribió:
Hello Ramiro!
O, Yes, yess, yess
Lyle, you are a genius! I must go out home now, I will tell you later!!
It may be AGC pumping due to the close spaced signals having a beat note
that is slower than the AGC
Thank you. My suspicion is that the IMD is being generated outside of the
radios, but I need to take a closer look at your data.
I see that there are many more IMD products below 990 Hz than above 1000 Hz
in the top half of the waterfall in your CW vs DATA comparison, which could
suggest that
Ramiro
I don't see any difference here between USB, CW and Data. Third order
products are about 45-50dB down here, whereas yours seem to be about
20dB down (difficult to see on the spectrum though). Maybe your sound
card input is being over-driven?
Graham
On 19:59, Ramiro Aceves wrote:
@mailman.qth.net
Sent: Tuesday, November 23, 2010 5:55 PM
Subject: Re: [Elecraft] K3 RX spurs
Igor Sokolov escribió:
Is this about 3rd order inband IMD? The subject was widely discussed some
time ago. Just try to search the archaive.
Many information there, thanks
http
Thank you very much for all who reply to may problem and gave ideas and
suggestions.
http://ea1abz.ure.es/agcF-agcS.jpeg
Notice the 3rd order spur suppression after changing from AGC-F to AGS-S
settings in DATA A mode.
Igor, very interesting article, what a pitty that is in russian
Hi all,
I am going to describe a problem that I have found recently.
Several days ago, I was encouraged by another ham to see aircraft
doppler radio reflections. I wired my K3 to Linrad (www.sm5bsz.com) FFT
waterfall
Linux program. I tuned a spanish broadcast station on 21610 KHz (REE,
Radio
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