Date   

I/Q Correction Error

 

Simon or anyone.
I have this set of signals independent of the tuning frequency. Could it be I/Q correction not quite right?

Two attached images are 1 gHz apart but identical.  Same set of signals up and down the tuning range always in the center of the Spectrum display


Setup is:
HackRF - I have two both with the same output

Antenna - Terminated in a 50 ohm load

Windows 10

SDR Console - V3 latest version


Is there a fix?



Re: LimeSDR Update - Good!

Siegfried Jackstien
 

let me do an educated guess ... he unsoldered that one coil (that we had a few posts before) in parallel to the one input transformer ... (it short circuits low end signals) ...

if you live to a stron local mw station ... then you should add a notch filter for that station ... or for the whole mw band

otherwise these strong station(s) may mask out lower signals

dg9bfc sigi


Am 12.02.2017 um 13:23 schrieb malet-bernard@... [sdr-radio-com]:

 
Simon,
You who have the LimeSDR 1.4 can you, please make a screenshot to see the signal of all the Long Wave transmitters.from home
Range 100 KHz to 300 KHz
Tell me with what type of antenna you receive this low band
What modification have you made?
Thank you in advance for your help 
Berenard
 


Re: LimeSDR Update - Good!

Bernard Malet
 

Simon,
You who have the LimeSDR 1.4 can you, please make a screenshot to see the signal of all the Long Wave transmitters.from home
Range 100 KHz to 300 KHz
Tell me with what type of antenna you receive this low band
What modification have you made?
Thank you in advance for your help 
Berenard
 


Re: Thetis and new firmware re Anan 10EE

Jim Bentley
 

Hi Simon,
            Thanks I'll look forward to receiving it.

73's Jim G4JIX 


Re: I/Q Cancellation problem with HackRF

Simon Brown
 

OK,

 

I now have time to breath. If you look at your screenshots you don’t see a single spike, rather a group. DC correction removes only a single ‘spur’ in the center caused by the average of I and Q not being zero.

 

There are reasons why other software may not show this:

 

  • More advanced IQ correction,
  • FFT settings which reduce the amount of data being processed, as a result very fine detail is lost,
  • Windowing applied to the FFT data,
  • You’re using the enhanced resolution in the SDR Console waterfall.

 

Anyway, what I’m slowing getting at is these multiple lines aren’t caused by DC imbalance as far as I can see, I’m sure they are coming from the hardware. I am applying standard DC imbalance correction where I continually compute the average I and Q and apply this as a correction. I haven’t used my HackRF in a few years, I can connect it up and give it a go.

 

FWIW the LimeSDR removes a single, central spur superbly but does currently have issues with mirroring which I hope they’ll correct in a future firmware upgrade.

 

Simon Brown, G4ELI
http://sdr-radio.com

 

From: sdr-radio-com@... [mailto:sdr-radio-com@...]
Sent: 12 February 2017 00:50
To: sdr-radio-com@...
Cc: Simon Brown
Subject: [sdr-radio-com] I/Q Cancellation problem with HackRF

 

 

Simon and all.
The problem I am having is shown on my web site here:


Re: I/Q Cancellation problem with HackRF

Simon Brown
 

Hi,

 

Please attach the screenshots to the post, it makes life much easier J .

 

Simon Brown, G4ELI
http://sdr-radio.com

 

From: sdr-radio-com@... [mailto:sdr-radio-com@...]
Sent: 12 February 2017 00:55
To: sdr-radio-com@...
Cc: Simon Brown
Subject: [sdr-radio-com] I/Q Cancellation problem with HackRF

 

 

The problem I am seeing is shown on my web site Her:
http://www.seti.net/engineering/engineering.php

I have posted two screen grabs of SDR Console operating 1 gHz apart and also a WAV file captured from SDR Console.
I see this same set of signals in the center of the Spectrum Display regardless of setup of either of my two HackRF receivers.

Download the file and change its name extension to .WAV to play it back.
Any ideas?

Regards...... Jim


Re: LimeSDR Update - Good!

Simon Brown
 

It does seem to be working quite well now.

 

Simon Brown, G4ELI
http://sdr-radio.com

 

From: sdr-radio-com@... [mailto:sdr-radio-com@...]
Sent: 12 February 2017 03:06
To: sdr-radio-com@...
Subject: Re: [sdr-radio-com] Re: LimeSDR Update - Good!

 

 

me too Andy, but the brave scouts before us most likely saved a lot of aggravation. Thank god for Simon Brown's SDR Console and Paul and the fellow who found the thingy to remove.

I only LimeSDR folk amend the next batch so that the second wave of purchaser's will not have to modify their board!!!!!!


Vincent


Re: LimeSDR Update - Good!

vincent
 

me too Andy, but the brave scouts before us most likely saved a lot of aggravation. Thank god for Simon Brown's SDR Console and Paul and the fellow who found the thingy to remove.
I only LimeSDR folk amend the next batch so that the second wave of purchaser's will not have to modify their board!!!!!!

Vincent


Re: LimeSDR Update - Good!

Andrew O'Brien <k3ukandy@...>
 

Reading all this is making forget the regret I had for not ordering one last year.
Andy K3UK

On Sat, Feb 11, 2017 at 9:24 PM, Paul Jones paul@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 

Doug. Correct, at first I thought it was the larger ferrite/coil, that could have been a costly mistake

Paul Jones - NN4F
Ridgeville, SC EM93TB

Email: paul@...
Facebook.com/groups/sdrplay




On Sat, Feb 11, 2017 at 5:58 PM, Doug dmcgarrett@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 



On 02/11/2017 05:27 PM, MV Elttba altectogo@... [sdr-radio-com] wrote:
 
Thanks Paul. maybe the Lime guys will remedy this in the next production run?

Vincent

On Sat, Feb 11, 2017 at 2:11 PM, Paul Jones paul@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 
Make sure you take the right thing off, someone thought it was the coil you could see, is a smt coil
See image for location, it was me, I just pushed on it with my nail and it came off.... MN18 is the part, it will leave the two solder pads...

Paul - NN4F




Paul Jones - NN4F
Ridgeville, SC EM93TB

Email: paul@...
Facebook.com/groups/sdrplay

Perhaps it confuses people to call it a "coil"—they might be looking for a physical coil. Call it an inductor.

--doug, retired RF Engineer




On Sat, Feb 11, 2017 at 4:21 PM, Siegfried Jackstien siegfried.jackstien@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 

as already noted ... it is just removing a coil

on the lime hp some user reported it is an easy fix

a user wrote that the coil just "ppped olff" when he touched it

but i am guessing that is seldom ... so fire up your soldering iron and use a good magnifier

then desoldering should be easy

(sadly i do not own a lime ... so can not say more details ... but that is what i read somewhere else)

dg9bfc sigi


Am 11.02.2017 um 20:33 schrieb MV Elttba altectogo@... [sdr-radio-com]:
 
So Simon, how hard is it to take the transformer out? Should the Lime guys do this and not the customer?

Vincent




--
Blessed are the peacemakers...for they shall be shot at from both sides.--A.M,Greeley




Re: LimeSDR Update - Good!

Paul NN4F
 

Doug. Correct, at first I thought it was the larger ferrite/coil, that could have been a costly mistake

Paul Jones - NN4F
Ridgeville, SC EM93TB

Email: paul@...
Facebook.com/groups/sdrplay




On Sat, Feb 11, 2017 at 5:58 PM, Doug dmcgarrett@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 



On 02/11/2017 05:27 PM, MV Elttba altectogo@... [sdr-radio-com] wrote:
 
Thanks Paul. maybe the Lime guys will remedy this in the next production run?

Vincent

On Sat, Feb 11, 2017 at 2:11 PM, Paul Jones paul@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 
Make sure you take the right thing off, someone thought it was the coil you could see, is a smt coil
See image for location, it was me, I just pushed on it with my nail and it came off.... MN18 is the part, it will leave the two solder pads...

Paul - NN4F




Paul Jones - NN4F
Ridgeville, SC EM93TB

Email: paul@...
Facebook.com/groups/sdrplay

Perhaps it confuses people to call it a "coil"—they might be looking for a physical coil. Call it an inductor.

--doug, retired RF Engineer




On Sat, Feb 11, 2017 at 4:21 PM, Siegfried Jackstien siegfried.jackstien@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 

as already noted ... it is just removing a coil

on the lime hp some user reported it is an easy fix

a user wrote that the coil just "ppped olff" when he touched it

but i am guessing that is seldom ... so fire up your soldering iron and use a good magnifier

then desoldering should be easy

(sadly i do not own a lime ... so can not say more details ... but that is what i read somewhere else)

dg9bfc sigi


Am 11.02.2017 um 20:33 schrieb MV Elttba altectogo@... [sdr-radio-com]:
 
So Simon, how hard is it to take the transformer out? Should the Lime guys do this and not the customer?

Vincent




--
Blessed are the peacemakers...for they shall be shot at from both sides.--A.M,Greeley



I/Q Cancellation problem with HackRF

 

The problem I am seeing is shown on my web site Her:
http://www.seti.net/engineering/engineering.php
I have posted two screen grabs of SDR Console operating 1 gHz apart and also a WAV file captured from SDR Console.
I see this same set of signals in the center of the Spectrum Display regardless of setup of either of my two HackRF receivers.
Download the file and change its name extension to .WAV to play it back.
Any ideas?
Regards...... Jim


I/Q Cancellation problem with HackRF

 

Simon and all.
The problem I am having is shown on my web site here:


Re: LimeSDR Update - Good!

doug
 



On 02/11/2017 05:27 PM, MV Elttba altectogo@... [sdr-radio-com] wrote:
 
Thanks Paul. maybe the Lime guys will remedy this in the next production run?

Vincent

On Sat, Feb 11, 2017 at 2:11 PM, Paul Jones paul@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 
Make sure you take the right thing off, someone thought it was the coil you could see, is a smt coil
See image for location, it was me, I just pushed on it with my nail and it came off.... MN18 is the part, it will leave the two solder pads...

Paul - NN4F




Paul Jones - NN4F
Ridgeville, SC EM93TB

Email: paul@...
Facebook.com/groups/sdrplay

Perhaps it confuses people to call it a "coil"—they might be looking for a physical coil. Call it an inductor.

--doug, retired RF Engineer




On Sat, Feb 11, 2017 at 4:21 PM, Siegfried Jackstien siegfried.jackstien@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 

as already noted ... it is just removing a coil

on the lime hp some user reported it is an easy fix

a user wrote that the coil just "ppped olff" when he touched it

but i am guessing that is seldom ... so fire up your soldering iron and use a good magnifier

then desoldering should be easy

(sadly i do not own a lime ... so can not say more details ... but that is what i read somewhere else)

dg9bfc sigi


Am 11.02.2017 um 20:33 schrieb MV Elttba altectogo@... [sdr-radio-com]:
 
So Simon, how hard is it to take the transformer out? Should the Lime guys do this and not the customer?

Vincent




-- 
Blessed are the peacemakers...for they shall be shot at from both sides.--A.M,Greeley


Re: LimeSDR Update - Good!

vincent
 

Thanks Paul. maybe the Lime guys will remedy this in the next production run?

Vincent

On Sat, Feb 11, 2017 at 2:11 PM, Paul Jones paul@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 

Make sure you take the right thing off, someone thought it was the coil you could see, is a smt coil
See image for location, it was me, I just pushed on it with my nail and it came off.... MN18 is the part, it will leave the two solder pads...

Paul - NN4F




Paul Jones - NN4F
Ridgeville, SC EM93TB

Email: paul@...
Facebook.com/groups/sdrplay




On Sat, Feb 11, 2017 at 4:21 PM, Siegfried Jackstien siegfried.jackstien@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 

as already noted ... it is just removing a coil

on the lime hp some user reported it is an easy fix

a user wrote that the coil just "ppped olff" when he touched it

but i am guessing that is seldom ... so fire up your soldering iron and use a good magnifier

then desoldering should be easy

(sadly i do not own a lime ... so can not say more details ... but that is what i read somewhere else)

dg9bfc sigi


Am 11.02.2017 um 20:33 schrieb MV Elttba altectogo@... [sdr-radio-com]:
 
So Simon, how hard is it to take the transformer out? Should the Lime guys do this and not the customer?

Vincent




Re: LimeSDR Update - Good!

vincent
 

then how difficult is it to remove it?

Vincent

On Sat, Feb 11, 2017 at 12:40 PM, MIKE DURKIN Patriot121@... [sdr-radio-com] <sdr-radio-com@...> wrote:
 

It's not the transformer thats the problem but a low value inductor across the I/Q lines that are next to the transformer....



Get Outlook for Android



From: sdr-radio-com@... <sdr-radio-com@...> on behalf of MV Elttba altectogo@... [sdr-radio-com] <sdr-radio-com@...>
Sent: Saturday, February 11, 2017 12:33:15 PM
To: sdr-radio-com@...
Subject: [sdr-radio-com] Re: LimeSDR Update - Good!
 
 

So Simon, how hard is it to take the transformer out? Should the Lime guys do this and not the customer?

Vincent



Re: LimeSDR Update - Good!

Paul NN4F
 

Make sure you take the right thing off, someone thought it was the coil you could see, is a smt coil
See image for location, it was me, I just pushed on it with my nail and it came off.... MN18 is the part, it will leave the two solder pads...

Paul - NN4F




Paul Jones - NN4F
Ridgeville, SC EM93TB

Email: paul@...
Facebook.com/groups/sdrplay




On Sat, Feb 11, 2017 at 4:21 PM, Siegfried Jackstien siegfried.jackstien@... [sdr-radio-com] <sdr-radio-com@...> wrote:

 

as already noted ... it is just removing a coil

on the lime hp some user reported it is an easy fix

a user wrote that the coil just "ppped olff" when he touched it

but i am guessing that is seldom ... so fire up your soldering iron and use a good magnifier

then desoldering should be easy

(sadly i do not own a lime ... so can not say more details ... but that is what i read somewhere else)

dg9bfc sigi


Am 11.02.2017 um 20:33 schrieb MV Elttba altectogo@... [sdr-radio-com]:
 
So Simon, how hard is it to take the transformer out? Should the Lime guys do this and not the customer?

Vincent



Re: Pluto

Siegfried Jackstien
 

another hint

i use a c band lnb for receiving 3.4 gig (has a lo of 5150 megs)

so ... with a sup 2400 ... and a c band lnb you can have a very wide band sdr setup

with low end use the sdr alne

mid area use sup2400

high area use c band lnb

....

and for 10 gig use a modded ku band lnb :-)

dg9bfc sigi


Am 11.02.2017 um 20:07 schrieb Joe Puma theprogramllc@... [sdr-radio-com]:

 
I already have two sup2400's. I attempted to mod the first one, it seemed to work but something was still wrong or off.  I wasn't sure if I did something wrong with the mod but I was gonna give it another shot, maybe have someone do the mod for me. I still have one virgin sup2400 if anyone is interested :)

Joe

Sent from my iPhone

On Feb 11, 2017, at 2:43 PM, Henk van Roon vanroonhenk@... [sdr-radio-com] <sdr-radio-com@...> wrote:

 

buy a dongel with a downconvertor. Goes up to 4.5 GHz,   http://www.rtl-sdr.com/receive-up-to-4-5-ghz-on-your-rtl-sdr-for-5-using-a-directv-downconverter/


Op 11-2-2017 om 19:48 schreef Joe Puma theprogramllc@... [sdr-radio-com]:
 
What's the bandwidth? I'm looking for something that will let me look at the entire 2.4ghz spectrum. 


Sent from my iPhone

On Feb 11, 2017, at 4:55 AM, Siegfried Jackstien siegfried.jackstien@... [sdr-radio-com] <sdr-radio-com@...> wrote:

 

makes sense

uhf and above

70cm

23cm

13cm

9cm

makes 4 hambands

plus

1090megs (air-planes)

1.5 gig (inmarsat)

etc etc

i would use an upconverter (400 megs clock) for all bands below 300 megs

dg9bfc sigi

ps i would like to have a tv receiver app (analog AND digital tv) for it


Am 10.02.2017 um 23:09 schrieb Henk van Roon vanroonhenk@... [sdr-radio-com]:
 

FROM from 325 to 3800 MHz, MAKES NO SENce to me


Op 10-2-2017 om 23:30 schreef MV Elttba altectogo@... [sdr-radio-com]:
 
looks like a toy

Vincent





Re: LimeSDR Update - Good!

Siegfried Jackstien
 

as already noted ... it is just removing a coil

on the lime hp some user reported it is an easy fix

a user wrote that the coil just "ppped olff" when he touched it

but i am guessing that is seldom ... so fire up your soldering iron and use a good magnifier

then desoldering should be easy

(sadly i do not own a lime ... so can not say more details ... but that is what i read somewhere else)

dg9bfc sigi


Am 11.02.2017 um 20:33 schrieb MV Elttba altectogo@... [sdr-radio-com]:

 
So Simon, how hard is it to take the transformer out? Should the Lime guys do this and not the customer?

Vincent


Re: LimeSDR Update - Good!

Simon Brown
 

Vincent,

 

Not sure J

 

Simon Brown, G4ELI
http://sdr-radio.com

 

From: sdr-radio-com@... [mailto:sdr-radio-com@...]
Sent: 11 February 2017 20:33
To: sdr-radio-com@...
Subject: [sdr-radio-com] Re: LimeSDR Update - Good!

 

 

So Simon, how hard is it to take the transformer out? Should the Lime guys do this and not the customer?


Vincent


Re: LimeSDR Update - Good!

MIKE DURKIN <Patriot121@...>
 

It's not the transformer thats the problem but a low value inductor across the I/Q lines that are next to the transformer....



Get Outlook for Android



From: sdr-radio-com@... on behalf of MV Elttba altectogo@... [sdr-radio-com]
Sent: Saturday, February 11, 2017 12:33:15 PM
To: sdr-radio-com@...
Subject: [sdr-radio-com] Re: LimeSDR Update - Good!
 
 

So Simon, how hard is it to take the transformer out? Should the Lime guys do this and not the customer?

Vincent