NN4ZZ CwSkimmer and SDR-Bridge setup – A quick start guide
Revision History
14-Jun-2014 - added Telnet screen
11-Aug-2014 - added additional notes about SmartCat and DAX control panel
20-Jan-2015 - update version numbers and added troubleshooting notes
21-Jan-2015 - Added troubleshooting note about BLIND mode
6-Feb-2015 - Added “contents”, added screen shots, reorganized9-Feb-2015 - Added notes about the Reverse Beacon Network
15-Feb-2015 - update SDR-Bridge version, additional troubleshooting notes
15-Mar-2015 – Added SDR-Bridge setup screen, note on skimmer audio tab
17-Mar-2015 – Added notes for SSDR V1.4 changes
11-Apr-2015 – Added “output sample rate” error note
18-Feb-2016 – Added new version info and more troubleshooting tips
25-Mar-2017 – Added CW Skimmer Left/right channel troubleshooting tip
7-Jun-2017 - Added RBN setup notes from Andy / KU7T
6-Dec-2018 – Added flow diagram
18-Feb-2020 – Added channel bandwidth troubleshooting tip
19-Feb-2020 – Added weak decoding outside band troubleshooting tip

Table of Contents Document Overview – Page 2 Version information for all programs – Page 4
 Download information for CW Skimmer – Page 5
 Download information and setup for SDR-Bridge – Page 6
 SmartCat information - Page 8
 SmartSDR and DAX setup information – Pages 9 & 10
 Setup information for CW Skimmer – Pages 12
 Using SDR-Bridge – Page 15
 Typical CW Skimmer screen shot – Page 16
 Troubleshooting notes – Pages 17
 Reverse Beacon Network - How to use the SDR-Bridge – Pages 31

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Document Overview
This goal for this document is to help you get started with the CW Skimmer and SDRBridge setup. The capabilities of each program are extensive, this document will not
attempt to address all of them. It is recommended that you start by getting just one
instance of CW skimmer running with SDR-Bridge and then explore the possibilities
and capabilities of each program. The setup is not difficult but there are a number ofminor things than can cause problems. In addition to the recommended settings foreach program, there is a troubleshooting section that can help if you run intodifficulty.
Regards, Al / NN4ZZ - email: Al (at) nn4zz (dot) comPage | 2

Simplified data flow diagram

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Version information for SDR-Bridge, DAX control panel and CWSkimmer.

 CW Skimmer – Version 1.8.3 or later (currently 2.1)
 SDR-Bridge – Version 1.5.0 or later (currently 1.6.4)
 SmartSDR - Version 1.3.8.126 or later
 DAX Control - Version 1.3.8.126 or later

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CwSkimmer

Down load and install the latest version of CwSkimmer into the default directory.

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SDR-Bridge
Down load and install SDR-Bridge from:http://www.qrv.com/sdrbridge.html

Page | 6Note: The Telnet port in CW Skimmer must match the port shown here. For example IQ1 is 7310. See the CW Skimmer
telnet port setup later in the document. NOTE: If you are using to feed the Reverse Beacon Network, see the notes
starting on page 28 regarding the ports and call setup

If you need to reset the values in this screen to the defaults, the process is described in the troubleshooting section.

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SmartCat
SmartCat is not needed any longer for CW Skimmer when using SDR-Bridge. Ifyou previously used it before SDR-Bridge, it is no longer necessary to setup adedicated port for OmniRig. SDR-Bridge connects directly to the radio. If youhave a port setup, you can delete it. In fact you don’t even have to start SSDR
SmartCAT unless you need it for another reason.

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SmartSDR
Set the DAXIQ channel.
Note: The DAX settings in the SLICE are not used for CW Skimmer, only the DAX IQ
setting on the left side of the SSDR screen is used.

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DAX control panel
The control panel should look like this:Page | 10

The only DAX setup needed for CW Skimmer is the IQ stream. To enable theDAXIQ channel, click the button for the channel you are using to ENABLE thechannel, it should turn BLUE. Set the Sample rate to 96000. Note: if you areusing CWS to feed the Reverse Beacon Network see notes starting on page 28
about the sampling rate.
Note about the FREQUENCY displayed in the DAX control panel. It is the center
frequency of the PANADAPTER, not the frequency of the slice receiver.

Starting in DAX V1.4 the RATE:value is replace with the word “Streaming” when running. You can see the rate byhovering the cursor.

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CW Skimmer Setup
Radio – SoftRock, Sampling 96KHZ, CW Pitch to match SmartSDRRADIO Tab

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Audio settings – your DAX IQ device may be named slightly different.

Note: Do NOT set the Audio I/O device to the same device as the Signal I/O device.
This will cause issues. It should be set to one of your PC audio playback devices.

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Telnet screen

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Using SDR-Bridge
Snapshot shows 4 CW skimmers set up. Start your testing with just one.
Select IQ1, select a slice (e.g. Slice A), check the SKIM box to start up a skimmer
session.

NOTE: There are options on the Radio and Skimmer tabs that affect how the program
operates. Also starting V1.1.1 there are options you can set by RIGHT clicking on thefrequency. To get started you can just use the defaults. Review the official SDR-Bridge
doumentation to see what works best for the way you operate.

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CW Skimmer screen during K1N DXPedition.

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Troubleshooting notes:- Verify the versions of SDR-Bridge, CW Skimmer, and DAX control panel. Itis easy to get an older copy loaded that will probably not work. It’s also easy
to launch an older copy since you may have multiple versions on your PC.
- Don’t start up CW Skimmer from a shortcut. Let SDR-Bridge start up CW
Skimmer when it starts. Otherwise you can have multiple copies and some
confusion.

- If there is no data being sent to CW Skimmer, check to be sure the DAX IQ
channel is set.

- Sometimes the CW Skimmer instance needs to be manually closed and reopened to start working. It may even be hard to close (give errors) and haveto be stopped with the task manager. Usually after closing the skimmer itwill start up normally from the check box in SDR-Bridge.

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- Win 10 users – it has been reported in one case SDR-Bridge and CWS were
working fine but stopped transferring IQ data on just one of the IQ channels.
After much checking no cause was found but a PC reboot corrected the issue.
- If rebooting doesn’t fix the flaky channel problem, another option is to change
to another channel. For example if you are using DAXIQ1 then try 2 or 3.
You have to set that in 3 places. Select the DAXIQ channel in the SSDRscreen, enable the channel in the DAX control panel, Activate the skimmer
with the slice desired in the IQ option on the SDR-Bridge “Bridge” tab.

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- Sometimes CW Skimmer will not start from the check box in SSDR. Or theskimmer may come up with a black screen or otherwise error out. In thiscase you can manually start one (or more instances) of CW Skimmer before
launching SDR-Bridge by using one of the shortcuts provided here:
By using one of the shortcuts Ed provides it will start up using the correct
IQx.ini file. Here is where they are located. You can copy and paste them tothe desktop for quick access.

- If skimmer is up but not displaying the calls and other data, be sure to check
the TELNET settings tab on CW Skimmer. Be sure they match the telnet
settings in SDR-Bridge. Also check program versions.

- If the SDR-Bridge settings are wrong, or get set wrong, you can reset them tothe defaults by doing the following. To restore default settings, delete thecontents of [user]\appdata\local\w2rf.

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- If the skimmer frequency is slightly off from the slice receiver, check to see if
your CW Skimmer CW Pitch matches the pitch setting in SmartSDR. Be
aware that Skimmer currently may be off a bit due to the granularity forsynching. This will be corrected in a future version of CW Skimmer.
- Sometime the Skimmer does not display the same frequency data as yourslice receiver. You can often re-synch them by shaking the slice receiver.
(click and hold in the panadapter and move side to side)- Sometime the Skimmer .ini file get corrupted by changing settings. If you
suspect this is the problem you can overwrite them with a fresh copy the Edprovides. See the snapshot below to show where to get the fresh copy andwhere to paste it to overwrite the corrupted copy.

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Page | 21

- If CW Skimmer is displaying but it looks bad, check to verify that the sample
rate in the DAX Control panel isn’t set to 48,000.

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-If your CW Skimmer screen doesn’t show the call information or decoded text you may have accidently ENABLED
BLIND mode. You will see the frequency displayed, the code steam, and the “dots” but NO text.
BLIND MODE = ON

BLIND MODE = OFF

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- There are some new options for working split on SDR-Bridge starting in V1.1.1. If you
notice some things like muting or TX Active working differently, take a look at the newoptions to see if you need to makes changes for your operating style.

The changes are on the BRIDGE tab and the RADIO tab.

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- When CW Skimmer starts up you get this continuously repeating error: Output sample
rate out of range.
Check the CW Skimmer Audio I/O Device on the Audio tab of the CW Skimmer settings.
It should NOT be set to the same device as listed in the Signal I/O Device. Typically it is
set to your audio output device but you may have to try some other settings.

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- Several users of CW Skimmer have reported that the following error message appears
on program startup:"Access violation at address 00404DD3 in module CwSkimmer.exe. Read of address00000000."

The error occurs only on those systems where the Skimmer was installed using a regularuser account on Windows, with standard privileges. The installer has to put some
executable files in the Program Files folder, and some data files in the user data folder.
Since the regular users are not allowed to write to Program Files, the installer runs as
Administrator. As a result, the data files are placed in the administrator’s data folder,
not in the user's folder. This is how MS designed their security system, and this cannot
be bypassed.
To fix the problem, log in as Administrator and copy the data files from admin's folder toyour user's folder. For example, if your admin name is AlexAdmin, and your regular username is AlexUser, then you copy all files from this directory
C:\Users\AlexAdmin\AppData\Roaming\Afreet\Reference
to this one:
C:\Users\AlexUser\AppData\Roaming\Afreet\Reference

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Chuck / W9WLX reported this issue. All frequencies sync and follow--the slicereceiver, SDR Bridge and the TX frequency on CW Skimmer. If I set the TX frequency onskimmer to the center frequency of the DAX IQ stream, it works as expected. However,
if I change the slice frequency, off the center stream frequency, it shifts in the opposite
direction. For example, if my center stream frequency is 7.020 and I double click on astation at 7.022 on the Skimmer waterfall, the slice receiver will follow and go to 7.022,
however the station is really at 7.018.
The problem was the “left / right” channel was set up incorrectly in the CQ Skimmer
Audio panel. It should be set to I / Q.

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George / K3GBB reported the skimmer display was not showing the fullbandwidth shown on the SSDR screen. Note in the snapshot below signals
below 14.054 do not display on the skimmer screen.

The problem was the DAXIQ bandwidth setting in Windows. It shoud be
192000 hz and was set to a lower value. Open the Sound Control Panel.
For the active DAX IQ and RESERVED DAX IQ devices make sure BOTH
are set to 192khz.

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Problem – Skimmer shows some spots that looks like dupliates. This issue noted by Ed / W2RF -- This problem

happens when users have DAX IQ channels that are covering out of band frequencies. This happens mostoften with 192khz, but can happen with others if the center of the panadapter is near the band edge. The Flex
produces very weak images outside the band, especially in WIDE mode. However CW Skimmer is sensitive
enough to pick them up. So you get out of band spots, that look like duplicates of an in band spot. (So thesymptom looks a lot like a wrong sample rate setting, but it isn’t.)
There are several things you can do to avoid this.
1 - One is to have calls verified by the master dta file, but it only contains the calls of contesters.
2 - Another helpful thing is to make sure the noise blanker is on. It’s the first blue icon on the option bar. (Ialso always make sure the key click filter, the second blue icon, is on.)3 - But the best solution is to select a band plan and tell it to only skim in band:

Finally, since there is some tailoring of the INI file, once they get everything the way they want it users mightfind it useful to back them up from Program Data/W2RF.

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Reverse Beacon Network – works with SDR-Bridge
If you aren’t familiar with the Reverse Beacon Network see the link on the next page for ashort history.

The aggregator softwareThis software receives spots from CW Skimmer or Skimmer Server's telnet port, and sends the spots to the Reverse
Beacon Network.

rbn_aggregator_v3.0.exe
Microsoft .NET framework version 4 must be installed

For more information about using the RBN aggregator, please read:Using Aggregator 10.pdf
The following notes provided by Tom WQ5O and he reports that is it working fine.



Load the SDR-Bridge first, and setup 4 slices. Then started the aggregator. In the Secondary Skimmer box in theaggregator insure the ports in the aggregator match the ports for the different slices in Bridge. Click "connectskimmer" for each slice and it will connect. The primary skimmer also connected when I started aggregator.
You have to check the DAX control panel to insure you're running 96K for the IQs. A - 96K, IQ1; B - 96K, IQ2, etc.
There is a place in the aggregator to add your call sign for each skimmer so that it'll show correctly in theRBnetwork. It also seems to adjust the frequency offset automatically when you get the entire thing set up.

It's not hard to set up but there are several steps that you have to make sure are correct or the skimmers won't display
the correct info. The DAX IQs have to match the correct slices in the different skimmers. The DAX IQs have to be set at
96K or the skimmers won't display the correct info.
They SDR-Bridge and Reverse Beacon Aggregator work well together from what I see. I had 4 skimmers runningyesterday most of the day and they produced a lot of traffic for the RBN.

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Here is a screen shot of the RBN and some additional information on the RBN
Click link for the WELCOME page of the Reverse Beacon Network
http://www.reversebeacon.net/index.php
Click link for a short history of the Reverse Beacon Network.
http://www.reversebeacon.net/pages/A+Short+History+12

Typical DX screen with a filter applied for the recent K1N DXpedition.

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These RBN setup notes below were provided by Andy / KU7T

The host and port settings in SDRBridge need to point to the CWSkimmer port. If you do run
both the bridge and CWSkimmer on the same PC, then the settings should be “localhost” and“some port”. That port needs to match. The call in the SDRBridge can be anything, but it
cannot have any special characters in it. For example do not use KU7T-1. Suggestion is to use
your legal licensed call.

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In CWSkimmer, “Allow skimmer commands” needs to be checked.

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The call sign in the CW skimmer dialog will be the call sign of the station that the spots will beoriginating. In most cases, this will also be your own valid call sign. (In some rare cases, you
may want to add a /call area, i.e. KU7T/7, if there is already another skimmer online with thebase call sign.)

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By doing this, you can recognize your own spots in your logging software.

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(optional) You can also send your local spots to the RBN network for others to use. In this caseyou use the RBN aggregator to send the spots out, and then connect to your favorite cluster
node which would then get you the spots back (with all the others). If you wanted to do that,you need to download the latest RBN aggregator software from www.reversebeacon.net, andconfigure it to connect to your local CW Skimmer. One or multiple (up to 8 skimmers aresupported). In order to do that, the Aggregators setting must point to the CW Skimmer, IPAddress and Port. The call sign again must be your legal call sign.

(optional) If you want to feed your logger with your locally skimmed spots AND a public cluster(but not send your spots to RBN), you need to combine these two feeds. A suggested tool is
K1TTT’s WintelnetX tool. You can think of it as a Y “connection” for cluster feeds. For example,
you could connect to both VE7CC AND your local CW Skimmer feed, and output it on a local
port. That port you would then connect your favorite logging program to it. (see screen shotabove).

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A good help for troubleshooting: In the status bar at the lower right corner of CW Skimmer
you can see how many telnet users are connected. There must be at least 1 telnet user forSDRBridge. If you do not see 1 connected for the bridge, the settings in the bridge do notmatch. In case of you using RBN Aggregator (option 3), a second user will be connected for it.
Or, if you just use the spots locally (option 3) you should also see a second user connected toit. There is no limit of how many telnet clients can connect to the CW Skimmer.

Note: It is also possible to both combine the feeds and send to RBN (options 2 and 3). In thatcase, a contester may have an advantage of getting the raw local spots without any filtering ordelay from the RBN network. In that example, 3 telnet users would be connected.
SAMPLING RATE: I am able to run with 192khz sample rate, and therefore have more bandcoverage. As long as DAX and CW Skimmer are set to it, works fine. This is good because it
seems the center frequency could be arbitrarily at the beginning of the band, i.e. 7.012, and if
using 96 would only give me coverage to about 7.012 + 48. With 192, the whole band iscovered…

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