Date   

Re: Chasing ov

Rob Robinett
 

In Maui the Flamingo was not enough to suppress overloads from the 10 Km distant 5 KW 550 AM station.   A friend designed a custom replacement which suppresses 550AM by more than 60 dB while passing the 630M / 474 KHz band at about -6 dB..
But solving AM overload is easy compared to the problems of European sites who have many SW broadcast signals in the just above our 40M WSPR band.

On Fri, Oct 22, 2021 at 9:46 AM Rolf Ekstrand <rekstrand@...> wrote:
Greetings, y'all

I am now chasing ov events here.  Have installed the Flamingo - am bandpass filter, but seemingly still have some ov events around daybreak. The culprit are likely to be traced to two stations at 1560 and 1660.  In particular I suspect the last one as it switch from nighttime to daytime  transmitting power.  The station at 1660 is definitely the strongest  here both nighttime ( even behind the filter) and daytime and in looking at the Flamingo filter the attenuation is not that hot at that high end of the band. I guess I need to "cobble" together a  notch filter for 1660 and try that.   I also have a QRO DX hound 500 ft down the road that is many times taking advantage of the grey line propagation which is when these ov events so far can be traced to.  

I guess I have to keep trying to find out what cause these events. 

73  K9DZT   Rolf



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Chasing ov

Rolf Ekstrand
 

Greetings, y'all

I am now chasing ov events here.  Have installed the Flamingo - am bandpass filter, but seemingly still have some ov events around daybreak. The culprit are likely to be traced to two stations at 1560 and 1660.  In particular I suspect the last one as it switch from nighttime to daytime  transmitting power.  The station at 1660 is definitely the strongest  here both nighttime ( even behind the filter) and daytime and in looking at the Flamingo filter the attenuation is not that hot at that high end of the band. I guess I need to "cobble" together a  notch filter for 1660 and try that.   I also have a QRO DX hound 500 ft down the road that is many times taking advantage of the grey line propagation which is when these ov events so far can be traced to.  

I guess I have to keep trying to find out what cause these events. 

73  K9DZT   Rolf


How to see WD 2.10's log of overload events

Rob Robinett
 

I have recently become aware of how little many Kiwi users appreciate the importance of filtering the RF feed to a Kiwi so as to minimize RF overload events.

Each Kiwi receive job run by WD logs those events to a size-limited per-receive-channel file 'ov.log'.
You can see the list of those ov.log files sorted by time by executing this Linux command line:               ls -ltr $(find /tmp/wsprdaemon/ -name ov.log)
Each line of an ov.log  file consists of 2 or three fields:   

1) the time in epoch of the log entry   (epoch is seconds since Jan 1 1970)
2) the total number of ov events reported by the Kiwi since the WD listening session was started
and optionally:
3) the work PRINTED if the line was printed to the recording.log file in the same directory

Unless you have started WD at an elevated debug verbosity, those PRINTED ov.log lines won't be found in the  more human readable 'recording.log' file,.  And you don't want to run WD at an elevated verbosity level or the resulting log files will soon overflow your /tmp/wsprdaemon/... file system.  (That limitation is fixed in WD 3.0)

Running "ls -ltr $(find /tmp/wsprdaemon/ -name ov.log)"  will give a list of ov.log files like this:

oe9ghv@radiohill-wspr:~$ ls -ltr $(find /tmp/wsprdaemon/ -name ov.log)
......
-rw-r--r-- 1 oe9ghv oe9ghv 1939 Oct 19 14:26 /tmp/wsprdaemon/recording.d/KIWI_2/60/ov.log
-rw-r--r-- 1 oe9ghv oe9ghv   12 Oct 19 16:45 /tmp/wsprdaemon/recording.d/KIWI_1/2200/ov.log
-rw-r--r-- 1 oe9ghv oe9ghv   12 Oct 19 16:45 /tmp/wsprdaemon/recording.d/KIWI_1/630/ov.log
-rw-r--r-- 1 oe9ghv oe9ghv   12 Oct 19 16:45 /tmp/wsprdaemon/recording.d/KIWI_5/630/ov.log
-rw-r--r-- 1 oe9ghv oe9ghv   12 Oct 19 16:45 /tmp/wsprdaemon/recording.d/KIWI_3/12/ov.log
-rw-r--r-- 1 oe9ghv oe9ghv   25 Oct 19 16:45 /tmp/wsprdaemon/recording.d/KIWI_5/2200/ov.log
-rw-r--r-- 1 oe9ghv oe9ghv   25 Oct 19 16:45 /tmp/wsprdaemon/recording.d/KIWI_3/10/ov.log
-rw-r--r-- 1 oe9ghv oe9ghv 1883 Oct 19 19:47 /tmp/wsprdaemon/recording.d/KIWI_2/80/ov.log
-rw-r--r-- 1 oe9ghv oe9ghv 2042 Oct 19 19:47 /tmp/wsprdaemon/recording.d/KIWI_2/160/ov.log
-rw-r--r-- 1 oe9ghv oe9ghv 1970 Oct 19 19:47 /tmp/wsprdaemon/recording.d/KIWI_2/40/ov.log
oe9ghv@radiohill-wspr:

Looking at the lines at the ov.log file at the bottom of the list (the most recently written to) shows the raw file format described above:

oe9ghv@radiohill-wspr:/tmp/wsprdaemon/recording.d/KIWI_2/40$ tail -n 20 /tmp/wsprdaemon/recording.d/KIWI_2/40/ov.log ; echo
1634328773 846
1634328779 872
1634328784 892
1634328789 900 PRINTED
1634361165 909 PRINTED
1634361170 926
1634361180 930
1634361200 946
1634361205 955
1634361220 959
1634361225 960 PRINTED
1634371594 961 PRINTED
1634402669 962 PRINTED
1634402791 964 PRINTED
1634420806 966 PRINTED
1634488364 967 PRINTED
1634589724 972 PRINTED
1634605846 973 PRINTED
1634653571 974 PRINTED
1634672856 975 PRINTED
oe9ghv@radiohill-wspr:/tmp/wsprdaemon/recording.d/KIWI_2/40$

Since those epoch times are meaningless to most humans, you can run this awk command to get a more friendly output:  "awk '{ printf "%s: %4d %s\n",  strftime("%c",$1), $2, $3}'  OV_FILENAME.LOG | tail
Where you substitute for "OV_FILENAME.LOG" the name of the ov.log file you want to see.  e.g.:

oe9ghv@radiohill-wspr:~$ awk '{ printf "%s: %4d %s\n",  strftime("%c",$1), $2, $3}'  /tmp/wsprdaemon/recording.d/KIWI_2/40/ov.log | tail -n 20
Fri 15 Oct 2021 08:12:53 PM UTC:  846
Fri 15 Oct 2021 08:12:59 PM UTC:  872
Fri 15 Oct 2021 08:13:04 PM UTC:  892
Fri 15 Oct 2021 08:13:09 PM UTC:  900 PRINTED
Sat 16 Oct 2021 05:12:45 AM UTC:  909 PRINTED
Sat 16 Oct 2021 05:12:50 AM UTC:  926
Sat 16 Oct 2021 05:13:00 AM UTC:  930
Sat 16 Oct 2021 05:13:20 AM UTC:  946
Sat 16 Oct 2021 05:13:25 AM UTC:  955
Sat 16 Oct 2021 05:13:40 AM UTC:  959
Sat 16 Oct 2021 05:13:45 AM UTC:  960 PRINTED
Sat 16 Oct 2021 08:06:34 AM UTC:  961 PRINTED
Sat 16 Oct 2021 04:44:29 PM UTC:  962 PRINTED
Sat 16 Oct 2021 04:46:31 PM UTC:  964 PRINTED
Sat 16 Oct 2021 09:46:46 PM UTC:  966 PRINTED
Sun 17 Oct 2021 04:32:44 PM UTC:  967 PRINTED
Mon 18 Oct 2021 08:42:04 PM UTC:  972 PRINTED
Tue 19 Oct 2021 01:10:46 AM UTC:  973 PRINTED
Tue 19 Oct 2021 02:26:11 PM UTC:  974 PRINTED
Tue 19 Oct 2021 07:47:36 PM UTC:  975 PRINTED
oe9ghv@radiohill-wspr:~$

As you can see, the Kiwi at Holger OE9GHV does suffer from a few overloads , mostly in the early morning and evening grayline times.  
I wouldn't try to eliminate all overload events, just add enough filtering to ensure there are only a few per hour.

Of course the next challenge is to identify what bands and stations are the source of the overload events and add appropriate filters in the RF chain. 
To do that you will probably need to log on to your Kiwi during periods of many overloads and look at the 0-30 MHz spectrum.


Re: wsprdaemon.log, error message meaning

Bruce KX4AZ
 

On Mon, Oct 18, 2021 at 05:02 PM, Rob Robinett wrote:
No, those are not benign and your log file will grow unbounded.
Can you email your conf file and I'll log into it.

 
 
Emailed it to the address shown at qrz
 


Re: wsprdaemon.log, error message meaning

Rob Robinett
 

No, those are not benign and your log file will grow unbounded.
Can you email your conf file and I'll log into it.

On Mon, Oct 18, 2021 at 1:57 PM Bruce KX4AZ <bruce@...> wrote:
As far as I can determine wsprdaemon is running fine since I got it started a day or two ago.  I have noticed that the log file is full of repeated error messages of this type:

Mon Oct 18 12:30:01 UTC 2021: watchdog_daemon() starting as pid 1112
sed: -e expression #1, char 16: unknown option to `s'
sed: -e expression #1, char 14: unknown option to `s'
sed: -e expression #1, char 16: unknown option to `s'
sed: -e expression #1, char 14: unknown option to `s'
sed: -e expression #1, char 16: unknown option to `s'...

The file size is about 159 kB right now after about 9 hours uptime, just wanted to make sure these are "benign" errors that won't eventually cause a problem.
 



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


wsprdaemon.log, error message meaning

Bruce KX4AZ
 

As far as I can determine wsprdaemon is running fine since I got it started a day or two ago.  I have noticed that the log file is full of repeated error messages of this type:

Mon Oct 18 12:30:01 UTC 2021: watchdog_daemon() starting as pid 1112
sed: -e expression #1, char 16: unknown option to `s'
sed: -e expression #1, char 14: unknown option to `s'
sed: -e expression #1, char 16: unknown option to `s'
sed: -e expression #1, char 14: unknown option to `s'
sed: -e expression #1, char 16: unknown option to `s'...

The file size is about 159 kB right now after about 9 hours uptime, just wanted to make sure these are "benign" errors that won't eventually cause a problem.
 


Re: New install on Pi4 question

Rob Robinett
 

In WD 3.0 I will add checks of the receiver names to the config file validation function.
Thanks for the reports

On Fri, Oct 15, 2021 at 6:49 AM Bruce KX4AZ <bruce@...> wrote:
On Fri, Oct 15, 2021 at 08:46 AM, KD2OM wrote:
I think the problem may be the names. There is no need to use a call as the receiver name.
You are correct!  Right after my last post I went back to the original example conf file example (from the web site) and changed the receiver name to remove the '/T' suffix from the call sign, while leaving it present for the uploaded spots - important for me to distinguish different locations I use.  After a restart the spots  began uploading correctly.  I also did some more editing of the example conf file to change all of the "no" values to "yes" for the noise related reporting.  Hopefully that is working correctly too - I have a lot ore learning to do to figure out how to verify that.



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Re: Radio "limbo"

Jim Lill
 

I have 2 public systems, jimlill.com:8075 has a Nooelec filter,   jimlill.com:8073 has HB notch filters on the nearby very strong MWBC stations.  You can compare...

On 10/18/21 8:54 AM, Bruce KX4AZ wrote:
On Sun, Oct 17, 2021 at 04:03 PM, Rob Robinett wrote:
...The $16 Nooelec Flamingo AMBF (https://www.nooelec.com/store/flamingo-am.html) is enough for several of my receive sites, but you could very well need even more filtering than the 20-35 dB it provides. 
Every 10 minutes WD logs overload events to files /tmp/wsprdaemon/..../ov.log where you can learn about OVs which happen when you aren't looking at the Kiwi's S-meter.

 
Rob,
Thanks for reminding me about the Nooelec filter.  I do have the RTL-SDR filter for MW, but is a high pass filter which rolls off at 2.6 MHz, so it chops off 160m and everything below.  As expected, the (roughly) 25dB amplification (with no filtering for MW!) that I left in place yesterday created an ugly overflow mess after sunset.  I wish I hadn't rebooted the Pi before I saw your note about the overflow file in the tmp WD directory.  My dilemma with MW filtering is that this antenna has re-kindled an old interest of mine in DXing there during the daytime.  The RTL-SDR MW filter is much stronger in that band than the Nooelec. Which makes me think that the Nooelec might have just enough attenuation to prevent overloading, whilst preserving some of the MW DXing.  Until I have that filter in hand I am going to dial down the amplification by reducing the supply voltage and/or attenuation before/after the LNA.  I have the Airspy HF+ Discovery running (unamplified in parallel) off the same antenna, so comparing the WSPR spot counts between the two seems like the best way to dial in the minimum LNA strength on the KiwiSDR needed to achieve WSPR equivalency...and then see what happens at night.  I normally only visit the site during the daytime, but a night visit to make LNA adjustments would certainly be more useful.  Worst case, I can always leave the Airpsy HF in place & running unfiltered, to preserve my MW fun going forward.
Bruce


Re: Radio "limbo"

Bruce KX4AZ
 

On Sun, Oct 17, 2021 at 04:03 PM, Rob Robinett wrote:
...The $16 Nooelec Flamingo AMBF (https://www.nooelec.com/store/flamingo-am.html) is enough for several of my receive sites, but you could very well need even more filtering than the 20-35 dB it provides. 
Every 10 minutes WD logs overload events to files /tmp/wsprdaemon/..../ov.log where you can learn about OVs which happen when you aren't looking at the Kiwi's S-meter.

 
Rob,
Thanks for reminding me about the Nooelec filter.  I do have the RTL-SDR filter for MW, but is a high pass filter which rolls off at 2.6 MHz, so it chops off 160m and everything below.  As expected, the (roughly) 25dB amplification (with no filtering for MW!) that I left in place yesterday created an ugly overflow mess after sunset.  I wish I hadn't rebooted the Pi before I saw your note about the overflow file in the tmp WD directory.  My dilemma with MW filtering is that this antenna has re-kindled an old interest of mine in DXing there during the daytime.  The RTL-SDR MW filter is much stronger in that band than the Nooelec. Which makes me think that the Nooelec might have just enough attenuation to prevent overloading, whilst preserving some of the MW DXing.  Until I have that filter in hand I am going to dial down the amplification by reducing the supply voltage and/or attenuation before/after the LNA.  I have the Airspy HF+ Discovery running (unamplified in parallel) off the same antenna, so comparing the WSPR spot counts between the two seems like the best way to dial in the minimum LNA strength on the KiwiSDR needed to achieve WSPR equivalency...and then see what happens at night.  I normally only visit the site during the daytime, but a night visit to make LNA adjustments would certainly be more useful.  Worst case, I can always leave the Airpsy HF in place & running unfiltered, to preserve my MW fun going forward.
Bruce


Re: Radio "limbo"

Rob Robinett
 

With any kind of decent antenna and a reasonably quiet site, the Kiwi needs 10+ dB gain to get signals above 10 MHz to be stronger than the internal noise of the Kiwi RF amplifier.
Of course that 10 dB gain makes Kiwi ADC overloads from local AM broadcast stations even more common, so you need an AM blocking filter ahead of the LNA.
The $16 Nooelec Flamingo AMBF (https://www.nooelec.com/store/flamingo-am.html) is enough for several of my receive sites, but you could very well need even more filtering than the 20-35 dB it provides. 
Every 10 minutes WD logs overload events to files /tmp/wsprdaemon/..../ov.log where you can learn about OVs which happen when you aren't looking at the Kiwi's S-meter.

On Sun, Oct 17, 2021 at 12:02 PM Bruce KX4AZ <bruce@...> wrote:
On Sun, Oct 17, 2021 at 11:16 AM, Rolf Ekstrand wrote:
 
...see you got your Kiwi WD up and running and doing well.  What antenna(s) are you using on the RX site?     

73  Rolf
Rolf,
Currently I have one antenna for the KX4AZ/T WD site - a random wire dipole that is resonant at about 3.4 MHz, roughly 15 feet above ground level.  I am still tweaking the matching/feedline setup, using Cat 7 ethernet cable as a balanced feedline.  Earlier today I added an LNA to the KiwiSDR input which boosted the WSPR performance significantly, but I am positive that will lead to overloading later today - will need to adjust the gain.  But I am certainly having a lot of fun learning & experimenting with this new setup.
Bruce



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896


Re: Radio "limbo"

Bruce KX4AZ
 

On Sun, Oct 17, 2021 at 11:16 AM, Rolf Ekstrand wrote:
 
...see you got your Kiwi WD up and running and doing well.  What antenna(s) are you using on the RX site?     

73  Rolf
Rolf,
Currently I have one antenna for the KX4AZ/T WD site - a random wire dipole that is resonant at about 3.4 MHz, roughly 15 feet above ground level.  I am still tweaking the matching/feedline setup, using Cat 7 ethernet cable as a balanced feedline.  Earlier today I added an LNA to the KiwiSDR input which boosted the WSPR performance significantly, but I am positive that will lead to overloading later today - will need to adjust the gain.  But I am certainly having a lot of fun learning & experimenting with this new setup.
Bruce


Re: Radio "limbo"

Rolf Ekstrand
 

Bruce,

It's amazing how far you can go with almost nothing. I am usually running QRO here at 200 mW  -:)    into an old  Cushcraft R7  usually on 7 and 14 but then again there are some crafty individuals running much more.  When I started with WSPR there was even a guy in  W3 land running 1 Kw and now we have one  just south of here running 100 W.  Go figure.   

Congrats I see you got your Kiwi WD up and running and doing well.  What antenna(s) are you using on the RX site?     

73  Rolf


Re: Radio "limbo"

Bruce KX4AZ
 

Some final comments on my "radio limbo" experiment.  I've left it running since October 7th and will shut it down today (October 17th), in order to reclaim the step attenuator I've been using to adjust the output power.  Over the past week W4HOD is still the winner (5 spots), though there were two additoinal stations that spotted me twice (K4COD, WD4ELG).  All of the spots were on the 20m band.  Interestingly, I spotted myself on 40m at (new wsprdaemon setup) 'KX4AZ/T' yesterday, about 9 miles away from the transmitter.

Lastly, the measured RMS waveform voltage on 20 meters (across a 50 ohm dummy load) was 27.5 mV, putting the actual output power into the antenna line closer to 15 microwatts (-18.2 dBm), rather than the 10 microwatts (-20 dBm) that I previously estimated...though with line/transformer losses for the EFHW antenna perhaps the actual radiated energy was not very far from 10 microwatts.


Re: Wsprdaemon location error (mine) & noise reporting

Bruce KX4AZ
 

Gwyn,
Thank you for the quick feedback, happy to know the noise data is being uploaded & with the correct location.  Doesn't matter to me whether it is -T or /T, either way it helps me distinguish the location from my other ones.  And yes, I have a LOT of studying to do with all of the information available at the wsprdaemon web site.
73,
Bruce KX4AZ


Re: Wsprdaemon location error (mine) & noise reporting

Gwyn Griffiths
 

Hello Bruce
Your noise data are being reported to the database. There's lots of documentation on wsprdaemon.org on how to query the database, but a quick query brings up the following as a few recent lines on 40 m:

tutorial=# select * from wsprdaemon_noise_s where site like 'KX4AZ%' and band='40' order by time desc limit 15;

        time         |  site   | receiver | rx_grid | band | rms_level | c2_level | ov |  seqnum  

---------------------+---------+----------+---------+------+-----------+----------+----+----------

 2021-10-16 14:56:00 | KX4AZ/T | KX4AZ_1  | EN74gc  | 40   |   -132.02 |  -143.22 |  0 | 25616876

 2021-10-16 14:54:00 | KX4AZ/T | KX4AZ_1  | EN74gc  | 40   |   -134.97 |  -142.96 |  0 | 25616570

 2021-10-16 14:52:00 | KX4AZ/T | KX4AZ_1  | EN74gc  | 40   |   -129.19 |  -142.62 |  0 | 25615900

 2021-10-16 14:50:00 | KX4AZ/T | KX4AZ_1  | EN74gc  | 40   |   -127.36 |  -144.05 |  0 | 25615125

You will see that the site name, as set in your wsprdaemon.conf for the upload id, is still as /T and not -T in this listing.
However, it is as -T in the webpage with your noise graphs at http://wsprdaemon.org/graphs/KX4AZ/

Any rigorous calibration of antenna system and local noise is so fraught with problems and pitfalls, there is no real need to be concerned about "polluting" the noise database. If someone is really serious about using your noise data I am sure they would get in touch to learn more about your setup etc.

best wishes
Gwyn G3ZIL

 


Wsprdaemon location error (mine) & noise reporting

Bruce KX4AZ
 

After a bit of a struggle with naming conventions for my remote receiver site 'KX4AZ/T' at EN74gc, I was able to get wsprdaemon going yesterday on the Pi4, so that spots are now being reported from my new KiwiSDR. A huge thank you to Rob for creating/maintaining this software!

Alas, I just discovered that I entered the wrong location (EN73hx versus true location of EN74gc) into the conf file for wsprdaemon.  It's only about a 9 mile location error - and is the location where I am currently running a 'KX4AZ' transmitter at about 10 microwatts RF output (a separate "story").  I have just corrected the location error and rebooted the Pi.

It bothers me a bit that I have "polluted" the WSPR database with a location error like that, but at least it is not a gross location error, as in another US state(!).  But I also enabled noise reporting yesterday, first using 'KX4AZ/T', eventually changing it to 'KX4AZ-T' after realizing that the '/' character might be problematic, as it was for the receiver name.  Before I go any further, I wanted to ask if the noise data are being reported properly to the database (albeit with the location error that I have just fixed).  And secondarily, since I have not yet done any calibration for the antenna setup, I want to make sure I am not "polluting" the noise database by enabling this feature while I am still studying/learning about it.  I am happy to shut it off if that would be beneficial.


Re: HB9VQQ testing Kiwi SDR

Glenn Elmore
 

Rolf
Using "Quiet receiving site", curve C and "galactic noise" curve D from ITU-R P.372.8 as a guideline, one can probably stand a system noise more than 20 dB above KTB before it impacts SNR  from a losslessly matched antenna. This presumes that not only receiver side noise and NF but also IMD, ADC non-linearity and common-mode and similar QRM ingress is no higher.  It also recognizes that ground losses and ground noise currents can be a significant part of the feedpoint impedance and noise floor even  up at 10 MHz and particularly for horizontally polarized antennas.

If the SNR present on the antenna being used is substantially due to far-field sources, propagated signal and propagated noise, then except for IMD and ADC issues the receiver used shouldn't impact things much. In real environments of course that's the rub.  Both near-field sources and strong signal overload from out-of-band signals can make this not the case.

It does say that for a well matched antenna (well matched to radiation resistance, not necessarily the presented feedpoint resistance),  NF of the preamp and rx probably don't matter much. When one starts using poorly matched antennas, particularly a problem for electrically small antennas, then the requirements on the rx system hardware and ingress mitigation get greater.

If you are seeing appreciable difference between receivers/detectors then I suspect you have a problem with ingress,ADC/IMD and that these need to be eliminated.

Just my opinion from HF active antenna, preamp and receiver investigations...

Glenn n6gn


Re: HB9VQQ testing Kiwi SDR

KD2OM
 

Rolf,
I am using three different amplifiers built by N4CY Everett Sharp. They all are 11 dB gain. He has changed the version several times, one has a relay to disconnect the antenna when no power is supplied. I am feeding power to them using a bias T, also built by Everett. 
I do need to increase the gain for my beverage antenna, candidates are a 20 dB gain amplifier from Advanced Receiver Research and a 23 dB amplifier designed by K8ZOA from DX Engineering.

73,
Steve KD2OM 

On Oct 15, 2021, at 13:44, Rolf Ekstrand <rekstrand@...> wrote:

Hi again y'all

I have run my Kiwi  here with AM filter for more than a year now almost 24/7 and I am very happy with it.  I am only using an old ground mounted  Cushcraft R7.  I am still planning to expand with additional kiwis  for the low bands and a vertical log periodic towards middle EU.  In the meantime I like to try a LNA ( with a 50 ohm HP on let say 10 Mhz) on the vertical.     

I guess I could cobble together a Norton amp or similar and the HP filter, but before doing so,  what are the "big gun" WD kiwi stations out there using if they need a boost??

73  Rolf


Re: HB9VQQ testing Kiwi SDR

WA2TP - Tom
 

Not sure I’d consider myself a big gun, but I have had very good results with high spot counts. 

I am not using any and pre-amplification on the resonant antennas. 

The only antenna with a pre-amp here, is the wellbrook active loop. 

I have been plagued with CM paths and local noise sources, which is what I focused on.

I built my own filters for the AM BB problem stations. 

Tom
WA2TP 

On Oct 15, 2021, at 7:44 AM, Rolf Ekstrand <rekstrand@...> wrote:

Hi again y'all

I have run my Kiwi  here with AM filter for more than a year now almost 24/7 and I am very happy with it.  I am only using an old ground mounted  Cushcraft R7.  I am still planning to expand with additional kiwis  for the low bands and a vertical log periodic towards middle EU.  In the meantime I like to try a LNA ( with a 50 ohm HP on let say 10 Mhz) on the vertical.     

I guess I could cobble together a Norton amp or similar and the HP filter, but before doing so,  what are the "big gun" WD kiwi stations out there using if they need a boost??

73  Rolf


Re: HB9VQQ testing Kiwi SDR

Rolf Ekstrand
 

Hi again y'all

I have run my Kiwi  here with AM filter for more than a year now almost 24/7 and I am very happy with it.  I am only using an old ground mounted  Cushcraft R7.  I am still planning to expand with additional kiwis  for the low bands and a vertical log periodic towards middle EU.  In the meantime I like to try a LNA ( with a 50 ohm HP on let say 10 Mhz) on the vertical.     

I guess I could cobble together a Norton amp or similar and the HP filter, but before doing so,  what are the "big gun" WD kiwi stations out there using if they need a boost??

73  Rolf

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