PE4KH Amateur radio - Koos van den Hout

PE4KH license plate

Most recent QSO's for PE4KH

Callsign Band Mode Locator RST(R) RST(S) Satellite

I passed my novice radio amateur exam in March 2013 and I registered the callsign PD4KH (pappa delta four kilo hotel!). I passed my full radio amateur exam in March 2016 and I registered the callsign PE4KH (pappa echo four kilo hotel!). In April 2022 I added CW included.
PE4KH on PE4KH on twitter

I am usually located around maidenhead locator: JO22NC

QSL policy for PE4KH

I upload logs to and ARRL Logbook of the World, during and after being active on the radio. I upload logs to and clublog on a regular basis. I like paper cards via the QSL bureau so I send those out when requested or when I think the other party will appreciate one and I will respond when I receive a card. You can also request a card via the Log Search on clublog for PE4KH using the OQRS service. Notifying me via e-mail that you would like a card is also possible.

I appreciate SWL reports for QSOs and will respond.

gallery of eQSL cards received by PD4KH, PE4KH, PE4KH/P, DL/PE4KH.


Antenna rotor project
Amateur Satellites
D-Star digitale amateur radio (Nederlands)


Recent contact (QSO) map for PE4KH built with leafletjs and openstreetmap
gcmwin for linux maps with gridsquares contacted (red) and confirmed (blue) :
Mapped HF contacts by PE4KH
Mapped 10M contacts by PE4KH
Mapped 15M contacts by PE4KH
Mapped 17M contacts by PE4KH
Mapped 20M contacts by PE4KH
Mapped 30M contacts by PE4KH
Mapped 40M contacts by PE4KH
Mapped 60M contacts by PE4KH
Mapped 80M contacts by PE4KH
Mapped 2M contacts by PE4KH
Mapped 70CM contacts by PE4KH
Mapped satellite contacts by PE4KH

The 'hamradio' items from my homepage

2023-09-20 Adding an RSS feed to my amateur radio site
A remark on triggered me: Quick reminder that there is a public RSS aggegator that combines all the ham radio blog feeds into one web site
Quick reminder that there is a public RSS aggegator that combines all the ham radio blog feeds into one web site:
And I wanted to add the latest from my site PE4KH Amateur Radio but there was no RSS feed available.

I've been wanting to add such a feed for a while but didn't get around to it. This was the trigger I needed. The perl script that generates the feed for has now been updated to allow for 'filtered' feeds for and other sites that have a specific part of the main feed.

And I moved the script to version control so I can work on it on the development server and deploy to production when it's working fine.

Update: you can now find my posts over there

The feed is now accepted and imported on PE4KH amateur radio -

2023-09-17 I participated in the Scandinavian Activity Contest
CW contest filling the bands on a websdr This weekend was the morse edition of the Scandinavian Activity Contest and I decided to participate, mainly to get some more morse contesting experience.

I made 74 contacts, even some on the 10 meter band which cooperated Saturday afternoon.

Band      QSO   Points   Multipliers
80m          0       0       0
40m         13      13       9
20m         55      55      22
15m          0       0       0
10m          6       6       5
Total       74      74      36

Dupes:     0
Invalid:   0
QSO Total: 74
Score:     2.664 (Diff: 2.664)
BAND:      ALL

2023-09-13 I bought an RTL-SDR blog v4 dongle, and it's not working in Linux .. yet
A few weeks ago I saw 'buzz' all around about the RTL-SDR v4 dongle coming out: RTL-SDR Blog V4 Dongle Initial Release! and lots of people reporting clicking "buy now". I did the same, without even having a good reason to buy one. It is the third RTL-SDR dongle in the house, but the first one from RTL-SDR.COM. RTL-SDR dongles allow for the reception of radio signals in a wide range of frequencies where the processing of the signals is all done in the computer.

I ordered it through AliExpress but making sure I got the right version via RTLSDRBlog Store on AliExpress.

It arrived earlier and I can't get it to work with the Linux SDR software stack I use, even on the newest laptop, which uses:
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name             Version        Architecture Description
ii  gqrx-sdr         2.15.8-1build1 amd64        Software defined radio receiver
ii  gr-osmosdr       0.2.3-5build2  amd64        Gnuradio blocks from the OsmoSDR project
ii  librtlsdr0:amd64 0.6.0-4        amd64        Software defined radio receiver for Realtek RTL2832U (library)
The dongle is recognized, but there is just noise, no signal to decode, even when I try strong broadcast stations. The previous RTL-SDR dongle receives the same stations fine, so it's an amplification or tuning problem.

Checking the web finds librtlsdr/librtlsdr: Software to turn the RTL2832U into an SDR - GitHub which has a recent commit: add rtl-sdr blog v4 support · librtlsdr/librtlsdr@fe22586 · GitHub which sounds exactly like what I would need. So it's not working.. yet.

2023-09-08 New electronics and amateur radio project: mains power filter
One of my ever nagging issues with amateur radio at home is the amount of interference I get, which makes receiving weak amateur radio signals very hard or even impossible.

The mains power cables coming into the house seem to be one of the main sources, which would explain why the source of the interference is hard to pinpoint: it's everywhere around the mains power wires in the walls and ceilings.

I found Clean Up Your Shack – 2019 which has plans for a mains filter that should improve matters.

I ordered parts from Mouser. The exact parts weren't always available, so I had to do some searching for comparable parts. Including a somewhat bigger case and different cable glands. All the ferrite was available from Mouser exactly as wanted.

The order got delivered quickly. The next step was to find time to actually work on this project!

Recently I found time to sort out what I have and what I still miss to build it all. The ferrites ordered are so big and heavy they come in protective packaging to keep them from cracking due to bumps or the package handling!

I also did a 'test fit' putting all the parts in the case I bought. I thought it might be a bit big until I fitted all the ferrite in: the ferrite is very big, so the case I bought isn't really oversized!

I found out I'm not perfectly done yet. I could use a step drill to get the holes in the case perfectly round and I found out the cable glands I bought did not come with the matching nuts. Time for some more on-line orders!


Parts ordered: mains power strip, the matching nuts for the cable glands and spade connectors. I checked which size step drill I would need and it turned out the hole for the cable gland is 15 millimeter and it would be easier to use a 16 millimeter drill.

2023-09-06 New entity in amateur radio: Greenland
In interesting DX news I saw OX3LX Greenland - DX-World which is a new entity for me. I got OX3LX in the log on FT8 on 28 August.

I also set an alert for Greenland in morse which helped me get OX3XR in the log on 6 September.

Both contacts were confirmed pretty fast, I am now at 164 entities confirmed in total (any mode) and at 95 entities in morse.

2023-09-03 Two more countries in morse confirmed
The search to get more countries confirmed in morse is continuing. At the end of July a team was active under the call 1A0C activating the entity Sovereign Militairy Order of Malta which is a catholic order with a lot of history. There is no territory for this entity, but internationally it is seen as a sovereign entity and radio amateurs like having yet another entity.

I got in the log with 1A0C and after donating to the good work of the Order of Malta Italian Relief Corps I got confirmation for these contacts.

Another new country in morse was Luxemburg where LX90RTL is active celebrating 90 years of broadcasting in Luxemburg with Radio Luxembourg. This contact is now also confirmed, and I am at 94 countries confirmed in morse code. The magic 100 for DXCC CW is getting closer.

2023-08-28 Hacking shopping carts with RF signals
My favourite mix of subjects: security (or lack of security) and RF signals.

Joseph Gabay has researched how shopping carts with wheel locks are locked and unlocked, and found out it's really easy to replay these signals. The signals for the shopping carts with wheel locks from Gatekeeper systems are at 7.9 kHz (ELF or extremely low frequency) and at 2.4 GHz (UHF or Ultra High Frequency and the license free range also used by WiFi and Bluetooth).

After a lot of work with a coil to act as a (bad) antenna for 7.9 kHz he found out the magnetic field of a speaker in a smartphone can also create the field and do replay attacks via audio files.

All of this at Control Shopping Cart Wheels With Your Phone! including the video of the Defon 29 presentation about this.

Now I really wonder how the shopping carts at our nearby supermarket work! I know it is a wire loop in the parking lot, I've seen the loop transmitter in the supermarket.

Found via Issac Kelly: "Somebody linked this to me rec…" - Mastodon


The nearby supermarket uses the Rocateq system which operates on 8.13 kHz. So I can probably do the same replay attacks to these carts. Found by taking a picture of the loop transmitter in the supermarket and checking for the name in some variations at the searchable FCC ID Database and finding COP Caster STD&OCS; COP User Manual Zhuhai Rocateq Technology which lists the VLF frequency: 8.13 kHz.

2023-08-18 Another country confirmed
In the preparation for the CQ WPX CW contest I had a contact with an amateur radio station in Antigua and Barbuda preparing for the contest: V26BP Bill (US callsign W5SJ) operating from Antigua and Barbuda for the contest.

Antigua and Barbuda is a sovereign country in the West Indies.

The QRZ page promised uploads to Logbook of The World (LoTW) so I asked very nicely after a few months for confirmation and got a quick response that the logs would come soon. A week later the confirmation indeed came in.

I'm now at 92 countries confirmed in morse, 100 is getting close...

2023-08-14 Ik heb gereageerd op de internetconsultatie "Pakketwijziging 2023-1 Nationaal Frequentieplan 2014"
Recent kwam er berichtgeving vanuit de Veron: Raken radioamateurs 430-440 MHz definitief kwijt? Maak bezwaar! - Veron

Na het doorlezen van wat echt het voorstel was vond ik de titel overdreven. We raken de band nu niet kwijt.

Wat wel kan gebeuren is dat de interferentie toeneemt, en dat wil ik als radioamateur ook voorkomen. Ik heb dus ook mijn zienswijze opgeschreven en diverse keren bewerkt om onder de grens van 2500 karakters te blijven. Ik wilde expres niet met een aangehangen document werken om zo mijn zienswijze direct leesbaar te hebben staan.

Tijdens het proces van bewerken heb ik natuurlijk een lokale kopie bijgehouden waar ik ook blij mee was toen de site een keer haperde. Uiteindelijk is het geworden:
Volgens mij zullen de wijzigingen in het Nationaal Frequentieplan voor de frequentiebereiken van 430 tot 436 MHz tot ongewenste situaties leiden.

Binnen het gebied van 430 tot 436 MHz zitten ook frequenties waar binnen de amateurdienst zeer zwakke signalen mogelijk zijn die de primaire gebruikers (radioamateurs) zonder interferentie willen ontvangen. Dit valt uiteen in twee delen, te weten het deel voor zwakke signalen tussen radioamateur stations onderling, op 432 tot 433 MHz en het deel voor signalen van satellieten die ook actief zijn in de amateurbanden, te weten 435 tot 436 MHz.

Mijn verwachting is dat dit slecht samengaat met de nieuw voorgestelde toepassing.

In theorie zou de tertiaire status van de nieuwe gebruiker van dit frequentiegebied betekenen dat deze gebruiker interferentie accepteert van de primaire gebruiker en geen interferentie veroorzaakt of direct stopt als de primaire gebruiker interferentie ervaart. In de praktijk verwacht ik dat dit in het dagelijks gebruik tot conflicten zal leiden. Volgens het document waar deze wijziging op gebaseerd is, EU Document Decision (EU) 2022/180 gaat dit om 'Medical data acquisition devices'. Het publiek zal niet kunnen begrijpen dat een radioamateur die haar of zijn hobby aan het uitoefenen is voorrang zou moeten krijgen op communicatie van een medisch apparaat en dat de radioamateur zou kunnen vragen om dat medische apparaat uit te schakelen.

Ik verwacht conflicten die vergelijkbaar zijn of erger dan met wat er nu al optreed rond 433.9 MHz. Neem bijvoorbeeld dat het algemeen publiek niet snapt dat een zendamateur die bezig is met haar of zijn hobby voorrang heeft op het kunnen openen en sluiten van auto's, terwijl dat bij een pure uitleg van het nationaal frequentieplan wel de status zou moeten zijn. Naast het tekort aan begrip wat kan leiden tot conflictsituaties is er ook de extra emotionele kant dat het om een medisch apparaat gaat, wat ongeacht de kwaliteit van het apparaat ook vrij zwaar zal wegen voor het algemeen publiek als argument dat het voorrang zou moeten hebben.

Naast de eerder genoemde mogelijke conflictsituaties is er ook nog de kans op de omgekeerde situatie als radioamateurs bezig zijn met vermogens richting het maximum voor dit frequentiegebied en dan storing veroorzaken in de medische apparatuur. Ondanks de tertiaire status van de medische apparatuur zie ik ook hier oorzaken van conflicten omdat daar ook dezelfde emotie telt van medische apparatuur versus hobbygebruik.

Verwijzingen en geraadpleegde bronnen:

2023-08-09 Asking nicely for LoTW confirmations, and getting Northern-Ireland confirmed
As I am working towards getting 100 countries confirmed in morse I do keep an overview of countries I have at least one contact with which isn't confirmed yet on Logbook of The World (LoTW). On LoTW a contact is only confirmed when both sides upload a signed log with the same contact.

Yes, LoTW uses X509 certificates and signing, they just hide it mostly from the user.

So when I have a country in the log where I'd like to get digital confirmation I follow a few steps:

I first check the page for the callsign on Most radio amateurs maintain a presence on that site and may mention their policy for confirming contacts. Especially for rare entities where other radio amateurs will be interested in getting those entities confirmed.

If that page doesn't answer this question the next step is to check the call (or calls) with the 'find call' option in LoTW. Here it is possible to see what the last time is a log was uploaded and processed for that call. Or it shows that the call isn't active on LoTW at all. In that case I stop searching. Using LoTW is somewhat complicated and I don't feel the need to convince someone to start using it.

If the amateur is active on LoTW I try to guess whether regular uploads can be expected. Some have not uploaded anything in years, others seem to upload once a year in the month of January. Or the amateur uploads somewhat irregularly.

Now I am nearing 100 countries confirmed in morse I do sometimes write an e-mail to the amateur asking to confirm the contact if I haven't seen confirmation after a few months. With all the details needed to find the contact in the log so they only have to do minimal work to look up the contact.

Getting Nothern-Ireland confirmed

In amateur radio Northern-Ireland is a separate entity and I had a few morse contacts with stations in Northern-Ireland in the log but none confirmed, not even after 3 months. So I mailed two of them which are regularly active on LoTW. The first one responded after a few days with a screenshot of the confirmed contact.

So now I have 91 countries confirmed in morse on LoTW. The certificate for 100 countries in morse is getting closer!

Items before 2023-08-09
This page is created by Koos van den Hout, reachable via e-mail as my callsign @ Find me on Mastodon as
Other webprojects: Weatherstation Utrecht Overvecht, Camp Wireless, wireless Internet access at campsites The Virtual Bookcase book reviews
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