Various projects throughout the years.
144 MHz transverter
High performance 144/14 MHz transverter. This transverter is a version based on the famous Javornik 144/14 transverter from S53WW. Various components from the original design are obsolete so the design was changed and a new PCB was designed.
144 MHz amplifier with 2x4CX250b’s W1SL design “Plumbers Special”
This amflifier with 2 4CX250b tubes was build around 1976 and delivered 1 kW CW in class a. It was used in many contests and for my first CW EME contacts.
4 x 7H/7V 144 MHz LFA Yagi’s
Portable setup with a stack of 4 XPOL Yagi’s with 7 horizontal and 7 vertical elements.
High power transfer relays”Dirty and Ugly” for 144 MHz
YU1CF style transfer relays for 144 MHz to be able to transmit and receive horizontal, vertical or circular on 144 MHz. These relays are “Dirty and Uggy”and are using 7/16 connectors for highpower and N for receiving. They can handle 2.5 kW easily.
14 elements 144 MHz LFA Yagi with 3 reflectors
14 elements 144 MHz LFA Yagi PLUS 2 Yagi. 16.63 dBi Gain, 36.35 dB F/B. Ultimate Yagi for 144 MHz DX and enough gain to work EME. Full azimuth and elevation.
70 MHz transverter OZ2M
When 70 MHz could be used in the Netherlands there were no transceivers available for 70 MHz. My FT-847 could do 70 MHz after a modification but a seperate 70 MHz transverter was a better option.
144 MHz 2.5 kW amplifier using 2 LDMOS MRF6VP61K25H
2.5 kW 144 MHz amplifier using 2 LDMOS devices from NXP. Gain of the amplifier is 26 dB on 144 MHz so 5 Watt input will drive the amplifier to it’s maximum output. Powerspike protection is critical.
Javornik 144/14 transverter
The original 144/14 MHz transverter from S53WW (S51RM/S53RM). As published in 2002 and still considered as state of the art in performance on 144 MHz.
Pulsegenerator for LinRad
Adaptive polarisation is key in EME when using XPOL antennas. In my EME-system this is achieved by using the 2 receiving ports from the Javornik 144/14 transverter and feed them via an AfrediSDR to LinRad from SM5BSZ. The smart noiseblanker in LinRad needs to be calibrated before you can use it. This does the trick. Then I/Q goes to WSJT-X.
OE5JFL antenna controller
0.5 degree resolution freestanding azimuth and elevation controller designed by OE5JFL. Combined with a GPS this device can track the moon and other sources with high resolution.
144 MHz Phase Shifter / Noise Canceller
Birdies or other noise can be interfering with the signal you want to receive. The cause is local so when you receive the birdie or noise on a seperate antenna, you can feed it with 180 phaseshift to your receiver and you will be able to filter the noise out. Works great on birdies but does not cure solarpanel noise.
SAM4 Aurora monitor
Working DX via aurora is great… to be able to monitor the magnetic field a 3-axis magnetometer was build.
Sequencer and polarisation switch
When using high power and low noise preamplifiers, sequencing of relays is necessary. This does it all and also controls the polarisation of the TX-chain (receiving is adaptive) and the TX-inhibit of my tranceivers and transverters.
5-stage sequencer
5 stage sequencer for sequencing the relays when using high power and preamplifiers. Simple and straight forward to use when portable or as a spare.
Tom… at the PA4EME station
Meet Tom… Tom is translating keyboard to speech… I could run a SSB contest without loosing my voice. The transceiver you see is my R2CW contest tranceiver from the Tsech Republic. It’s rare and wanted.
Winkeyer
WinKeyer is great when you are in a CW contest eg the Memorial Marconi CW contest. I build it to use it with the VUSC4WIN contest software van Lada, OK1DIX.
My first electronic keyer
Simple keyer using 4011 and 4027 IC’s. It was my first electronic keyer and still in use as, after many years of use as an external keyer, I placed into my R2CW contest tranceiver. Almost 50 years old and still doing well.
Lightning detector
This lightning detector is located in my antennatower and warns me for nearby thunders that can damage my preamplifiers. It’s station 1152 of the wellknown Blitzortung website.
ERC-M Rotor controller
This controller was build to use F1EHM Moonsoftware and Yaesu GS-550 rotor on portable EME.
Adaptive RX
Phaseshifter PCB for LinRad and WSE receivers.
Triode Controller
Bias and controller for GS35b 144 MHz triode amplifiers
Absolute encoder
Just for fun… absolute BCD 360 degree encoder…how graycode works.
Versatower BP60sx
In 2006 a Versatower BP60 was installed. Some pictures of the build including the strenghth and stiffness calculations for the tower.
144 MHz 7 el LFA for portable use
Noiselevels are increasing in the city due to solarpanels. A portable stations was build to escape the noise and to enjoy the weather.
TNC-2 modem
A TNC-2 modem was build to couple WinLink to tranceivers for DARES (Dutch Amateur Radio Emergency Service).
F1CXO cavity for 144 MHz GS35b amplifier
One of my GS35b amplifiers for 144 MHz.
3 kW 144 MHz amplifier DL4MAE design
This amplifier has been in the PA4EME shack for many years. When the Sovjet Union collapsed, many Russian tubes came on the market including the rugged GS35b. 4200 Volt at 1,2 A Anode current delivered 3 kW at 160 Watt input.
VHF-UHF colums in CQ-PA magazine
For many years I have written the VHF-UHF colums for CQ-PA magazine. For a long time the magazine was protected by copyright but nowadays all numbers are in the archive of the VRZA. All my colums can be found as PDF on the website.
MMMonVHF website
Maybe the biggest project off all…. the MMMonVHF website. Since 2005 I’m a member of the MMMonVHF (Make More Miles on VHF) and editor for the sections Tropo and Sporadic E. The webpage was originally programmed in PHP by Ansgar, DG2KBC. Since May 2024 I took over and keeping the PHP-code alive is a real challenge as I’m not a professional programmer and learning “on the job”.
Power dividers / combiners
Stacked Yagi’s, transmitting horizontal and vertical need combiners. These can handle 5 kW easely.