Ham radio stuff

1. Weather balloons and 405MHz QFH antenna

Tried to receive a weather balloon. For more information about weather balloons, software and antennas see here.
I use a homemade QFH antenna for 15 Euro.

westher balloon antenna

westher balloon antenna

As hardware receiver I use a TTGO-Esp32-LoRa-433 MHz module. All informations and MySondyGo software can be downloaded here.


MySondyGo MySondyGo

2. Low noise amplifier

LNA (LNA4ALL) from 10 MHz - 2 GHz with a noise figure down to 0.6 dB at 144 MHz and gain up to 24 dB. It perfectly works in combination with a SDR (funcube dongle).
Low noise amplifier LNA4ALL

3. T-bias

T-bias is used e.g. between antenna preamplifier and receiver to provide power supply via coax cable for a preamplifier.
This design (PCB) is made by F1OPA.
Insertion loss: <1 dB (10 -1800 MHz)

Tbias T-bias

This T-bias has SMA connectors and uses PCB and metal box by RF Basic Store. Circuit see here by Adam 9A4QV.
Insertion loss: <0.6 dB (10 - 2000 MHz)

Tbias T-bias

4. Probe head for noise detection

With this probe head it is easy to measure common mode and differential mode noise (e.g. power supply).
BNC connector, 50 Ohm resistor and ferrite choke.

probes for noise

5. LNB (low noise block) modifications I

- to test my RF test equipment
- to understand microwave circuits
- to change it for 10.4 GHz usage instead of 10.7-12.7 GHz
- to do the impossible and have fun with 5? parts

Octagon PLL LNB
Original Octagon (OSLO) LNB by OE7DBH

Darko OE7DBH made some modifications for amateur TV and has a lot of stuff for sale.
- SMA output connector or F output connector
- SMA input connector (horizontal and vertical)
- additional input coupling capacitor
- 26 MHz quartz instead of 27 MHz
- mounted on copper plate


Gain and noise figure with CANFI v2.6 and EATON 2075:
- noise figure is around 0.6 dB at 11.5 GHz
- noise figure is around 2 dB at 10.5 GHz and up to 3 dB at 10.368 GHz



Input Return loss measurement between 8.5 and 13.5 GHz

LNB return loss

Until now it wasn't possible to trim the LNB for best noise figure at 10.4 GHz. I tried to play with stub positions and stub length.

6. Downconverter for 10GHz

I ordered a 10GHz downconverter PCB made by Kuhne Electronic and all necessary parts from Eisch-Kafka-Electronic.
NF = 1.2 dB
Gain = 22 dB (after some filter improvements with stubs)
LO = 9936 MHz

10 GHz down converter

10 GHz down converter

10 GHz down converter

10 GHz down converter

7. Sensitive RF detector

PCB is made by W1GHZ and RF detector uses power detector IC AD8307. In my case there is a 50 Ohm matched 10.7 MHZ ceramic filter in front of the detector.
With a gain factor of 1.47 it gives around 0-3300mV for a dynamic range of 90dB.
Bottom side shows input filter matching.

RF power detector RF power detector

8. LNB (low noise block) modifications II

Again some modifications and tests. I used a twin Octogon LNB with PLL. Click image for full resolution.

twin PLL LNB I cutted the track after the second IF input/output (upper right corner) and I connected this input/output via a 1nF capacitor to the 25 MHz quartz.
Now it was possible to inject a very stable external 25 MHz via the second IF port. I use the first IF port a standard signal port plus power supply.

twin PLL LNB

9. Amplifier for 10 GHz

For this design made by RF-Basic-Store I use a MMIC MGA-86576. Its usage is specified up to 8 GHz but it works up to 10 GHz with a gain of 11 dB.

10 GHz amplifier

10 GHz amplifier

10. Modified NORT PLL for 12 GHz

This NORT module has a connector for 12 V power supply (~260 mA power consumtion), lock signal and SPI connection. Inside there is an ADF4153 fractional frequency synthesizer and I use an Arduino Mini Pro 3.3V to program the ADF4153 after power up. Output power is approx. 13 dBm at 11952 MHz.

NORT module

NORT module

NORT module


This module has a bandwidth of approx. 500 MHz and it is possible to adjust center frequency between 11.25 and 13.25 GHz. Under the soldering point there is a short-circuit flag (see red marked short-end stub).
Move this short-circuit flag to change frequency range. Shorter stub -> higher frequency (e.g. 12 GHz), longer stub -> lower frequency.

I made an external Ref-input and removed inside VCTCXO.

NORT module

NORT module modification

Built in PLL controller board made by OE8WOZ

Now I use a tiny controller board inside of the NORT module instead of an external arduino board. It is possible to send all ADF registers to the PLL and store these registers.

ADF4153 controller
NORT module ADF4153 controller

Example for my 24 GHz Transverter:

NORT module ADF4153 controller

Software made by OE8WOZ:

NORT module ADF4153 controller

11. Morserino32

I like is Arduino based morse trainer, receiver, transmitter, ....
For more information have a look here.


12. Horn antenna with SMA transition for 10 GHz

WR90 (=WG16) transition for 8.2-12.4 GHz with inner dimensions 22.86 x 10.16 mm. I found the horn on eBay.

10 GHz horn

13. Simple horn antenna for 47 GHz

I made this horn antenna with a step cone drill and cone angle is around 40. Horn dimensions are calculated with PCAAD.exe

47 GHz horn

14. GPS stabilised 10MHz frequency reference

Sometimes I need a very stable 10 MHz frequency reference for my test lab equipment. James Miller G3RUH has designed such a system.
Output is a 4.8V TTL (pk-pk, Low 0/ High 4.8V) square wave (50 Ohm output). It can drive a 50 Ohm load with amplitude 2.4V pk-pk (14 dBm).

Isotemp OCXO134-10 with 10 MHz output

TU60-D120 GPS module with 10 kHz output


15. 10 MHz filter for 10MHz frequency reference

Most 10MHz references have a square wave. With this filter by W1GHZ we get a clean 10MHz sine wave signal.

10 MHz filter

16. Passive mixer up to 15 GHz

microwave mixer

17. Multiplier up to 18 GHz

BAT15 used between ground and signal pin and a return path between pin and ground.

microwave multiplier

18. 10 GHz wave guide band pass filter

I built my own 2-cavity band-pass filter for 10.4 GHz by Zack Lau (W1VT).
Insertion loss is 1.5 dB, band width is 25 MHz@3dB.

10 GHz band pass filter

10 GHz band pass filter 10 GHz band pass filter 10 GHz band pass filter

19. Alcatel detector/mixer/multiplier for 24 and 37 GHz

It is possible to use these modules as mixer (both ports), detector (only one port) or multiplier (both ports). That's perfect to detect microwave and to generate microwave.

24 GHz device:

microwave alcatel mixer

38 GHz device:
I use this device for 47 and 76 GHz.

microwave alcatel mixer

microwave alcatel multiplier

microwave alcatel detector

20. GPS disciplined reference oscillator

Here I use a nice unit by Leo Bodnar. It has 2 separate outputs (3.3V CMOS level) from 450 Hz to 800 MHz and it uses GPS reveiver for very stable output frequency. Output power is up +13 dBm.
Current consumption @ 12V DC: 190 mA

GPS reference Bodnar

As the output signal is a square wave it is useful to use a low pass filter to make the output signal sinusoidal. Then it is possible to connect the GPSDO output directly to a transverter to generate the LO. I use the PCBs from RFzero.

21. Modified FT-817ND

FT-817ND modification

I made 4 modifications:

  • TCXO-9 instead of factory oscillator. It is a 22.625 MHz oscillator with 0.5 ppm.

  • 68.33 MHz IF output to build a panadapter with a SDR

    I mounted a "panoramic adapter tap board" from SDR-Kits into the FT-817ND. At the rear side there is an adittional SMA outout providing IF signal.

    FT-817ND modification

  • Power supply with Powerpole

    FT-817ND modification

  • Supply +5 V to the I.F. cable for Tx switch

    FT-817ND modification

    FT-817ND modification

22. Rx-attenuator 0-70 dB between transverter and I.F. transceiver/receiver

At short distances Rx signal is too high. An attenuator could be used but then it is not possible to transmit. This attenuator is useable for Rx and Tx.

RX Tx attenuator

23. New important circuits for microwave transverters

Designed by Hans, OE2JOM.

  • Power supply circuit board for microwave tripler module

    microwave power supply
  • Tx and Rx biasing circuit board for microwave mixer diode

    microwave power supply
  • IF amplifier circuit board

    microwave if interface

24. Lathe and boring/milling machines

This one is more mechanics than electronics but without some important machines it is not possible to make microwave parts.
It is a Holzmann Machines ED300FD_230V lathe.

OE2IGL lathe

Now I have this drill/milling machine. It is a Paulimot Sieg SX2L boring/milling machine.

OE2IGL milling

25. 5-6000 MHz broadband amplifier

I made some measurements of this broadband amplifier and it works fine. It uses a SBB5089Z amplifier chip

Power supply: +5 V
Power consumption: 70 mA
Frequency range (official): 50-6000 MHz
Gain: 15-20 dB
Noise figure: 4 dB
Output P1dB: 15-20 dBm

broadband amplifier

26. CW keyer and CW decoder via mobile phone and your RIG

Because of no need I never learned morse code. But sometimes it would be great to make some easy CW QSOs with my microwave and EME equipment. Therfore I looked for an user friendly solution (easy and less time consuming text typing without an computer) in combination with a mobile phone.
I found "morse expert" and "web CW keyer". Each app needs a small signal interface between phone and RIG.

Web-cw-keyer needs full sound level from mobile phone. Use Schottky diodes with low forward voltage (<400 mV).

27. Weather Box for microwave link predictions

Originally designed by Barry Chambers G8AGN but I made some code changes. Using a temp, humidity, pressure sensor this device can predict S/N of any microwave link (including atmospheric loss).