Under this headline I have collected both engineering aids and descriptions of nice circuits to build yourself.

Helpful engineering tools

RF-resistance and skin depth of a circular conductor (25 kB). Calculate the RF-resistance and skin depth for different frequencies and materials with this Excel-sheet.

Frequency division and multiplication Excel-sheet (55 kB). Enter an oscillator or X-tal frequency and read the frequencies possible to derive by dividing and multiplying as well as mixing of two oscillators.

Transmission line reflection calculator. (25 kB). Calculate the various reflection parameters from your measurements with this Excel-sheet. I use it in my handheld computer/phone. Very handy. 

Resistance, reactance and resonance calculator. (25 kB). Calculate the various Ohm's law parameters, inductor and capacitor reactance as well as LC-resonance with this Excel-sheet. I use it in my handheld computer/phone. Very handy. I will update it with more functions. 

Parabolic dish calculation S/W for DOS-environment, Dish.exe (54 kB). Runs fine in an DOS-window in Windows 2000 and XP.
The following features are included:

Similar dish calculation program but as an Excel-file, Dish.xls (24 kB). NEW!!

 Wave guide and coaxial structure parameter calculation S/W for DOS-environment, Cutoff.exe (75 kB). Runs fine in an DOS-window in Windows 2000 and XP.
The following features are included:

 Smith-charts for the screen or to print on paper (A4 size) i PDF format. Standard B/W impedance Smith-chart (66 kB). Admittance and impedance Smith-chart in three colors (63 kB).  Unfortunately, the creator of the admittance/impedance Smith-chart made a mistake in the labeling of the susceptance sign. The upper part of the chart is capacitive susceptance and the label shall read -jB/Yo (not +jB/Yo) and the lower is inductive susceptance and the label shall read +jB/Yo (not -jB/Yo). I am truly sorry for any inconvenience this unfortunate limitation may cause you in an otherwise very useful tool.

Filter synthesis S/W for DOS-environment, Filter.exe (33kB). Synthesizes LP, HP, BP or BS filters with Butterworth, Chebyshev, Bessel or Gaussian (12 dB) characteristics. Swedish version. Words not very different from English, you will do just fine. Runs fine in an DOS-window in Windows 2000 and XP.

Radio equipment building descriptions

Beacon ID with PIC 16F84. A simple and reliable circuit for an radio beacon ID using the inexpensive and simple PIC 16F84. Still to be implemented!

Make your own connectors to 7/8", 1 1/4" and 1 5/8" low loss coaxial cable. Drawings for the whole process of making your own Type N (F) connectors using a lathe. The base is to start with a standard four hole flange Type N (F) chassis mounted connector and then making an interface to the heavy cable.  

Radio tech notes

Performance Measurement. Learn more about how to check your VHF-UHF stations performance by using ground noise, cold sky and sun noise. This mostly applicable for the EME-station but can be used for tropo stations as well. To be fully implemented! 

432 MHz dish feed analysis and comparison. Analysis of 14 different 432 MHz linear polarized feeds. Read this and get help in making the right choice of a 432 MHz feed for your dish. 
                                                                                        Post conference version of the "Unexplored Areas of 432 MHz Feeds" presentation from EME 2012, including new material (3.4 MB PDF-file). NEW!!

Phasing error analysis of four yagi antennas for 432 MHz. A analysis of how phasing errors affect the radiation pattern of four 9 el yagis stacked in a box confuration. PDF-file (800 kB).

Swapping of the anode cooler of TH308-type tubes. A description of how to remove and replace the anode cooler of the TH308 series of transmitting tubes. Here I give you a procedure to swap the anode cooler.

Formatting transmitting tubes and associated questions. A few hints on how to treat transmitting tubes that have been resting on the shelf for a while. If you do not take proper care of them you may cause injuries, beyond repair, to them. Here I give you a procedure to format or "burn in" the tubes. 

In addition to this a few other related questions with respect to transmitter tubes are addressed on this page.

Note! Working with transmitter tubes includes a lot of dangers, please be careful. 

Radio operating notes

Aircraft Scatter. Learn more about Aircraft Scatter (ACS). An propagation mode for VHF and up, independent of weather conditions. Still to be fully implemented!

Troposcatter. Make calculations on troposcatter paths by using the Excel-sheet of SM6MUY

A few other troposcatter links:


 This page is under development and the links may not work as expected. Check again soon and they can be updated!

Updated November 8st, 2016.