Sunday, 29 June 2014

GHz oscillator

With a BFR96 you can make oscillators in the GHz range. With a simple setup I could generate signals up till 1.3 GHz.
I used SDRsharp as a "poor man's" spectrum analyser to view the spectrum.
Here you see the generator makes a (very unstable)  1.28 GHz signal:

Circuit diagram; I used a BFR96 (that has a transition frequency of 4.5 GHz) instead of the BFR92 (transition frequency 5 GHz). DC voltage connected to R21 is 9Vdc.

Saturday, 28 June 2014

Car damage

This blog entry is not related to radio at all, but I want to share some pictures I recently made with my Canon EOS1000D. This Opel Manta suffers from minor damage. I think there is an interesting story behind the pictures that I do not know.

Besides the car pictures, I made more photoos in the recreation area Noord-Aa near Zoetermeer

Oude Meer, runway 36R Schiphol, July 3, 2014

Friday, 13 June 2014

Video test patterns

Some months ago I needed a device to generate my callsign and location on my ATV 23 cm signal. For this purpose I found and built the PicoOSD.
There is another possibility. Use a DVD player which has an USB interface and a composite video output to connect to the ATV transmitter. On a USB stick you can store video test patterns (or other pictures) and show them in a slide show for example.

With the program mentioned in the article below it is easy to generate test pictures as shown.

A small modification to the Telefunken DVD player makes a composite video signal available (the red wire)

Contact 17 and 19 of the SCART interface provides the composite video signal for you:

On the right hand side you see the yellow cinch plug that transports the composite video signal. I installed the cinch connector on the front of the DVD-player for easy access.

Sunday, 8 June 2014

6m WSPR signal reached Israel

Today was a nice, sunny day to clean up the garden. While doing this you can still excercise the radio hobby of course. Let WSPR do the work for you. Today I selected 6m for WSPR.

This was the result:

All stations that heard my signal were from The Netherlands. Except for one; Chris, 4X1RF, from Haifa at a distance of 3250 km picked up my 10 Watt signal at 50.294 MHz.

                                                              4X, Haifa

This is definitely a record for me on 50 MHz. It is not my antenna that get the honours. That's just a simple dipole. Must have been (double-hop) Es that realized the communications link.

                                         Dutch WSPR stations encountered on 50 MHz

Saturday, 7 June 2014


From the website I installed the latest version of SDR#.
This is version v1.0.0.1285. With the previous version of SDR# I sometimes experienced a sudden stop while receiving strong signals. This anomalie seems to be solved in this version which I run on my PC with Windows7.

This beautiful program enables you, while using a cheap DVB-T dongle, to receive the radio spectrum from 50 to 1.8/2.2 GHz with a variety of modulation methods (AM, NBFM, WBFM, SSB, DSB, CW). 
In the picture above, I selected part of the 2m band. I tuned into 145.575 MHz which is the repeater output frequency of PI3UTR.

The dongles are for sale at eBay for less than $20.
For example the one I bought for $12 (incl. free shipping) has a R820T tuner with upper frequency limit of 1.8 GHz.

Another example (incl. antenna and remote control for less than $10 incl. shipping)

The frequency range you can receive depends on the type of tuner installed in the dongle:

R820T: 50...1800 MHz
E4000: 52...2200 MHz

I have heard/seen a lot of signals with an indoor wire of 1.5 meter connected to the dongle. For example:

=> 2m and 70cm ham radio operators
=> ADS-B aircraft transmissions at 1090 MHz
=> AM transmissions in the aircraft band around 132 MHz
=> FM broadcast stations around 100 MHz