OZ on 160m

I made some nice QSO's on 160m, 1840 kHz, lately. Of course my longwire antenna is much too short for this band, nevertheless I was surprised by the amount of stations I could see in FT8.

Jan, OZ1ADL, rewarded one of the QSO's with a nice eQSL.

28 MHz activity

I hooked up my FT450 with longwire antenna to explore the 10 meter band. There is a lot of activity ! A lot of stations on 28.074 MHz  FT-8 as well. I made some QSO's. I received a remarkable eQSL card from SV3AUW from Kalamata, Greece. I think the homebrew PCB on his card shows a nice X-tal oscillator, right ?

 

73 from the past

I found a nice eQSL this morning from Urugay in my inbox. It dates back to 2006. In that time I was quite active with PSK31:

Medium Wave LPAM transmitter

I did some experiments with the receiver IC KT0936M lately. I built a simple SW and MW receiver with this chip. To be able to do some experiments with the MW radio I thought it would be a good idea to make a small MW LP (Low Power) AM transmitter. 

                            Medium Wave receiver with KT0936M

For reasons of stability I started with a 1015 kHz crystal oscillator. The modulation of the transmitter is done by a 5W LF amplifier TDA2030A. The output of the LF amplifier goes into the input of the small transformer in the DC supply line.

I used a 2N2219A  as PA stage. I think it delivers about 500 mW. A pi-filter provides the proper interface to the antenna.

MW LPAM Transmitter schematic

With this low power AM modulated medium wave transmitter I have a good radio signal in the house. Of course our radio liscence does not permit the use of this transmitter for broadcast purposes. 

MW LPAM transmitter 

The LF amplifier;

70 MHz Sporadic E contacts

This week now and then the 4 m band opened because of Es.

I made FT8 QSO's with Spain (EA6SX) and Greece (SV2DCD, SV2JAO..) on 70.154 MHz

One QSO has already been confirmed by eQSL:

Path to OH is also open once in a while;

Radio Caroline

Lately I have been experimenting with a KT0936M module on the medium wave. I discovered that Radio Caroline puts a firm signal strength at 648 kHz at my QTH. The music they play is from the 60’s-90’s. Like to hear their music through my 5 Watt tube amplifier 😊

Here   https://www.radiocaroline.co.uk/#648_am.html   you can read that Radio Caroline returned to the medium waveband on 648 kHz AM as a legal broadcaster at the end of 2017, after applying for, and being granted, the Ofcom licence for the Essex and Suffolk areas of South Eastern England. Radio Caroline is using an RF power of one kilowatt from a Nautel ND2.5 transmitter.

More:  https://en.wikipedia.org/wiki/Radio_Caroline

 

 

First steps in satellite communications

The Satrover QO100 transverter enables you to use the geostationary OQ100 (Es’Hail-2) satellite. I was able to explore this equipment with Gerard PA2G. With the use of an IC-705 and the satellite dish aimed at the OQ100 satellite (elevation 27 degrees, azimuth 153 degrees in the Rotterdam area) we were able to receive satellite SSB/CW/FT8 signals at appr. 10 GHz (converted to 144 MHz by the transverter).

Making an uplink at 2.4 GHz will be the next step.

SATROVER transverter and LNA/Helix antenna
 

Roger's Scrapbook

Some of my projects on this blog are inspired by the radiowork of Roger, G3XBM. I like his transverter designs in particular.

I found that Roger collected a lot of his work in his Project Scrapbook (currently issue 5). It contains a lot of nice experimental data and good projects.

You can find the scrapbook here:

https://sites.google.com/view/g3xbm4/book

Hope you like the scrapbook as much as I do.

QRV from Attica

During a recent trip to Greece (Attica, Agia Marina) I was able to use one of the radio repeaters near the capital of Athens. The repeater has callsign SV1B and is located on Mt. Pentelikon. RX frequency is 145.775 MHz and shift is -600 kHz. CTCSS is 88.5 Hz. 

The Quan Sheng porto worked fine and with callsign  SV1/PA2RF  I could made some clear qso’s a.o. with SV1IUY.

Platform for KT0936M experiments

The little KT0936M receiver IC has surprised me. To find out and explore the possibilties of this chip I made a simple platform.

A multiturn potentiometer enables me to select any of the more then 20 FM and SW bands. This KT0936M is a DSP chip and therefore frequency selection is very accurate. I  listened to stable, small band, 14 MHz CW signals (in AM mode).

Today I connected an LF amplifier with a TDA2050 IC. I was surprised by the quality of the sound.

Anyway, I have to discover a lot.

How can I display the exact receive frequency. There is no Fout pin. Also how can I receive Single Side Band signals. This chip does not have an IF since it it is a DSP chip. So, how can a BFO be added. At which operating frequency ?

Anyway (2), I am enjoying the reception of the broadcast AM stations from all over the world in the evening hours. The fading, the different languages, the memories..