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 ?
Ron's Radio Corner
PA2RF - Radio Frequency Adventures from Goeree-Overflakkee
Friday, 1 November 2024
Friday, 11 October 2024
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:
Tuesday, 23 July 2024
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.
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.
The LF amplifier;
Friday, 31 May 2024
70 MHz Sporadic E contacts
Friday, 17 May 2024
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
Thursday, 2 May 2024
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).
Saturday, 20 April 2024
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.
Monday, 8 April 2024
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.
Tuesday, 19 March 2024
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.
Friday, 9 February 2024
Little Medium Wave radio
From a popular supplier of electronic goodies, I purchased a tiny MW/FM radio (not a DIY kit). It does not have a loudspeaker but should be used with headphones. I was interested in the performance of the MW part of the radio.
And that really surprised me. It is a very sensitive receiver for the MW/AM band (530-1600 kHz) using a ferrite rod antenna. I thought nowadays the MW band should be almost 'dead'. But that is not the case. On this small radio I received a lot of broadcast stations past days.
To my surprise the IC covers a wide range from 500 kHz - 110 MHz! The chip has been designed to facilitate following bands:
- Maximum two FM bands with configurable FM frequency range within 32MHz-110MHz
- Maximum two MW bands with configurable frequency range within 500KHz -1750KHz
-Up to 14 SW bands with arbitrary frequency range within 1.75MHz – 32MHz
The KT0936M has a high sensitivity, high signal-to-noise ratio and low distortion.
KT Micro provides following values for sensitivity:
1.6uV EMF for FM
16uV EMF for MW
13uV EMF for SW
IC KT0936M provides direct and simple interface to support mechanical tuning. A pre-programmed low cost EEPROM can also be used to configure the radio band settings. No external MCU is required.
If you search on the internet for KT0936M designs, you can find out how the specific bands can be selected (use of resistor network). The IC should be useable for our radio amateur shortwave bands. At least a BFO has to be added to the design. .