A nice surprise this morning in the office. A collegue showed some beautiful pictures of Canadian industrial heritage. Allthough off-topic, I would like to share these pictures which Guy took during his recent visit to the Heritage Park in Calgary, Alberta (Canada). Amongst others, they show steam locomotive 0-6-0, CPR2023 of the American Locomotive Company, Shop No 70388, manufactured in Sep. 1942.
eQSL sometimes really surprises me. This week I got this eQSL from Peter, 6W2SC. The card confirms a 20m RTTY QSO back in 2006 :-) QSO's with Africa are very rare anyway because of the simple fact that people can not afford money spent on a hobby. Therefore the number of radio amateurs is not high and I treasure each QSO made with Africa.
This week I did some succesful experiments with the 23 cm FM ATV transmitter with ALPS VCO. The transmitter provides about 30 mW to an 23 cm PA which delivers 1...2 Watts at 1.2 GHz. One of the tranmissions shows my testpicture at the PI6ZTM repeater:
I did not include PLL circuitry in the design. The circuit is straight forward:
The video branch contains: CCIR-filter, VCO ALPS 1679C and MMIC MSA-0886. August 12, I was able to test the audio part (7.02 / 7.2 MHz oscillator). It worked, but there was some 50/100 Hz hum. Also I found that results were better when the 7 MHz signal was injected just after the 50 k potmeter. The VCO can be tuned from 1100...1350 MHz. At this moment, the experimental circuit is soldered on unetched PCB.
23 cm ATV transmitter The ATV transmitter is connected to the Power Amplifier (design PA0VRE):
2 Watt PA with BFQ68 and BFQ136 The PA delivers its output signal to a homemade biquad antenna, connected with about 8 meters RG6U coaxial cable (75 ohms). More testpatterns:
To my surprise the transmitter is very frequency stable. No PLL circuit required !
On a fleemarket I found a nice, old camrecorder to provide me with moving images for ATV experiments. It is a Sony Handycam from around 1990. It is a camera/recorder using Video 8 tapes. At the time a revolutionary device because of its palm sized dimensions and good picture quality.