Updates and Corrections

This page contains corrections and updates relating to articles published in CQ-TV.

CQ-TV issue: 182, 189, 193, 194, 195, 196, 197, 199, 201 , 205, 210

205 - Update: Mac NBTV programs.

I have recently updated applications, so I thought it might be of interest.

Playing with new 10.4 APIs for image and video processing I rewrote NBTV programs that I released a while ago to take advantages of those APIs.

NBTVSource is used to generate NBTV video. It can use various sources for input: video from iSight camera, still images (need to be in folder ~/Pictures/NBTV Images) and QuickTime movies (need to be in folder ~/Movies/NBTV Movies). Also it generates test patterns and produces slide show from still images. Now program supports 22, 32, 44 and 64 line video in monochrome and 3 color formats. Output is transmitted through audio port.

NBTVMonitor is a companion application to NBTVSource is used to display video received from audio port. Supports all formats that NBTVSource generates.

Both programs use CoreImage framework and QuartzComposer compositions to process and render video, so they will run on OS X 10.4 only. I am not sure if they will run on machines that do not support CoreImage and Quartz Extreme. My PowerBook happens to support them, so I have not try on Mac that does not.

Both programs are freeware and available for download from File names are NBTV Monitor and NBTV Source

Questions, comments, complaints, feedback will be greatly appreciated:

The pdf file shows actual images received by NBTVMonitor in different formats and resolutions. All images are captured from monitor screen.


A 500mW Linear Amplifier for 1249 MHz

In the middle column page 33 at the bottom it says "S11 new 4.32 +j13.13 S22 new 25.5 -j56.9.

These numbers are incorrect. The design was not based on these numbers at all and I am still not sure were they came from. The design was based on these numbers and these should replace the ones above for the sake of correctness:-

"S11 new 1.42 +j 13.2 and S22 new 10 -j22.58 ohms"

Basically if someone calculated the new numbers then the mistake would appear, however wether that is likely I don't know. Geoff Pike


A Low Cost Caption Generator

Can I advise readers that in my article “A Low Cost Caption Generator”, CQ-TV 201, that an error occurred in the component listing. SK1 should be a 6 pin mini DIN socket and not 8 pin as listed.

I would also like to thank all those builders who have complemented me on the unit's performance.

As the project has been so well received I have had a further batch of PCBs manufactured, details are available on my website , or by email - Regards, Steve Drury G6ALU

Pulse and Bar

In Fig. 8 of Part 4 of “A personal View of Digital Television” [ p. 33 of CQ-TV201], the legend on the wires to pins 2 to 9 of U8 should read U5, and not U6 as printed. Mea Culpa.


The article on the Shuttleworth 2002 event (page 29) was written by Trevor Brown.


Article Robot v Digital TX, page 10. There is a list of associated URLs at the end of this article. Becasue Word treats these a 'live' links, I was able to test them, however, in their printed form, the actual URLs are not visible. These are shown below: -

Initial Measurement of Tuning and Timing Parameters in HDSSTV Tx from AU to US
Decoding Beyond the Designed Distance
Summary of Australia_to_United_States Tests
Summary of Method Used
Coding Examples
Block Diagram of TX Side
Why 2 Levels of Coding
Block Diagram of Rx Side
Demodulated Waveforms
TX Operational Considerations
RX Operational Considerations
Images from Over the Air Tests
Summary of Accomplishments
Software Status

Article TX/RX Modules Down Under, page 5. For some unknown reason, the arrows disappeared from the transistor emitter in Figures 2 and 5. The correct circuits are shown below: -

Figure 2 Figure 5


Article 23cm Panel Antennas, drawing 3 on page 68

The lengths of the arms of the T splitter, shown as 28mm long, should be 39.25mm long if solid dielectric cable is used.


The SCART club would like to point out that its club callsign is G7SEZ and not G7SEX as reported by G1MFG on page 21 of CQ-TV 196. Rumours that G1MFG has a one-track mind have yet to be substantiated.


There is a mistake in the “Mods to the G1MFG modules” article. On page 40, column 4, “Installation”, step 4, the text should read Change R6 to 75 ohms (already done on 23/24cm Gold receivers), instead of referring to R7.

In the article “AFDs and Aspect Ratios” , there was a small typo in that the caption under the widescreen test card picture on page 10 read “4:3 picture in a 16:9 coded frame”, when it should have read “16:9 picture...”. . Thanks to Peter Vince for spotting this.


The software for the article on making super VCDs on page 23 of CQ-TV 194 can now be found at


FM radio microphone

The range of the microphone should be 8 to 10 metres and not 80 to 100 metres.

Mini 23cms aerial

The person who did the testing was G8CKN, Roy Powers, and not G8CNK. (editors typo!)


There is an error in the 625 to 30 line converter article IC Table on page 18. The correct table is show below.