Broadcast - 13 Sept 2026
The last couple of club room technical nights have had an interesting “under theme”, although not intended. It started off with Lionel VK7ZLB, bringing in some “so last century” pre-electronic-calculator memorabilia. They were in the form of card calculators. Those hand held pieces of heavy weight card stock that you could select a value in a little cut window by sliding along or rotating a moving piece of card and then reading of the pre-calculated printed results from another window.
A selection of card calculators were:
Industrial dissipation of power
3 phase motor, contactor and overload relay selection
Hewlett-Packard Mismatch Error Limits calculator for phase and SWR
PMG Relay spring contact timing and contact pressure adjustment calculator
A 1970s Radio Shack Ohms Law calculator incorporating amperes, voltage and watts
And of course an Australian Metric Conversion publicity promotions calculator, compliments of Charles Davis
Even a music related slide rule, for transposing musical keys and by the look of it, much more
Andre’ VK7ZAB also had a selection of conventional solid plastic slide rules that were mandatory ownership if you were pursuing a career in engineering or electronics.
Unfortunately none of us could find a copy of our “log table book”. That A5 little reddish coloured book that contained look up tables for Characteristic and Mantissa, does that ring a bell?
Importantly, all the above calculators show you the relationship between the information being selected and the result. Or possibly more succinctly a visual representation of a formula and the interaction of the variables on the result. What a blast from the past, before things became easier….
Even after fifty years, they still work, they are still legible and of course the non-existent batteries haven’t leaked!
Club room technical nights just wouldn’t be complete without a 3D printed offering by someone, the last tech night was no exception.
Colin VK7ZCF, firstly had a 3D printed speaker enclosure, including its mounting bracket, not un-like the classic Motorola vehicle extension speaker. The main difference being this version was grey, not the usual black or beige, but still about the same 140 mm square front dimensions though.
Secondly, was a 3D printed replacement instrument knob, measuring 80 mm in diameter, it was reasonably complex as he also incorporated a skirt and pointer into the design. It was intended for a hefty variable auto transformer where the possibility of obtaining a manufacturers spare part would probably have been zero anyway. Once again the original was black, but I think Colin’s offering in grey will certainly fit the bill.
And now for something not completely different, from Colin as well as Peter VK7PD, not 3D printed, but something that was printed or maybe silk screen printed on. By pure coincidence both Colin and Peter, turned up with a brand new Tee-Shirt and Hoodie respectively.
Colin’s Tee-Shirt, sported a large printed analogue transceiver meter movement with his personalised call-sign appearing immediately below. Peter’s Hoodie had “CQ DX” emblazoned across the front in two lines.
Both are multi-coloured, both are available from the web and both are perfect for contesting, DXing, or just showing off your passion for amateur radio, while staying warm in the process.
The web links are available in the text version of this broadcast:
Colin’s call-sign and S-Metre Tee-Shirt is available at “Etsy.com” and Peter’s CQ-DX at Tasmania’s very own phenomenal amateur radio resource site - Ham Radio DX: CQ DX Hoodie
A reminder, if you are interested in aircraft telemetry, don’t forget the NTARC club rooms will be opening to watch the live REAST YouTube presentation by Mogens Anderson, covering ADSB aircraft tracking and telemetry. It should answer any questions you might have regarding that short vertical antenna on the peak of the club room roof. See you on Wednesday the 23rd September, Doors will be open by 7:00 pm for a 7:30 pm presentation.
As usual pictures will be available on the NTARC Web site under “Blogs” for this broadcast. NTARC Blogs
UPCOMING EVENTS
CW course - EveryWednesday night, on 3.580 MHz from 7 to 7.30 pm. Your CW Coach for the evening is Nic, VK7WW.
On Air Test and Technical gathering - Wednesday nights, on 3.567 MHz from 7.30 pm.
Club Room Technical night - The next session will be Wednesday the 16th September and will commence at the usual time of 6.30 pm at the Club Room Archer Street, Rocherlea.
Club Room Special opening - ADSB live REAST presentation on Wednesday the 23rd September.
Coffee Morning - Held every Friday in the NTARC Club rooms. Time is from 10 am to noon.
Finally - If you have any items of news please email them to the Secretary at the following address news@ntarc.net all items to be received no later than 5 pm on the Friday prior to the Broadcast.
That’s all folks,
73, Stefan VK7ZSB.
