Broadcast - 25 June 2023
Those of us that have not been on the NTARC web site in the last few days would have missed an update in the “Notices” section that has been added. Something completely different to most of our postings, a project, something to actually construct, and according to the heading it is “Celebrating 100 years of Amateur Radio in Tasmania June 2023”. The Century “Cent” (1 Watt) 80m CW Transmitter Mk I by VK7WW (Nic).
Who better to describe what it is all about than Nic VK7WW, so over to Nic….
“I have the privilege of running the TechNet and TestNet for the Northern Tasmanian Amateur Radio Club (NTARC). The TestNet is a 30minute net on 3.580 MHz combined with a slow-Morse course. The TestNet gives QRP builders an opportunity to test their simple low-power (mostly CW) transmitters, even if they don’t know Morse code! (Just send a string of Vs – Beethoven’s Fifth’ – di di di dah)
To commemorate the Centenary Celebrations of 2023, I decided to build a simple crystal controlled, low power ( >1w), Morse code transmitter for 80m. It uses commonly available parts, is very easy to build, and it performs very well, with a ‘sweet’ clean signal.”
Now this is not your usual “look what I built”, here is some info and a few blurred pictures etc.
In my opinion it is an excellently presented project. Even if you are not into 80m CW it is well worth perusing the article. It is complete with legible circuit diagrams, component overlays, parts list and wiring instructions, interspersed with sharp close up photos of the constructed project to assist.
Here is a small excerpt from the “Building” section:
“Building is pretty easy. I mounted the prototype in a box I made from copper laminate from another project, seen in the photos. You can place it in a housing of your choice. Some builders mount it on another copper laminate board to use as a ground/“earth”, on which they can solder all components that go to ground. Much like what I did with my prototype. (See photos.)
Others may want to fix solder tags to all components that go to ground and bolt them inside a metal case.
I used a piece of single sided copper laminate (cut approximately to size) and a hand held hacksaw blade to create the separate sections – size detailed in the component layout page. I drilled mounting holes in each end of the copper laminate and screwed it to a wooden pallet so it couldn’t move, as I cut the pattern out with the hacksaw blade.”
Nic does an excellent job of methodically taking you through the construction of this project. One of the really important aspects of this project, apart from its simplicity is that at the time of writing, all components are available at Jaycar, yes you heard correctly, actually available locally at Jaycar!
Now I said it was simple, have a listen to the component count. Resistors: three, Capacitors: seven, Inductors: two commercial and one small balun former with only fourteen turns that need to be wound,
Transistors: two, nothing exotic just a general purpose BC548 and a good old BD139 used as the output final, some sundry parts like a switch, sockets and copper laminate PCB, a pretty small inventory really. The one important part is the crystal for 3.579MHz. Remember back to analogue colour TV days? It was the frequency of the ‘colour-burst’ used in the American NTSC system, as opposed to 4.433 MHz used in the PAL system that Australia opted for. This crystal is also available at Jaycar and allows the transmit frequency to sit very comfortably in the 80m band.
Now for assistance: Nic said “Good luck! Feel free to call in on the TestNet and TechNet 73 Nic.” Now you can’t be more helpful than that!
Evidently while testing the unit and operating from the Legana area on 3.580 MHz, between 7 and 9pm, Nic has had QSOs and reports come from Canberra, Gosford, Victoria, South Australia, Perth WA and even New Zealand. Not bad for just over 1 watt output!
As an addendum I noted that Nic called it the “Mk I”, this hopefully could suggest that there may be some more tantalising versions or modifications to come, keep checking the web site, you never know. Thanks Nic for your obvious enthusiasm and contribution to a Century of Amateur Radio in Tasmania and probably to the concept from one hundred years ago, “if you want it then you will have to build it…. “
Project link is in the text version.
Now continuing the CW theme, the WIA has just released on their web site the Harry Angel Memorial 80m Sprint – Final Results 2023 Contest. Peter VK7KPC, gained third place and a certificate in the CW Section, with only one contact separating the top three place holders, things were very close. The only other VK7 participant was Garry VK7JGD in the Phone Section. Congratulations to you both for waving the flag.
Competition link is in the text version.
The Wireless Institute of Australia (wia.org.au)
Reminder - the Club Technical night sessions held every second Wednesday night are now starting an hour earlier. Doors will open at 18:30 instead of the previous 19:30, this will continue during the winter months.
Hopefully it will provide more flexibility for those of us that live out of town and have to travel back at the conclusion of the evening, often in inclement weather.
UPCOMING EVENTS
The Club Technical night - The next session will be on Wednesday the 28th of June and will commence at the new winter time of 6.30 pm. That’s a one hour earlier start and running through to about 10.00 pm, at the Club room Archer Street, Rocherlea.
Coffee Morning - held every Friday in the NTARC Club rooms. Time is from 10am to noon and we look forward to seeing you all there. Why not pop in and join us for a cuppa, there is endless tea and coffee along with biscuits available for a donation. This is an excellent opportunity to collect your QSL cards.
The TestNet and TechNet session - Wednesday the 5th of July. TestNet/CW course on 3.580MHz from 7pm till 7.30pm…. and a TechNet on 3.567MHz from 7.30pm till about 8.30pm. Your host for the evening will be Nic VK7WW.
Midyear Social Evening - Wednesday the 12th of July. This will be in place of the usual “Club Technical night”. The venue is most likely going to be the Park Hotel in Invermay. Venue and time will be confirmed soon. Those who wish to attend please register the number of places required to the Secretary or on the registration sheet at the club rooms.
FINALLY - A reminder to all members that if you have any items of news you would like added to our weekly roundup, no matter how trivial, then please email them to the Secretary at the following address news@ntarc.net all items to be received no later than 5pm on the Friday prior to the Broadcast.
That’s all folks,
73 from Stefan, VK7ZSB, Secretary NTARC Inc.
