This is a free fortnightly newsletter about the New Zealand Net, which meets daily at 2100 NZT on 3535 kHz.
If you would like to be notified by email when a new edition is published, please contact ZL1NZ.
Browse our Newsletter Archive and List of Net Tips.
Featured key
By Neil ZL1NZ
Signal Electric was a significant US manufacturer of telegraph equipment, based on the shores of Green Bay, Lake Michigan, in the town of Menominee (current population about 8000).
The business began in 1892 as Menominee Electric and Mechanical Company, making crank telephone generators and other items. In 1919 it was reorganised and renamed Signal Electric Manufacturing Co. The company produced wireless and telegraphic equipment. It ceased operation in 1954.
Signal Electric made a few types of straight key. The one pictured above is mine, and bears the number “590” cast into the underside of the base, and “Signal Electric Mfg. Co. Menominee, Mich” stamped into the upper side of the base under the gap adjusting screw.
The key looks like a model M-100 (see advert below). I suspect “590” was the production batch number or contract number. If you can help with additional identification and dating of this key, please get in touch.
* If you have an interesting key for this feature, please send a nice clear photo and a few words describing it.
Quick notes
So we have now got to the point where the no-robots checks on some websites are so complicated only a robot could solve them. I have recently failed a couple of these tests. The one for creating a Microsoft Teams account required solving TEN puzzles. The visual version made no sense to me, so I tried the audio version, which required distinguishing subtle difference in ten pairs of sounds (all performed while listening on a tiny laptop speaker, of course). I failed that one too – so decided I actually didn’t need the software.
Sixteen stations checked into NZ Net on Thursday 5 September, which was a new record. The old record had been matched countless times, but it took a couple of years to beat it. The congratulatory QNC had been waiting patiently in my “Outgoing Messages” slot all that time, and was quickly dated and transmitted to all stations on that glorious evening. Yes, there is now a message for 17 check-ins, waiting its turn to be sent.
Gerard ZL2GVA was among those checking in for our record-breaking session. It’s great to have Gerard back on the net. He is still undergoing cancer treatment and most days is too tired by 9pm to join us, so we really appreciate when he can get on the air.
Still scratching your head about that key we featured in the last newsletter? The straight key that controls an electronic keyer? The explanation is in this edition’s video.
Photo flashback
Learning Morse Code at the Pratt Institute in Brooklyn, New York in 1917
Noise cancelling can really help
Background noise is about S6 with pre-amp on, but the RFI is S9 to S9+ at various spots across 80m.
By Paul ZL1AJY
At the start of winter, a nasty noise appeared on 80 metres, spread across the band at irregular intervals. I suspected this was a badly designed heat pump or electric car charger (there are quite a few EVs in our area).
Almost like clockwork, this noise would appear during the evening and cease after 11.30pm, 7 days a week.
I had a MFJ noise cancel box here, purchased many years ago for a problem on 40 meters which resolved itself before I had installing a secondary “sensing antenna.”
End-feeding a half wave on 80m as a noise source was the simple fix to get some RF back into the shack. So, out with the trusty nylon fishing line and round 3-ounce sinker, to throw a line over trees behind the property, This was used to pull back heavier cord which then had a half wavelength (on 3.5 MHz) of RG-6 tied to one end.
The RG-6 is simply used for antenna wire, with the internal wire and external braid wrapped together forming a single conductor. It’s cheap and very strong, with gel fill preventing water ingress.
A quick VNA check showed a quarter wave on about 1.75 MHz, i.e. a half wave on 80 metres.
The matching transformer (in waterproof container strapped to a tree) was wound on a T200-43 toroid. Nothing special, again using a VNA to check match from 50 ohms to 3300 ohms resistive on the bench.
A brief ‘in use’ test showed the match was slightly reactive, about 370 pf needed across 50 ohm input. I suspect this is because the transformer is not fed directly to ground, but via about 1.5 metres of wire linked to a 2-metre length of aluminium tube hammered into the ground.
The end-fed as a noise source works perfectly, and is also surprisingly good as an 80/40 antenna compared to the dipoles here.
The MFJ is connected to a K3 via the transceiver’s RX IN and RX OUT sockets, and switched in or out from the front panel of the K3. This arrangement avoids sending TX RF through the MFJ.
In use, the offending QRM can be pushed into the background noise without much effort. One interesting outcome is odd audio phasing on some signals with the MFJ in use, noticed using headphones.
The photo shows the end-fed matching transformer tied to a tree on our boundary. A toroid feedline choke can be seen and a green ground wire link. The old ladder is a permanent feature, almost hidden in foliage.
Net numbers
NR42 R ZL1NZ 45/42 AUCKLAND 0900Z 2SEP24 = AUG QNI VK3DRQ 21 VK4PN 13 ZL1AJY 6 ZL1ANY 27 ZL1AYN 10 ZL1BDS 13 ZL1NZ 27 ZL1PX 22 ZL2GD 19 ZL2GVA 1 ZL2KE 7 ZL2LN 6 ZL2TE 12 ZL3TK 13 ZL4BDG 1 ZL4GW 9 ZL4KX 15 ZL4LDY 22 TOTAL 244 QTC 30 = ZL1NZ
SDR receiver kits
I’m a member of Marlborough Branch 22. I had this crazy idea that some members might like to give homebrew a go, so I developed a simple 40-metre SDR kit (see Break-In, May-June 2024). The kit is brilliant – but no one was interested.
To get some small economies I ordered enough bits for 20 kits.
I’m keen to sell the kits to recover my outlay. I’m selling for $26 each which was the parts cost to me.
There’s a bit of info on the club’s website.
Morse challenge
In the following recording, you will hear the opening call for a CW traffic net. What is the full name of the net (6 words)?
Please send your answers via radiogram or email to ZL1NZ.
Answer to previous Morse Challenge
The station was SDJ Stockholm, sending its closing message in 2002. SDJ was one of the earliest wireless stations, having opened 100 years earlier, in 1902. Correct answers were received from G5VZ, VK3DRQ and ZL1ANY.
Video: Electronic keying with a straight key
In NZ Net News 140, we featured the MouseKey by Mark ZL1MRT. Among its intriguing features, this rehabilitated old J-38 key controls a built-in electronic keyer.
“How on earth is that possible with a straight key?” I wondered.
Mark explained to me that dits or dahs were triggered depending on how long the key was pressed. Pushing the key momentarily produces a self-completing dit, while holding the key closed a bit longer than a dit creates self-completing dahs as long as the key is closed. So it’s sort of the opposite to what we do with a bug where the dits are automatic and the dahs are created manually.
Mark very kindly brought his MouseKey to last weekend’s meeting of the Musick Point Radio Group in Auckland so I could try it out.
I expected to be flummoxed by it, but in fact it was really quite easy to use. After one quick run through the alphabet, we started recording the following video:
[The sidetone was very high-pitched and faint, so it was adjusted during editing.]
“Incorporating a Pi Pico into the key has made possible algorithmic tailoring of the timing for manually keyed dits and dahs,” Mark explained.
“Programmatically set to 20wpm, this constrains the operator to work within fairly tight timing limits and thus encourages a high level of keying consistency.
“Additionally, as an aid to learning to copy Morse, the keyer can simulate the transmission of compressed messages encoded á la MCB/CW (c.f. article in QEX Mar/Apr 2024). The transmitted letter sequences thus occur essentially as random 5-letter groupings suitable as practice for copying Morse at speed.”
Net tip
Most of our operators do a good job of zero-beating the net frequency. Thanks for your careful QNZ.
Those who are occasionally (or consistently) off frequency probably don’t realise it, so perhaps this advice will help.
Nowadays, “zero-beating” (or getting onto the same frequency as another station) is typically done with some sort of visual indicator on the transceiver, or by using the rig’s automatic tuning feature.
Even if you don’t have either of the methods mentioned above, your transceiver’s manual should explain how to zero-beat. Typically you would start by tuning the other station’s signal until its pitch is exactly the same as your sidetone. To avoid emitting a signal while doing this, switch off the VOX before keying.
For NZ Net operation, some operators might just dial the VFO to 3535.00 and think nothing more about it. That works most of the time (assuming the dial is accurate), but what if NCS isn’t on 3535.0? NCS may have shifted frequency deliberately, plus they may be using very narrow filters if QRM is bad. Bottom line, we need a way to get onto exactly the same frequency as NCS.
If you do find yourself a bit off-frequency, Net Control may remind you to “QNZ” or tell you:
QNH xxx (Your frequency is xxx Hz HIGH)
or
QNL xxx (Your frequency is xxx Hz LOW)
By the way, Net Control is never off frequency. 🙂 Their frequency is the de facto net frequency. If they are not on exactly 3535.0 then please zero-beat the NCS. Otherwise you may not be heard.
Another good way to check that you are on frequency, is to use an online SDR with band scope or waterfall, zoomed in to the NCS frequency.
Advertising archive
A page from a 1941 Signal Electric brochure
Suggestions?
If you have suggestions on how to make the NZ Net better, or things you’d like to see covered in these updates, please contact ZL1NZ. You might even like to write something for the newsletter.
Thanks for reading, and I hope to hear you soon on the NZ Net!
—
Neil Sanderson ZL1NZ, Net Manager
New Zealand Net (NZ NET)
3535.0 kHz at 9pm NZT Daily
Open the menu by clicking the “burger” icon at top right.
Many menu items can be expanded to reveal subpages by clicking on the arrow. Click again to collapse the menu item.
