SignaLink USBA few days ago I was super-excited when Kobus Conradie ZS1K notified me that my newly purchased SignaLink USB was in the post. I built a few homebrew interfaces and they worked very well, so well in fact that I was ready to consider working mobile and QRP while on holiday. My research indicated the SignaLink to be a worth while device (note my careful choice of the word “device” – see later).
I rushed home from the Post Office and opened the box. It contained the unit and some cables and a CD and instructions – a very good package. In minutes I was on the air and working in a “workbench” mode with wires flying all over the desk. It is a very good and very easy to install Sound Card (notice I’m saying Sound Card, because that is what it is). Works as advertised.
Then my problems started. I started looking for the radio control interface – a CAT interface so to speak. The piece that you use to control the frequency on your radio, and reads the frequency back for your automatic logbook on your computer. I searched for COM ports, I scoured the internet, I even made a cookie of myself asking Jason at TigerTronics Support for help. Eventually I dawned on me (Yes, I’m blushing here) that this is a Sound Card interface only, and not a combo Sound+CAT interface. Sigh. Back to the drawing board.
This is really not a big problem for most people, mind you. Once I plugged in a CAT cable into the second USB port on my laptop, everything sprang to life immediately and it works very well. I’m using HRD 5 (the last free version) and I was surprised at how easily the SignaLink integrated itself into my setup. Except for the fact that I needed two USB cables. On a two-USB laptop. That is the problem, I have to unplug the mouse to plug in the Sound Card or I have to lose the CAT cable, two out of three. Or I can get a 4-port USB hub, but that complicates matters again because I want to carry as little as possible with me in my bag when I go mobile or QRP.
For the moment the SignaLink can stay in my shack, it is a neat little device. But my search continues for a single-USB-cable-between-laptop-and-interface device. Any thoughts?
My new call sign arrived today – ZR6LU. Shorter and easier on PSK31 which is my favourite operating mode. Hope I don’t get tonge-tied the first few times!
From now on I am ZR6LU and not ZS6ALU anymore. I invested a lot in the old ZS6ALU call sign, I created this website, I built a following on some publications, I have a Gmail address. Shucks, I hope I don’t forget something. But if there is one thing life taught me, it is to move one. Don’t sit still. Hence, when the regulations changed the seeds of change were sown.
Karel Bezuidenhout says on Facebook Group ZONE 38 Amateur radio Chat: Geluk Leon. Vir diegene wie nog nie verstaan: Beide ZR en ZS is klas A. D.w.s. dieselfde status. Geen onderskeid. Juis daarom het my twee seuns ook besluit op ZR6K en ZR6O. Lekker kort en inderdaad meer gewild op die DX-bande.
Are you like me and most other Hams, where your needs far exceed your budget? Where your have-to-haves stretches far further than your pocket money? And on top of that, if you are inquisitive and like experimenting like I do, the shortage of money really hurts.
Now please understand what I am saying: I have a good solid radio with a fantastic antenna that works very well and gives me great pleasure. When I operate. Which is quite often. Nope. What drives me is this insatiable curiosity to know how things work, and to try to replicate the mechanisms until I understand them. The “second” radio projects. I’m not touching my main radio, no, but my second radio is used for all sorts of experiments. My second radio is often lying in pieces on the operating table with all sorts of measuring tools sticking out of it.
Thus the story starts with me looking for a new vertical antenna. The piggy bank is standing on zero, and the desire is standing at boiling point. Nothing that is advertised seems to come close to my budget. What is a man to do? However, the Comet CHA-250BXII that is advertised for around R4995 seems interesting from a variety of points:
It is a multibander. Essential for me.
It seems to be a clean design with no coils and traps. I like that.
It can be assembled in minutes
They say it doesn’t need radials. We will see.
It stands only 7 meters tall. Ehh, what did you say?
Reviews vary from good to bad. Most people think it is a good listening antenna but not a good transmitting antenna on the lower bands. The really attractive thing is the easy installation. It consists of a 7 meter high radiator, with a tin can at the bottom that holds whatever black magic it does. Looking further it appears that Iain Crawford VK5ZD had some trouble with his Comet CHA250 (the link has lots of pictures and information). Great article. Apparently he got some water in his tin can, so he decided to open it and see whats inside. My kind of man!
And once the can of worms have been opened, the design seems to be fairly simple 6:1 transformer feeding a NON_resonant element. Searching around I could find any number of people that have tried to build a similar vertical antenna. One of the best is Broadband Vertical [click here] by Martin Ehrenfried G8JNJ where he writes about his experiments with a CHA-250 style vertical. He compares various commercial verticals. His measurements indicate that no tuner is required for this CHA250-style antenna (just like the commercial version) and that it only needs a RF transformer. He follows that with a second article where he improves the design significantly – a must-read.
Look, this small little 7 meter high baby antenna is not going to perform like a huge tri-bander on a tower 40 meters above the ground. This is to be expected. But it works good enough and is very easy to construct. So I set out to make one from parts I have lying around. You can follow the slide show on my RigPics page. Firstly I decided to use 4x RFI Snap-On Chokes from MFJ that was intended to be used as RG-213 coax shields. They have inners around 10mm, and thus a few centimeters of 10mm copper gas pipe was scrounged. Cut the two copper pipes to stick out 2mm on both ends. For the inner cable I wanted a high voltage insulation, so I stripped the black PVC from a few centimeters of an electric fence high voltage feeder cable. This was fed through the two copper tubes. The one side only has two windings, the other 4 windings. The hardest part was soldering a piece of 1.5mmsq wire onto the copper tubes (they conduct heat very quickly away from the joints). Finally I connected it all up to a piece of 7 meter long electrical wire thrown up into a tree.
The SWR readings were reasonable and I could hear stations all over the band. As expected, on the lower bands the remote stations gave me lower S-readings although I could hear them well. This is exactly what Martin predicted.
7.060MHz 1.4
14.250MHz 1.1
21.250MHz 1.3
28.850MHz 1.5
This is an excellent constructional antenna, supported by lots of information on the internet. The fact that it tunes across all the ham bands without a tuner is a big plus for me. It is a good listener. The only downside is that it is not a particularly good transmitter on 80 and is marginal on 40. It is definitely in my backpack for my next weekend away. Enjoy the slides on my “RigPics” page.
Yaesu FT-707You know the phrase: “Dearly Beloved, we are gathered here today …” and just like in real life, you are getting a pretty photo of what my beloved Yaesu FT-707 looked like when she was younger, before she went SK. Today, sadly, she doesn’t look like that any longer.
Poking around the insides far longer than I should, it seems like it is a fairly common ailment that got to her: The display board. The receiving and transmitting seems to work fine but the indicated frequency runs all over the place and finally got stuck somewhere high up. And this presents me with a big dilemma: Do I sell; do I fix; do I keep (yes, my name is Leon and I am hoarder).
I made the big mistake of searching on the internet for solutions, and Teruhiko Hayashi JA2SVZ in Japan makes a drop-in replacement module that will cost me ZAR300 plus a bit of assembly (during which time I will not be able to operate). A working radio is worth lets say ZAR2000 and if I let it go for spares maybe I can get R1000. There is no magic in the numbers: Whether I sell or keep, it’s going to cost me about the same in money, all things considered.
The case for keeping it: My friend Hannes Kloppers yesterday said: Any radio that works is a good radio. It can be a great standby. You can do so much with it! It has a good working 100 watt amplifier!
The case against keeping it: You can only operate one radio at a time. Another collectors piece will just fill up my storage. To be honest, it is not going to get used for actual operating a lot.
I guess I’m going to have to make a decision before I pack it away in the cupboard “for a rainy day”. Once it disappears into the boxes it doesn’t come out easily.
HLA 300 PlusI don’t like linear amplifiers and I find my little Yaesu FT857D almost always puts out a hard, clean and clear signal that is good enough. I’ve never doubted the brave little radio would pull me through.
Until Sunday. Earlier the day I worked the Unions End expedition organised by the Adventure Radio Club [click here fore more info] under the callsign ZS3ARC on 40m. It was busy but I didn’t have any trouble to exchange 59’s with Martin ZS1SM and so I was quite chuffed with myself, adding the very rare grid square KG05 to my slowly growing WAGS collection.
Later that evening when the bands closed and they moved to 80m I thought it would be nice to make a second contact. More is better, right? So I called Martin. He was happily chatting away to some other contacts so the band must have been relatively open to him. Here and there he mentioned crashes or interferences but generally he was having good QSO’s.
So I called Martin again. This time I checked my equipment casually just to make sure everything is plugged in and so on. Martin chatted on …
The third time I called Martin he heard something through the noise but he couldn’t properly identify me and stuff, and we couldn’t complete the QSO. By now I realised that this logbook entry was going to take something a little extra, like a few extra WATTS.
Earlier this year I bought a HLA 300 Plus amplifier made by RM Italy from Sams Radio. The price was right, my power supply wasn’t. On a good AHH! it pulls more than 40 Amps and trips my 30 Amp power supply. However at that stage it already bends the needle on my SWR meter past the 300 Watt mark. So the little project was paused, waiting for the arrival of some shekels to upgrade the power supply. And while I was waiting I was happily adding more countries to my logbook using the 50 or 100 Watts of the barefoot radio.
But getting this grid square twice was very very important to me and so I decided to take a big risk. What if I kept my voice lower not to exceed the power limit? Very quickly I plugged the antenna across, the amplifier was already wired to the power supply. I went right down to 5 Watt on my Yaesu FT-857D, I switched the 3dB attenuator on the front panel of the HLA-300 in, tuned 10kHz lower in the band, and did a test call. Disaster! The power supply crumbled under the strain. I will not forget the disappointing click of the trip switch. Sigh. What now!
My antenna is a 80m horizontal loop strung between the trees and it resonates slightly higher up in the band. I pulled out my MFJ-941E Antenna Tuner (also from Sams – thank you Sam!) and pulled the obviously too high SWR down to something a little bit better. By now I was panicking and my hands were shaking so I remember that my settings were not perfect. Next time Sam, please sell me the automatic tuner version! A last check that I’m not connecting the wrong coax cables, and I sit down for a final test. If this doesn’t work …
Just over 30 Amps and 240 Watts and she holds! Lets go! Tune to 3.680 MHz, check my breathing, and wait for a gap. One call (with my eyeballs firmly locked on the ATU power meter) and Martin comes back! Yippee! He gives me a 57 because of QSB and noise but a very readable signal and we both confirm our entries in our logbooks! Crazy how happy I was with that contact confirmed! Logbook ZS3ARC 80m
Did I learn something from this exercise? Yes: Never ever give up. And that my little amplifier – that most Hams scorn because it is not a kilowatter – has given me a rare contact. What more can a Ham ask for?
Ham Radio Operators do it with more frequency and less resistance.
And:
Three guys in a car: A mechanical engineer, a Ham Radio operator and a MicroSoft employee are on their way to a meeting when suddenly the car in which they were riding breaks down.
“It’s probably the cable that opens the valve on the carb has come loose, pop the hood and I’ll have us back on the road in no time.” quipped the mechanical engineer.
“I doubt it,” replied the Ham Radio operator, “It has been observed that 83.2 % of similar failures result from the distributor contacts becoming corroded or misaligned, I’ll clean the contacts and we’ll be on our way.”
“No, no, no!” cried the MicroSoft employee: “This car is equipped with a state of the art computer, what we need to do is turn the key off, all get completely out of the car, then get back in and it should start like normal.”
Antenna SprayThe ultimate solution to HIGH SWR! Just use a can of this spray and all your problems will disappear!
I couldn’t help but smile and re-post this picture. I have no idea who the original author is, and I will fully acknowledge him/her if they let me know. I saw the picture for the first time on facebook on the page of David Lowe.
Just proves we are not a bunch of boring old timers, we do have a sense of humour!
88.5Hz Tone GeneratorJay my old Yaesu FT-480R is now operational on tone-protected repeaters! (Ed: Almost!)
From my bad location deep in the pits of Sandton I can just reach the Sandton repeater (145.700) up on the water tower near Wm Nicol Drive if I look north, and if I look south I can definitely reach the ZS6TJ repeater (145.650) on the Carlton Centre. The latter is a very convenient repeater for me to use as it will put me in contact with most of the people I need to talk to from my home QTH. The only problem is they were forced to put a 88.5Hz CTCSS sub-tone on the repeater because otherwise it was prone to false triggering.
And the problem is that my old FT-480R was built in the early 80’s, before the days of CTCSS. However Yaesu had the foresight to put a little connector at the back of the radio where a 35mV signal can be injected (in addition to a burst, but the two signals are paralleled) together with a convenient PTT signal marked 13.6volt. So the search was on for a CTCSS tone generator. I didn’t even bother to look for an original part as the radio is very old, although Yaesu makes mention of a FTS-63E device that should fit the radio.
It didn’t take me long to discover that OM Thys Maree ZS6MJM in Pretoria is building some excellent tone generator boards for the Magalies Club ZS6MRK. Very small and compact, it requires a 5-12v in and puts out a perfect tone that can be level-adjusted. On the bench it immediately gave me a beautiful tone, I adjusted the level and proceeded to install it in an open space in the radio cabinet. Fortunately the FT-480R has a bump on the bottom for the speaker, and there in the corner was a perfect hiding spot for the board.
I haven’t been able to trigger the repeater yet because I soon discovered that the power to the board was not 13.6v as the diagram says, and I suspect a loose connection or something. Nevertheless, I can highly recommend this little board as an add-on to an older rig as it has all the ingredients of a “Life-Extender” for older radios.
My back wallWell, I had to do this: Take a picture of my back wall, to explain how bad my QTH is located. In this view I am looking at the back walls of my neighbours 2 or 3 houses up. The river is on the right, and the power line on my left. The red arrow is where I will be standing for my next photo. River ViewIn the next photo I walked out my back yard towards the river, I turned around, and this is what I can see.
I am standing under a 88kV line, I can see the second line in the left of this picture, and I can barely make out my DSTV dish and the silver of my 2m CP22E antenna. All my antennas are just about halfway up the trees and a third up on the towers.
I have no chance to get a signal out, especially in summer when the trees have leaves.
To add to my frustration I am at the lowest point in the area. The municipal storm water drains are next to my erf, and my altitude is around xxxx MASL. Compare that to Sandton City, about 2km away as the crow flies, which is at xxxx MASL.
Vertical CP22E 2mSo, another sprout is springing up! This latest picture taken late on Friday afternoon, minutes after installation, shows my somewhat unsuccessful attempt to work VHF/UHF from my QTH. It is a 2m vertical (Diamond CP22E) that has 2 x 5/8 elements on top of each other. It claims a gain of 6.5dB and I must admit the build quality is very good. All the bits were in the box, so to speak, and it took me less than 30 minutes to mount.
The rest of the picture of the chimney shows my 2 SAT TV dishes, high up is the BroadGun Travelling Wave wire dipole, below that is the G5RV, and the 83m loop also passes through the view somewhere.
The BroadGun Travelling Wave wire dipole gives good results from 80m-10m at 100 watts and is almost permanently connected to my FT-840 for digital work. Depending on some random factors the loop gives slightly better results but not often.
The G5RV (in spite of the fact that it is standard and hasn’t been upgraded to the ZS6BKW specs) works extremely well. If I pull it up a little higher, or drop it a little lower, it just goes deaf! Exactly why I don’t know, but in this position it works very well and on voice I’m sometimes pumping a few extra watts through it – no problem.
The 83m horizontal loop is just strung from the trees and is interesting, it resonates on almost anything down to 6m. It is quieter that the G5RV and occasionally it is easier to work with.
But yes, the 2m vertical still doesn’t work. Connected to 15m of RG213 and mounted as high as it is I can just, but just, trigger the nearest repeater (Sandton). Simplex is just not possible as I am in a deep hole here and my signal just wafts over everybody’s heads (or antennas to be precise).
