This is something I’ve been considering doing for years and following a recent conversation with a good friend, I looked into it again and found this guide which was posted back in July 2023. In my box of stuff, I found I had a couple of GPS modules, one Adafruit and one of exactly the […]

The post I built a Stratum 1 NTP Time Server first appeared on QSO365.

I’ve been enjoying activating SOTA summits on 2m, and after visiting Glas Maol and seeing how far I could get with an omni directional antenna, and watching videos of people using a 2m yagi to get into England from the highlands, I wanted to build a yagi.

All my research pointed me towards DK7ZB’s designs, specifically the lightweight ones. I decided the 4 element design with a 1m boom was optimal between gain and practicalities. This has a gain of 7 dBd and a front to back ratio of 12 dB. It also has the advantage of being able to use it with 70 cms.

I went to B&Q and bought some 22mm PVC pipe, some wall clips, 4mm aluminium rods, and a 6mm aluminium tube. I already had some electrical connector blocks and RG58 cable at home. I made the boom a little longer than 1m, so I could hand hold it if I wanted to, otherwise it only needs to be 1m in length.

Dimensions from DK7ZB - using 4mm elements

	Positions along boom (mm)	Length of element (mm)
Reflector	0	1020
Radiator	260	977
Director 1	470	930
Director 2	985	910

VK1AD’s post on building a similar yagi helped me decide how to mount everything to the boom, and I set to cutting the aluminium rods and drilling the holes in the clamp. The directors are easy, as they just slide through the clamp as a single piece. The reflector is slightly longer than 1m which the rods come in, so I used the 6mm tube as a connector between two 4mm rods. Sounds good in theory but it’s tricky to get the rods into the tube - precision hammering needed.

The driven element used the connectors from inside an electrical connector block, zip tied and then glued into one of the clamps. I used some solder wick to attach the coax to and screwed the elements in on each side.

RG58 is a bit heavy but it’s all I had so would do. Whilst this was easy to build, it does mean the only way I can transport it is by unscrewing the elements. Not the best solution but I wanted to get it built vs. debating over other ways or buying more things. A common way others do it is with a box mounted on the boom and there’s a coax connector on it, so you can remove the box with driven element in one. My one has about 3-4m of coax on which is enough from the mast mounting position to having the radio on the ground underneath.

I marked the PVC tube with sharpie for the location of each clamp, together with numbers. I also put a mark in the centre of the rod on the directors so I could centre it if it moved about in the clamp. It’s all about 1m long and I found a thin bag to carry it in. It’s not the greatest but will do. I used bungees to tie it to the side of my backpack.

I’m using a SOTABeams tactical mini mast to support it. It’s 6m telescopic fibreglass pole that has more strength than my usual Carbon-6 mast. There are two conduit wall mounts attached to the boom, so the yagi can be mounted vertically or horizontally. It works well enough, although if I want to change polarisation I have to take the mast down and then put it up again. I could take out all the other sections I don’t need but if I’m only taking one mast on an activation I want the 6m in case I need to setup HF.

I 3D printed some guying rings and rope tensioners from this design and cut some cord to length for the mast. The 2nd lowest ring fitted perfectly on the bottom segment of the tactical mini.

First test was in the garden, listening to the 2m lunchtime net…so it received well enough.

The first outing was to Cairn William, where I’d set it up on the top. We’d arranged SSB activity on another summit, although that guy had to pull out, however, we’d also prepared the locals to listen out. I started with SSB and managed to make four contacts locally with it. I then flipped it to FM and made a few more. Including a nice summit to summit with Schiehallion, around 112 km away! I brought it out later in the day on Tillymorgan, and managed a contact with Helmsdale, around 100 km to the north…whilst the yagi was pointing south! Turning it around turned me from a 53 and a 59 by the chaser

I’m pleased with the results and think it worked rather well! It wasn’t too tricky to setup and use in the field, nor heavy to carry. It takes a bit of getting used to the length of it, especially when walking through forests as I kept catching it on trees and causing them to dump all their water onto my back!

I think a different way to connect the coax and the driven element would improve it, and maybe a dedicated mast that was just the right length would be better.

I did find this design for a 100g yagi that looks nice, and have saved a few links to 2m moxon’s. Not sure when or if I’ll make these, as I do like the convenience of the slim G. I also printed a clip for it, so it doesn’t flap around in the breeze.

I appreciate that the last post here was about the HamClock and I said I wouldn’t be providing a guide to building one but I’ve been asked by a few people if I can write some instructions, showing what’s needed from start to end so I’ve decided to do it. This is a long guide […]

The post How to set up a HamClock for your shack first appeared on QSO365.

Here’s a little project I put together on a whim about 18 months ago. It was my tribute to the unlicensed (i.e. pirate) beacon cluster around 4096 KHz. There were several of them operating in full force, with powers ranging from around 100mW to a watt or so a few years ago. Their heyday was about 20 years ago. They were located somewhere in the southwestern deserts of the US, and were powered by batteries and solar panels. The feller who placed and maintained them has stopped their upkeep and, as a result, most, if not all of them, are no longer operational. (There was a small group who also placed these beacons, and I believe they too stopped doing so years ago).

This little beacon, using a commonly available crystal, put out around 30 or 40mW, if I remember correctly, into a 51 ohm resistor as a dummy load. If it were to be connected to an antenna, which will not happen at this frequency, it would need a low pass filter. I haven’t posted the schematic here, for two reasons –

1. I don’t want to encourage unlicensed operation and
2. This particular circuit is a bit of a kludgy design, and not one I’d use anyway.

I’m posting the photos as a reminder that if you don’t have Manhatttan pads, or don’t want to make your own, then so-called “ugly construction” is a very viable way of putting circuits together. If you do it well, your circuits can be quite robust and long-lasting. One of Rex’s MePADS was used for the IC, but everything else was built ugly-style.

In the next overhead picture, you can see the ATTiny85 that keys the transmitter. Above and to the right of it, is a 78L05 that supplies 5V to the chip. Directly below the crystal is the oscillator transistor, which is keyed by the transistor to the left of it. On the right is the PA transistor. All 3 transistors are 2N3904’s.

Before ending this post, there is a key part of ugly construction that is worth mentioning. High value resistors (1MΩ and above) can be used as standoffs. To circuit components, they look like insulators. In this circuit, there are two 1MΩ resistors used for this purpose. I later bought 200 x 10MΩ resistors from Mouser, and will be using them as standoffs in the future. They won’t increase your current draw by any significant amount either. A 1MΩ resistor to ground from a point at 12V potential will only cause an increase in current consumption of 0.012mA. A 10MΩ resistor will have even less of an effect, incurring an increase of just 0.0012mA. That’s 120µA. I can live with that!

Anyway, that’s it. I hope this inspires you to get the soldering iron out and build a little circuit. A simple receiver or transmitter, a novelty circuit, or anything really. Building these little things and getting them to work is fun. Incidentally, if you’re interested in listening out for these unlicensed HF beacons, the best source of information is the forums at HF Underground. The forum you’ll want is the one called “HF Beacons” though there are many other great sub-forums there as well.

A few weeks ago I bought the official Raspberry Pi 7″ touchscreen display for a project which sadly didn’t work as intended, this left me with the unused display and a case. I started thinking about things I could use it for and settled on a shack clock. Long term readers of my site will […]

The post How to build a shack clock using a Raspberry Pi and a 7″ Touch Display. first appeared on QSO365.

After much research, I’ve decided what I’m going to replace the Hexbeam with. I’m aiming to put up a SteppIR UrbanBeam which will give me the same coverage as the Hexbeam with the addition of a folded dipole on 30m. At the same time, I’m going to replace all the coaxial cable with Messi & […]

The post New aerial – I’ve decided! first appeared on QSO365.

One of the greatest challenges for the typical Ham QTH is squeezing-in that low-band HF aerial for 160m or 80m.  Loading coils, loops, creative routing of the wires around trees …

The next step in our project is to configure our microHam station management system to support the new antennas and other components in our 6m antenna project. Each radio in our station (we have five that are 6m capable) has a microHam Station Master Deluxe antenna controller that is used to select and control all of our antennas. These units use the band selection and frequency data from their associated Transceivers to present a set of antenna choices and associated rotator, LNA, amplifier, and other controls to the user.

We are adding the following components to our 6m antenna farm that will need to be controlled by our microHam system:

• A 7-element LFA Antenna on our main tower
• Three stacks of 3-Element LFAs on our main tower
• A microHam remote TEN SWITCH antenna switch to select one of the above antennas
• Two Premamp Housings – one shared unit between the antennas above on our main tower and a second housing that will be added to our existing 7-element antenna on our VHF tower

Any of these antennas and their associated Preamp Housings can be used by any of the six Transceivers in our station. There are also two Elecraft KPA-1500 1500w amplifiers (one is shared) that operate on 6m and can be used by three of the five Transceivers in our setup. In this article, I will cover the configuration of our microHam system to support all of the new elements.

Remote Antenna Switching

I choose a microHam TEN SWITCH to handle switching between the new 7-Element LFA and the 6m Antenna Stacks that we will be installing. This switch is can be mounted outdoors on our tower and has good SWR, power handling, and loss performance at 50 MHz. I also chose the option to have N-connectors installed on our TEN SWITCH.

Control Interface Installation

The first step in this part of our project was to install two new microHam Control Boxes to control the new remote antenna switch and the two 6m Preamp Housings. These control boxes are connected to a control bus which allows the Station Master Deluxe antenna controllers associated with our transceivers to control all of our equipment and antennas. The microHam TEN SWITCH that we are using requires ten 12 Vdc control lines to select one of its ten antenna inputs. Each of the two 6m Preamp Housings requires a combination of two 28 Vdc control lines to manage its relays and a 13.8 Vdc line to power its LNA. The microHam Relay 10 Control Box is a good choice for controlling the antenna switch, and a single microHam Relay 6 Control Box can be configured to control the two Preamp Housings. I installed the two new control boxes and a DIN Rail Terminal Block for ground fan out on an existing section of DIN rail in our shack. Finally, I extended the microHam control bus to the new units and connected the control boxes to the 13.8 Vdc and 28 Vdc power systems in our shack, and set the addresses of the two new control boxes.

Next, we updated the firmware in the new Control Boxes. We configured their relays into groups for interfacing to the remote microHam TEN SWITCH and the components in the 6m Preamp Housings.

New Antenna and Remote Switch Configuration

The next step was to define “RF Boxes” in the microHam program for the 7-Element LFA, three fixed-direction 3-Element LFA Antenna Stacks, and the two 6m Preamp Housings that we are going to be installing on our towers.

With this done, we created an additional RF box for the microHam TEN SWITCH that will be located on our main tower. The image above shows how the switch is configured in the microHAM system. We also needed to associate the Relay 10 control box with the switch to enable the microHam system to control it.

6m Preamp Housing Configuration

The next step was to configure our 6m Preamp Housings. The image above shows the configuration of the shared housing installed on our main tower behind the microHAM TEN SWITCH.

The shared Preamp housing will be connected to one of the inputs on our antenna switching matrix shown above.

This arrangement allows us to use the 6m LNA in the housing with any of the 3-Element LFA antenna stacks or the 7-Element LFA antenna we are installing on this tower. One of the features of the microHam system is that it can understand and correctly sequence shared devices like LNAs, amplifiers, and other active RF components.

LNA Controls

The image above shows the configuration for the LNA control button that will appear on our SMDs. The configuration above creates a button and display to turn the LNA on or off when an associated button on one SMDs is pressed. This control will appear on the SMDs for any radio using one of the associated 6m antennas.

LNA and PTT Sequencing

We also need to configure a sequencing element for each of our 6m Preamp Housings. This ensures that the Push To Talk (PTT) lines and transceiver inhibit lines are properly sequenced for the transceivers, amplifiers, and relays in the Preamp Housing that is part of a path to a selected antenna. The microHam system automatically applies the appropriate timing and sequencing rules to all of the RF elements in the path based on the sequencer settings shown above. Configuring the sequencer also involved associating the appropriate relay control units on the newly installed Relay 6 Control Box with the elements in the sequencer timing diagram above. One item to note here is the 20 – 30 ms tail on the sequencing of the Preamp Housing relays when going from Transmit to Receive. This is done to allow extra time for any stored RF energy in the feedlines during high-power Tx to dissipate before bringing the LNA back into the feedline system.

We also added our second 6m Preamp Housing to the RF path for our existing 7-Element M2 Antenna on our VHF Tower and configured it similarly.

Virtual Rotator for Fixed Antenna Stacks

The microHam system has a Virtual Rotator feature which is a great way to control selecting between fixed stacks of antennas of the type we are installing. The image above shows the Virtual Rotator we configured for our 3-Element LFA stacks. The Virtual Rotator becomes an additional antenna choice that accepts a direction in the same way that a conventional rotator does. The microHam system figures out which of the available stacks would best match any heading selected and automatically switches the antenna path to the stack that best matches the chosen heading. This capability will be a great tool in VHF contests when we are working multiplier grids on 6m.

Final Testing

With all the configuration work done, I downloaded the final microHam program to all of our Control Boxes and SMDs and did some more testing. I connected one of our 6m Preamp Housings to the newly installed Relay 6 Control Box and tested the operation with our Transceivers. Everything worked as expected.

I also used the microHam Control App (shown above) to test the various combinations of 6m antenna selections and configured options. The image above shows the selection of the new 7-Element LFA we are adding. Note the availability of controls for the LNA in the shared Preamp Housing and the controls for pointing the antenna via the associated rotator.

The image above shows the selections and controls for the 6m Antenna Stacks. The Virtual Rotator choice (STK-VR) is selected in this example. Each SMD has a control knob that can be turned to any heading. When the heading for the STK-VR antenna choice is changed, the system automatically chooses the stack that most closely matches the chosen direction. Choices are also available to choose any of the three stacks directly (ex. EU-STK for the LFA stack facing Europe).

Another nice feature of the microHam system is its ability to use different antennas for Transmit and Receive. The example above shows a setup that uses two different antennas for Tx and Tx.

As you can probably tell, the microHam Station Master Deluxe (SMD) system provides many features for controlling complex antenna arrangements and shared equipment. You can learn more about the microHam SMD system and what it can do here. You can learn more about the programming and operation of the SMD components via the SMD manual.

Next Steps

We’ll continue to post more articles in this series as our project proceeds. Here are some links to other articles in our series about our 6m Antenna Upgrade Project:

• 6m Antenna Upgrade Part 1 – Plans for Antenna Enhancements
• 6m Antenna Upgrade Part 2 – High-Power Power Preamp System
• 6m Antenna Upgrade Part 4 – Building Antennas and Prep for Installation
• 6m Antenna Upgrade Part 5 – Antenna Installation and Station Integration

Our new LFA antennas and supporting equipment have arrived. The next step in our project will be assembling them and creating an adjustable mounting system for the 3-Element LFA antennas in our stacks.

Fred, AB1OC

The post 6m Antenna Upgrade Part 3 – microHam Antenna Control System appeared first on Our HAM Station.

It’s amazing what you find in a box, isn’t it? Often, you need to support the end of a Dipole/Doublet from a pole and need a simple solution that allows …