AH-4 to IC-705

 I can confirm that the IC-705 will connect to the AH-4 tuner without issue.

See also https://ve3ips.wordpress.com/2020/06/22/using-antenna-tuner-ah-4-with-ic-705-jk3azl-naoka-takaoka-english-translation/

Mag Loop - Upgrade

After several years of operating QRP with my Mag Loop, which can only cope with up to about 20w, I have now decided to invest in a vacuum variable capacitor and a better stepper motor.

It may take a few months for the capacitor to get here, so watch this space.

Antenna Rotator - Update

Way back in a post on the 5 April 2019, (wow, a lot of water has gone under the bridge since then) I provided my first update on an Azimuth and Elevation Rotator project that I was working on.  There were two options for code available at the time, one from Anthony Good K3NG and one from the School Amateur Radio Club Network (SARCNET), the latter from Victoria, Australia.  I decided to build the SARCNET rotator but in such a way that I could switch to the K3NG code if desired.  That time is nigh approaching.   

There have been some very good advancements with the K3NG code, two in particular.

• NEW! Satellite Tracking
• NEW! Nextion Display Support

These features are very significant as I would no longer need to use a PC or Pi to deal with the satellite tracking, the rotator, itself, can store up to 34 sets of satellite data  (TLE).  

The Nextion display is a great way of accessing the additional features without adding extra buttons and switches, thus saving on front panel real-estate.

The display has been ordered.

Adam, VK4GHZ has been busy enhancing the display, See above! As Adam states, 'LCDs and switches are so last decade!'

Keep an eye out for an update once we have the shack up and running again.

 

Mag-Loop - Controller- Part 4

The Mag Loop Controller  has an option to add an SWR Bridge into the equation.  I am nearing the completion of this addition. The SWR kit is by kitsandparts.com.

Mag-Loop - Controller- Part 3

The stepper motor has been installed and it's up and running.

You can see the backlash tuning working well as the capacitor will always tune in from the lower end of the band.

Mag-Loop Controller - Part 2

Monday (my day off) was a very productive day.  The controller is mainly complete, with just the SWR bridge (still to be ordered) to add, and three more buttons related to that.

The focus will now move to the stepper motor and the Loop itself.  I bought a very cheap stepper motor from Jaycar to try with my existing QRP loop with its duel gang capacitor.  The motor is 5v so I will need to make allowances for that but worth a try! I may also need to use the end stop option.

Watch this space.

Mag-Loop Controller - Part 1

I now think I have too many projects on the go! I've just started on an Automatic Mag-Loop Controller. Loftur (TF3LJ / VE2LJX) has done some amazing work, in developing a stepper motor controller that can take SWR readings from the antenna, along with frequency readings from the radio (via CAT port) and also stored memory data and tune the Loop, almost as fast as your ability to QSY.

It is a fairly elaborate project so may take a little time to get all the pieces working together. But we've made a start!

Loftur demonstrates his unit in this video below.

Monsoon and Lowering the Tower

The monsoon has finally come to Darwin, and with the rain there has been some very strong winds. I felt that it was time to lower the tower, as the last thing I want is to have my neighbours complaining about my antenna being in their property.  Some people have electric winches, or other elaborate setups.  Mine is quite simple, I just pick it up and lay it down.

Azimuth and Elevation Rotator - Part 2

After some setup issues the rotator and Gpredict on the Raspberry Pi are now talking to each other.  All that remains is for the electronics to be tidied up, some mechanical work to be completed and then to work out how to mount it, on either a speaker stand or tripod.

Azimuth and Elevation Rotator - Part 1

Over the last few weeks I’ve been spasmodically working on a rotator for my Arrow 2m/70cm (satellite) antenna.  There are two sources of code available that will accomplish what I’m hoping to achieve. One from Anthony Good K3NG (no relation that I’m aware of) and the other is from much nearer to home.

The code that I’m currently using is from Julie VK3FOWL and Joe VK3YSP.  They seem to be heavily involved in the School Amateur Radio Club Network (SARCNET), which has comprehensive build instruction for the Mini Satellite-Antenna Rotator (in several versions).  As is generally the case, I have deviated a little from their plans by using a Arduino Uno rather that a Arduino Pro Micro Board.

The most expensive single component so far is the case (at $34).  The software has several menu items that allow you to test and calibrate the unit. And you can also manually control it by entering the AZ and EL (in degrees with a space between them).  You do this with a RS232 (TTL levels) interface to a PC running a terminal program like Putty or the equivalent on a Raspberry Pi.

One issue was that the USB to TTL fob that I was using, did not drive the Uno RX pin to ground (but only down to about 2.5v).  The RX and TX pins on the Uno are also used for the USB connector and so the RX input requires a little additional encouragement to pull it to Ground. (Note: this would not have been a problem if I had used the Arduino Pro Micro Board.)  I added a couple of  FETs (2N7000) with resistors (10k)  to get the +5 to 0 volts swing required.

Once the mechanical work is completed, I’ll use a Pi running Gpredict ver. 1.4 (already tested) to track the satellites and send the AZ and EL data to the rotator.  Gpredict can also control the radio (taking into account the doppler shift).  At least that what I’m aiming for!  So watch this space!

Note: - In the video, I firstly entered '270 0' before entering '270 45'. You can see this as the rotator does not start to elevate until the second entry is made.

Links

School Amateur Radio Club Network

SARC Net Article

Radio Artisan K3NG

K3NG Arduino Rotator Controller

I thought I'd make a Rotator Controller for my 2m/70cm Arrow antenna.  There were a couple of options and I'm gleaning information from a number of sources. K3NG has some great Arduino Projects and so I've decided to use his code and some hardware options from closer to home (see SARCNET).

We have made a start with surplus parts, and more are on order from eBay.  OK, it's early days, but watch this space.

Mag-Loop

What a great view from the balcony, just love the Mag-Loop (the ocean and the sunsets, aren't bad either).  Inspiration for the Mag-Loop came from Dan YO3GGX, see his article here