Time is never enough!

My blog have not been updated for so long... my apologies to my friends and visitors who follows my blog. At the moment, not much of project is done. My time is occupied with work and also caring for my little boy born four months ago.

He is now 4 months and definitely bring joy and happiness to me and my wife. I guess, my diy projects will be on hold for a moment. Maybe, done is the slowest pace ever....

UNUN

My recent project was making use of the Amidon T-200-2 core to make a UNUN for the vertical antenna.

Below is the picture for the mentioned project. However, I have yet to test it as I am busy with work at the moment. That is also the reason why there is not much update in the blog.



Sent by DiGi from my BlackBerry® Smartphone

TesT

Sent by DiGi from my BlackBerry® Smartphone

APRS... my new toy.. antenna project on hold.. :)

Okay, here’s the review for the Fox Delta products – Foxtrak & Foxview3..

I received the package and it is very well packed into a nice box. I actually bought one Foxtrak kit, one Foxtrak PCB and one Foxview3 PCB. Here, I will talk more about the Foxtrak and a bit about Foxview3 and the Byonics GPS2 receiver.

The Foxtrak (Kit)

In the above photo, you can see the Foxtrak PCB and the metal casing. FD offers this as free with the kit.

The photo below is the components for the kit and you’ll notice how they actually took some efforts to label each component in their respective plastic bag.

After verifying that all the components are correct, I fired up my soldering iron and started the assembly process. It was quick… provided you have a good clean soldering iron with some decent amount of flux.. With or without will take you there but I prefer to clean the soldering tip every so often before soldering any components..

A photo of fully assembled Foxtrak minus the jumpers.

What I found while putting it all together was minor but worth to be included in the documentations especially in the schematic. The LEDs in the schematic is labeled as Pwr, CD, GPS and Tx but did not state the LED colors. But it is up to individual preferences to choose whatever color you want.

The casing is designed to the Foxtrak dimensions and it fits nicely. However, there is some minor issue. Since the casing came with a PVC insulator, it is too thick and the hole for the Instant Tx switch is a bit too low. This causes the push switch get stuck in “on” position. You can overcome this issue by replacing the insulator with a much thinner material.

Programming it was easy especially when the Null Modem PCB is bundled in together with the kit. As stated in the documentation, you can use other firmware by changing the PIC.

Byonics GPS2 Receiver.

I have one unit of this receiver and upon checking from Byonics website, the pin matched the Foxtrak pinout. After all, TT & Foxtrak is basically similar. I selected 5V for GPS power by installing the jumper on H1 (please refer to the documentations, otherwise you’ll fry the receiver if you mistakenly feed it with 12V.

To my horror, the Foxtrak did not get any signal from the GPS2. I then decided to test it with TT4 (from 9W2RUT) and also the Kenwood D710 and it works. I even use the GPS monitor to grab the data from the receiver and it is perfectly it good conditions. Oh well… maybe the Foxtrak is not working… I then decided to use GPS Simulator (thanks to 9W2RUT for giving me the software) and the Foxtrak works too…

What the heck is going on??? Could it be the signal RS232 signal is too low from the GPS2?? Maybe… How did I solve this issue?? I actually added a MAX232 between the GPS2 and Foxtrak and it works !!!!!

Using the GPS2 with Foxview 3 has no issue since Foxview 3 have the MAX232 included in the circuit. This is where I get the idea…

Using Foxview 3 as Tracker & Viewer ( I can’t afford the D710)

If you plan to use it as a Tracker & Viewer, Foxview can do that but with some minor modifications and limitations.

The limitations are,… the beacon interval is not as intelligent as the EZtrak, TT or Foxtrak itself. It is fixed to the timing you set using the Hyper Terminal and it does not change when your speed is faster or slower… Maybe FD can combine the Foxtrak with Foxview (include the MAX232) for those who intend to use it as Tracker & Viewer.

As per the modifications to enable the Foxview to accept GPS signal, Dinesh ( from Fox Delta) had already included it in the 2010 version. This also includes the mods done by Benoit Matral (F4EYW) which improve the FoxDigi beacon reception. FYI, Foxview3 is a combination of FoxDigi & Foxview). Here’s the link to Benoit mods. http://groups.yahoo.com/group/foxdelta/message/248 or visit his website at http://f4eyw.free.fr/fxw3/foxdigi-mx614_enhancement.html

I did the mods on my Foxview 3 and I like it. The only downside is the beacon rate.

The documentation for the setting is also a bit blurry to me.. I guess someone can help to make it easier to understand. And perhaps, improve the firmware so the beacon is more intelligent like other tracker.

The mods to enable it as a tracker & viewer are also not properly explained in Fox Delta website. I only found it from here. http://www.enide.net/webcms/index.php?page=wb8wga-tnc

The Variable Capacitor & Magnetic Loop Antenna Project - update 2 Sept 2010

After some tinkering.... I decided to use a single cable for both RF and DC... I planned to make use of the FT897D ability to tune the antenna instead of having a separate box just to tune the variable capacitor. Since the FT897D has a built-in circuit to control the YAESU ATAS screwdriver antenna, it should be able to do the same on this project.

I took some gears from an old CD player and a motor, coupled it with the motor controller that I made sometime ago for the Screwdriver Antenna project. I still need to make the Bias-T circuit before I can test the motorized capacitor. So far, with manual tuning, I can tune to 10m & 20m. I decided to abandon the wide-band loop project as I realized it require a much larger capacitance. It is very tricky to get a high maximum capacitance while having a lower minimum capacitance...

The Variable Capacitor & Magnetic Loop Antenna Project

I finally decided to start the project after being delayed for a long-long time... getting a 1mm aluminum sheet is not so easy as most of the seller only sells 4' x 8' size.
I used one of the drawing found on the internet and cut the sheets using my DIY CNC router that I build a few years ago..
The loop will be made from a aluminum bicycle rim for now. In the future, I am planning to use 30mm aluminum tubes but will settle with bicycle rim for now..At the moment, I have not measured the capacitance of the butterfly capacitor as I do not have the capacitance meter. Will leave that to 9M2CF I guess.. During testing with the new capacitor, I can tune to 10m but unable to reach 20m.. I need to increase the loop diameter and will do that when I decided to rebuild it with the 30mm tube later...