Constellation for the HP-720

The HP Jornada 720 is a Windows CE Handheld PC with the following specification:

Operating System Windows CE 3.0
Processor 206 MHz 32-bit StrongArm RISC
Display 640 x 240 pixel 65536 color LCD
Memory 32 MB SDRAM

HP Jornada 720

The following files are required to install Constellation on the HP Jornada 720:
Constellation 1.3 CAB (HP720)

Installation Instructions     
   1. Download the Constellation installation CAB.
   2. Use ActiveSync to establish a connection to the Handheld PC.
   3. Copy the Constellation installation CAB to the Handheld PC.
   4. On the Handheld PC open File Explorer and run the installation CAB.


Constellation for the HP-680

The HP Jornada 680 is a Windows CE Handheld PC with the following specification:

Operating System Windows CE 3.00
Processor 133 MHz Hitachi SH3
Display 640 x 240 pixel 256 color LCD
Memory 16 MB SDRAM

HP Jornada 680

The following files are required to install Constellation on the HP Jornada 680:
Constellation 1.3 CAB (HP680)

Installation Instructions     
   1. Download the Constellation installation CAB.
   2. Use ActiveSync to establish a connection to the Handheld PC.
   3. Copy the Constellation installation CAB to the Handheld PC.
   4. On the Handheld PC open File Explorer and run the installation CAB.


Constellation for the HP-620LX

The HP Jornada 620LX is a Windows CE Palmtop PC with the following specification:

Operating System Windows CE 2.0
Processor 75 MHz Hitachi SH3
Display 640 x 240 pixel 256 color LCD
Memory 16 MB SDRAM

HP 620LX

The following files are required to install Constellation on the HP Jornada 620LX:
Constellation 1.3 CAB (HP620LX)

Installation Instructions     
   1. Download the Constellation installation CAB.
   2. Use ActiveSync to establish a connection to the Handheld PC.
   3. Copy the Constellation installation CAB to the Handheld PC.
   4. On the Handheld PC open File Explorer and run the installation CAB.


Constellation - GPS for Windows CE

Constellation is Windows CE application that interprets and displays NMEA data strings from a GPS receiver. 

Constellation is not one of these new flashy moving map GPS applications.  This is because it runs on old Windows CE Handheld PC hardware which have limited processing power and it is written in Microsoft Embedded Visual Basic which is not blindingly fast (or even slightly fast).

What Constellation does do is provide a graphical and text display of NMEA data frames data received from a GPS receiver connected to the serial port.


Constellation was written in 2006.

The hardware that it is written for was manufactured as early as 1998.

Why would anyone waste time doing that?

Four reasons:

  • I had two GPS modules sitting on my workbench that really needed to be hooked up.  They had only been sitting there for two years.......
  • I had a pile of obsolete Windows CE Handheld PC hardware sitting in the corner of my office.  These machines had all run various versions of software produced in my day job but didn't have much of a future.....
  • The development tools for the old hardware are free (if you can find it.... the HP 620LX was a challenge... Embedded Visual Basic doesn't directly support CE 2.0.... anyone remember Embedded  Tools for Visual Studio 5.0 and 6.0.... I had blocked that out too until this project forced me to remember!).
  • It looked like fun.

Constellation is the result of a couple of evenings playing with Embedded Visual Basic 3.0.
The project has been interesting... especially:

  • Discovering trigonometry again.... it has been a lot of years since school and my day job doesn't have much call for calculating distances between lat/long coordinates or drawing compasses.
  • Discovering that the old machines can still do something useful (well fun anyway).
  • That Embedded Visual Basic while definitely not cool, with assistance from sites like DevBuzz and HPC Factor can do more than you might expect.

Installing Joomla 1.5 on Site5

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The web site is currently (June 2008) built using DotNetNuke.

I really like DotNetNuke, it runs well, is easy to understand and there is a great market of available extensions but I am considering moving the site to Joomla.

Why am I doing this?


Not because I necessarily think Joomla is better.... I guess I will find out on this point.... but mainly because I am trying to consolidate hosting of with my other sites (, and which are all hosted at Site5 - a hosting provider based on Linux.

My first hurdle was getting Joomla going.... if you take the "standard" install that Site5 will do through Backstage you get Joomla version 1.0.14 or similar. This was really easy to get going but I couldn't quite work out why it looked different from the Joomla one of the guys at work demonstrated. This is because the Joomla you really want is version 1.5.

To install this at Site5 you need to manually install the files.... bit it caused a bit of head scratching to work out why I couldn't get the web install to go... the answer..... .htaccess.

If you do a manual install into Site5 (and likely other places) you must:

1. Rename the htaccess file provided as part of the distribution as .htaccess (quite understandable that the install doesn't overwrite what you have but a bit puzzling for those not really used to configuring linux based web servers).

2. Also I suggest using PHP5 which many require the following line in .htaccess:


AddHandler application/x-httpd-php5 .php


Once these are done it works great.


Hope this helps someone.


FT-101ZD Electrolytic Capacitor Replacement

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I previously wrote about replacing the 450v Electrolytics on PB-1968. I wanted to replace all the capacitors on this board but had difficulty finding these in the usual retail electronic component suppliers in New Zealand.

After replacing the 450v parts I discovered that Australian RF Kit supplier Minikits are involved with the VK5 Hybrid Radio Group and also sell a kit of electrolytics capacitors for the PB-1968 board and a 6kv rated capacitor for the grid/plate circuit.

I thought the price of around AU$25.00 was pretty reasonable so have ordered it and will replace all the capacitors on PB-1968.


Old Radios and Vintage Cars......

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I am having a lot of fun working on the FT-101ZD and I think I can relate to vintage car owners a bit better.... 

Each step through the process, each panel you open, each board you investigate you find something that either needs to or can be tweaked.... 

The process is certainly interesting.  As a Microcontroller guy (3.3v and 5v are good... nothing to bite... no sparks.... just a silent wimpering death when you do bad things) dealing with vacuum tubes and high voltage capacitors if cause for a little anxiety from time to time.... is it discharged... will it bite?

 I have learned about the requirement to discharge capacitors (not the hard way.... the FoxTango group on Yahoo is a mine of information on how not to hurt yourself) and spent some time building a capacitor discharger from 10 x 1M 1W resistors in parallel.  This is based on the circuit at  The resistance value works out at 100k and 10W based on suggestions from Murray ZL3MH.  Never got the diodes and the LED to work properly but the rest of the discharger works fine.




Fixing the FT-101ZD Digital Frequency Display

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In my previous post I talked about my "new" Yaesu FT-101ZD.  I had purchased it knowing that the digital frequency display was faulty and the seller included a Jaycar frequency counter kit.  I wanted to keep the rig a bit more original and was planning to build my own frequency counter using an AVR (or similar) microcontroller and use the existing 7 segment displays (or replacements if they provided to be faulty).

My ZD is a -16 serial number so was in the first batch to use the new frequency counter based on the MSM9520RS chip.  From comment on it appears that failure of this chip is not uncommon.  There is also a kit for a PIC based replacement from Teruhiko Hayashi (JA2SVZ).

Having more than enough projects in the queue I decided to go with Teruhiko's kit rather than reinvent the wheel.

Having ordered, built and installed the kit I have no hesitation recommending this to anyone wanting to replace the MSM9520RS in their transceiver.  The kit arrived promptly (Japan to my rural QTH in NZ took 4 days), was very well packed, included printed instructions (even through they were available on the internet) plus extra data on pin mappings, voltages and resistance to be expected which would be a great help fault finding plus Teruhiko appears genuinely concerned that you will be successful with the kit... we had a number of emails conversations where he provided hints and suggestions... particularly around removing the MSM9520RS which with 40 pins can be fun to unsolder.... the easiest option (and what I did) assuming you don't want to keep the chip for a museum is to cut the leads to remove the chip and then clean the cut legs from the holes.

If you are going to build the kit you need a fine tipped soldering iron (it makes assembling the PIC/MSM9520RS adapter board without solder bridges so much easier if you iron is fine tipped), a solder sucker (to clean out holes on the PB-2086 frequency counter board) and a set of side cutters (so remove the MSM9520RS and to trip excess leads from newly inserted components).

Here are some photos showing assembly steps:

1.  The assembled adapter board that allows the PIC to be used in place of the MSM9520RS.


2.  The PB-2086 Frequency Counter board with MSM9520RS and other misc components removed and ready for replacements to be inserted.


3.  The PB-2086 Frequency Counter board with replacement components (excluding the PIC) and ready for installation.  Initial install was done without the PIC so voltages on the adapter board could be checked with no risk of damage.


4.  .... And the end result..... a working frequency display.  I still need to calibrate it which requires adjustment of the trimmer on the PB-2086 so will do this in the coming week by visiting a friend with an accurate frequency generator.  Looks good eh!


As shown in the picture there is a slight mismatch between the counter and the VFO dial... I am sure this will be corrected once the alignment is done.

My next project after consultation with more experienced operators of the 101ZD is to replace the electrolytic capacitors on the PB-1968 rectifier board.  These are getting on a bit and failure might have some significant downstream effects. 

The Fox Tango web site has some very interesting 101ZD information and one PDF of particular interest is a re-review by G3LLL. . I found this interesting because it makes specific mention to check that the fuse that is installed is correct (3 amp quick blow for 234 Volts in NZ) so any failures have less chance of doing real damage.  I checked mine and found the fuse was 7 amp!  Remember to check yours.......

The project list after the PB-1968 board is done includes.....

  • Building a dummy load so I can check the driver and final tubes are OK.
  • Getting an antenna tuner.
  • Rigging an antenna.
  • Getting it on the air.

Plenty to keep me busy.


Restoring the FT-101ZD

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The Yaesu FT-101ZD was brought on the market in 1979, as a  low cost alternative to the Yaesu FT-901ZD.... so it may not be a real boatanchor but is a bit of a classic.

I got my Amateur Radio license in 1997 and hold the call ZL1WJQ.  Most of my operating has been on 144mhz but recent changes to license regulations opened the HF bands without the morse requirement.  This and having plenty of space living in the country has me enthused to find a lower cost HF rig and have a play.... hence the 101ZD.

I found this on Trade Me... the price was right and on receiving the unit I was pretty pleased with the purchase.  It is in nice physical condition and was as described by the seller.


The main problem described by the seller was that the digital frequency counter wasn't operational.  The unit came with a Jaycar frequency counter kit (to be assembled)... a nice unit actually.... I already have the version 1 counter and this was version 2 with updated software and a built in prescaler.... I plan to assemble it but not for the FT-101ZD... I wanted to keep this more original. 

My original plan had been to build my own frequency counter based on an AVR and use the existing 7 segment displays but some research showed that a fault with the custom MSM9520RS is fairly common... the part is near impossible to obtain..... and that Teruhiko Hayashi (JA2SVZ) has produced a kit based in a PIC microcontroller that is a plug in replacement for the MSM9520RS. 

With assistance from the internet and PayPal I had the kit on the bench within 5 days of first making contain with Teruhiko.  Details on the kit and installing it in the next post......

When I first powered up the rig I noted that the panel lights for the dial didn't work although the meter lighting was fine.  Opening it up I found that previous owners had  on finding the dial light blown wired in an additional bulb (not replacing the existing ones) and this was dangling from a couple of wires behind the dial.... and had also failed.

Rather than replace with bulbs I decided to go the LED route so used some bright white LED's with current limiting resistors.

It was a bit of the fiddly job to get the old bulbs out and the leds back in place inside the rubber grommets.... without removing the whole front panel but it is certainly doable with a pair of old chopsticks to hold things in place and provide a bit of leverage.  I decided to replace the dial bulb at the same time.... LED's all around.

Here is the result......


No frequency display yet.... that is still on the bench is pieces but nice to see the panel lit again.

After all that I am not sure about the white meter light.... it seems a bit too stark.... the original bulbs provided a warmer yellow look.... just might have to try swapping the white LED for a yellow one and see how that looks......


MC145170 Control Software

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Last last century (around 1998 from memory) I purchased a PLL board from a company called DC Kits.  This board uses a Motorola MC145170 PLL and was programmed by a PIC microcontroller.

Wanting a bit more flexibility I wrote some simple PC applications that allowed the MC145170 to be programmed via the parallel port on a PC.

These applications and notes were originally hosted on and appear to have disappeared.... so is response to the periodic requests I get for the software and notes here they are:



When I first got my Technician Class Ham License (similar to Limited in the USA)  I was keen to get started and build some basic VHF equipment as my interest was more in the construction and experimentation than  operating 'off the shelf' equipment.

I found out fairly quickly that building a stable VHF oscillator was harder than it first appeared (to me at least).  I built a couple of FM radio microphone type transmitters that worked but drifted terribly.... and that was at 100mhz.... what was going to happen at 144mhz which was that target?

After lots of reading I finally decided I needed to go with the PLL controlled VCO to get the stability and precise frequency selection that I wanted.  The Motorola web site had lots of information on PLL's and application notes but the loop filter calculations and design looked a little out of my league without any real test equipment.

Note:  In the next section I refer to the EXP-1 kit from DC Electronics.  The software available on this page is not restricted to the EXP-1 kit.  It can be used with any MC145170 PLL controlled oscillator.

After a lot of browsing the internet a solution appeared in a kit from DC Electronics called the EXP-1.  The EXP-1 is a PLL experimenters kit.  It comprises a Motorola MC145170 PLL with loop filter and a preprogrammed PIC chip allowing selection of any frequency from 0..185mhz using the on-board keypad.

To build a complete oscillator the constructor needs to construct a VCO on the development section of the EXP-1 board.  DC Electronics provide some good oscillator examples in the application notes that come with the kit.

Constructing the EXP-1 kit should be straight forward for anyone with basic soldering skills and a reasonably fine soldering iron.  Comparing the parts with the circuit diagram helped prevent a couple of errors due to incorrect component references on the PCB and explains the couple of 'spare' parts that are left at the end.... a resister and a capacitor which the circuit shows are used in the connections between the loop filter/PLL and the audio input respectively. 

Having completed the kit is was time to build an oscillator. 

The application notes provide some good examples (although a little light on the theory of operation..... particularly calculating L/C resonant frequency with varactor diodes providing the capacitance) of VHF VCO's with recommended components for selected frequencies.  I picked the lowest component count option which required a Motorola MC1648, a shielded coil, 2 capacitors and a dual varactor diode (all of which can be ordered from DC Electronics with the EXP-1).

I built the oscillator on a small 'daughter board' rather than directly on the prototyping area.  This probably has an effect on the overall performance but surprisingly everything worked first time and after keying 14400 on the keypad and setting the appropriate frequency on my scanner there was the carrier......



PICAXE to Microchip Part List with Datasheet Links

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I was trying to answer some PWM prescaling questions on the Yahoo PICAXE group and needed a list of the Microchip part numbers used by each PICAXE version. 

It took a bit of digging but I came up with the following list with links to the Microchip datasheet for the parts.

PIXAXE MicroChip Microchip DataSheet
08 PIC12F629
08M PIC12F683
18 PIC16F627
18A PIC16F819
18X PIC16F88
28A PIC16F872
28X PIC16F873
40X PIC16F874

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