Projects and developements from the past

This page covers several projects that I ran on my equipment, and just want to share that with you.  You must realise that I'm not a real inventor (not at all!) myself. More a rebuilder using adequate instructions, so most of the info given is not my own brain dump. Then I am a digital nono, but working with these conversion projects gave me some feel and touch.

Making this webpage makes me realise how many people have been looking into the possibility to get obsolete communication equipment available to the radio amateurs. They used their negotiation skills to arrest the parts (and prevent that they ended up in a shredder), others studied the design (or had already worked with these parts as repair/developement engineer) and came up with the solution to convert it into HAM radio's.
Sometimes the Amateur Radio Unions had the initiatives, but in more occasions it happened on personal title.

Compliments to those free spirits of HAM Radio!

Here below several Projects From The Past. Publication of this page brought back nostalgic memories...
I only show transceivers that are still in my posession.

The Teletron 813

With a transceiver named Teletron T813, originally in use with a countrywide 'greyhound'-like coach service (Maarse en Kroon, later Centraal Nederland), I found great pleasure in converting it to a PIC-controlled 2 meter transceiver.
I used it in the car for some time, untill I purchased the FT-90R.
The T813 was converted using a kit, provided by a goup of enthousiasts from the Eindhoven (homebase of Philips) region. It came in several boxes and a heavy metalic plate (to have it installed in these coaches).

There is no more reference available, unfortunately.... But in case Dutch is no problem: here is a condensed, yet clear Dutch user's procedure for the T813: T813 home made instruction file

The worse thing is the picture... Here held together by duct tape. But understand that you see in fact three parts, the way it was used in the car. The speaker (with volume control at the back), then the control unit on the dashboard. Below is the transceiver, laying on the floor in the car.
The great advantage was, that you could either tune a frequency, or select one of the ten programmed frequencies.

 The PIC controlled T813

The KF161-dig X

A very interesting (mobile) transceiver to convert or modify was the KF161-DigX. This Bosch KF161 was widely used, and has a simple user interface. Prominenty in the RH corner of the frontpanel is the 10 chanel rotary
switch. I had two KF-161's in my shack: one was programmed by using stacked IC-bases and diodes in a matrix. Later an EPROM became available.
Within the regional Veron department, there were several enthousiasts supporting the conversion. Conversion manuals were printed locally and lots of information was available.

For several years one was laying in my car as a separate unit to provide position information via APRS (

The Condor 3000 or SE 550

Condor 3000 by PA4DEN

This rig came around the turn of the century. I could have stated the year 2000 (or Y2k), but "Turn Of The Centrury" is more nostalgic, and that is what this whole page is all about, in fact.

This was a great developement for us humble HAMs. Because now there came clever programming possibilities and the use of memory programming and scanning in banks was new for me.
Programming looked quite an effort, but I found out that once I was doing it, I found the rhytm to program 10 memories in a row.

SE550 as it looks inside

Dennis, PA4DEN provided the chip that turned this unit into a UHF transceiver with good use of the buttons on the front. It came with a microphone and (I believe....) a speaker. If not, then one of the PG.540 group members could 'arrange' one.
I made my own user manual, for me to understand. And for my fellow non-digital minded HAM friends. Here is this piece of art, be it in Dutch.

This has been my major UHF transceiver for years, until the FT-8900 came in the shack.

MARC set conversion from 11 to 10 meters

Since March 3rd, 1980, Dutch Gouvernment legalised the use of the 27 MHz band. This became very popular, as now everybody could just buy and use a transceiver. Due to the popularity the 22 chanels were overloaded and communication was virtually impossible. After 2 years 40 chanels and 4 Watts became the new standard. But popularity dropped. These so called MARC-set became cheaper by the week.
About 90% came from the same factory and had virtually the same interior (pcb). Already in 1981 Heino, PA2HKR (now HB9CVG) came up with a modification that was stenciled and distributed locally in the Haarlem area. We started to convert MARC sets of which prices dropped to around NLG 75 and later even NLG 40 (so €34 and €18 respectively...!). In December 1981 it was published in Electron (magazine of one of the major Amateur Radio Leaguesin Holland), with a follow-on article in March 1982, containing tips and tricks.

The modification consisted in the replacement of a Xtal and the installation of an new Xtal oscillator containing the original 10.240 kHz Xtal to retain the 10 kHz grid. In our version chanel 22 became 29.700. Chanel 1 was 29.440, and chanel 9 became the home frequency 29.540 kHz. Note that spacing between chanels can be 10 or 20 kHz. A new HAM radio was born!

I found not any digital material on this conversion, but as I had documented old paperwork in maps, I have retrieved the stencil and the publication. I scanned it and you will find it here. Of course in Dutch.
For the visual aspects I have made several photo's.

Xtal pcb

  MARC modified to 10m
The new oscillator print and the view to the inside of the MARC set

There is a sequel to this story: see the next project by PA2HKR on a transverter to 70cm

MARC set - transverter from 10 meters to 70 cm

After the success of the MARC-set conversion (here above), Heino, PA2HKR developed a transverter from 10m to 70cm. In May 1982 the first stencils were distributed, and the project was started within the Project Group PG.540 community. Professional drawings were made, and after the succesful project, it was published in Electron in August 1983.
In May of that year a similar publication could be found in Electron, but then for a 2m transverter.

My own contribution was the addition of a VFO from 29 - 39 MHz, to use the transverter as a wide FM source on 70cm.

Transverter to 70cm
The transverter: standard components, keeping the price low for beginning radio amateures

MARC 70cm transceiver
The complete 10m/70cm transceiver. Used until the FT-8900 came in da house

Here it is: by using 2 Xtals in the transverter, I could select between 430 MHz and 433 MHz: 44 chanels in total. But chanel 9 is a home frequency: ending with .540 MHz

Antenna Tuner: the Z-match by Maurice PA9H (so not mine!)

I have no real pictures of my own Antenna Tuners, although I have constructed various. See picture from my old Shacks and you'll see the prove. One fellow Radio Amateur, Cor PA2MCE made one, a Z-match that worked fine on lower power settings.

Maurice PA9H Tuner
Z-match as  by Maurice PA9H

Maurice PA9H studied the publication, and built an improved version. My previous website version contained information (in Dutch, sorry...) and I give you the opportunity to review that article here.

The reason why I publish this (with permission), is the beauty of the construction!

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