The CDG2000 is based on a modular construction. Most PCB's are standard 100mm x 160mm eurocard size, which fits nicely in ready made tin boxes.

I made some prints of the component placement drawings which fixed to the tin boxes allowed me to try several combinations. One main consideration was to place the synthesizer as far away as possible from the front end and IF module, and to ensure shortest possible connection between modules.

Would all the modules fit into my favourite housing? Well that was because my main concern, because I had early decided that design should be a key element in this construction. Some years ago I got hold in a number of 19" housings with nice rounded corners like the famous Heathkit from the 60's.

I spend a lot of time moving the modules around, and finally found what I believe to be a very good solution. With a little ingenuity there was even space for the power supply and a 100 watt PA stage.

Another main consideration is performance. The CDG2000 is designed to be a high performance transceiver. Naturally I wanted to maintain this performance.

It is my experience that electrical instability often derives from mechanical problems. A rigid chassis construction solves many problems before they arise so I decided to make the chassis of 3 mm aluminium.

Maybe overkill but taking into account I also wanted to incorporate a 100 watt PA stage and a power supply for the entire transceiver, I believe this decision was the right one.

Modules are mounted using 3 mm countersink screws. Actually the tin boxes rests on nuts, which creates a small gap between the tin box and the chassis, which allows for cabling.

Note the 3 countersink screws on this picture. Space was limited and did not allow for traditional bolt mounting of the large toroid mains transformer.

The trick was done using 3 spacers as can be seen on the pictures below.

The mains transformer delivers 2 x 33 volt 250 watt. The two 33 volt windings are connected in parallel and drivesd the 100 watt output stage.

I have then fitted extra windings to get the other voltages required.

The power supply is spread out on 4 PCB's.

In the upper right corner a small relay board can be seen. This is used to switch the mains supply voltage to the power supply. A small 12 volt PSU unit is connected to the mains in standby. This voltage is switched form the front plate pulling the mains relay.

The PSU is build around LM317 voltage regulators. The main power requirement is on the + 12 volt supply, which is divided into two sections, one for RX and one for TX operations.

For heat dissipation this last PCB is mounted on the rear wall of the chassis close to a large heat sinks.

The completed power supply mounted.

To the left the front End, IF and preamplifier modules.