The Diason 50/6


The Diason set originated out of Melbourne in the late 1940's. This example was found in Ballarat in a particularly sorry state. Although intact, it appears to have been submerged for some time in mud and sand.

The circuit for the Diason can be found in Volume 9 of the AORSM (1950) but it does not correlate with this particular set.

The serial number for this set is #32AA1268 so I assume that serial numbers starting with 32 indicate a 32 volt set. Does anyone out there have a Diason with a serial number that starts with something other than 32? The valve line-up of this particular set is as follows: 6SK7 (RF), 6J8G (converter), 6SK7 (first IF), 6SK7 (Second IF), 6SQ7 (detector/audio amp) and 50L6 (output).

The 50L6 output valve filament is directly across the incoming supply with no dropping resistor. The other valve filaments are in series with a 100 ohm 20W resistor. I assume in this configuration the filament are probably running a little cooler than normal. I'm not sure about the converter valve either. The only circuits I have seen show a X61M for the converter. I have traced the circuit around the converter it seems to differ from that of the X61M circuit so I guess it's possible that this version did originally use a 6J8G instead of a X61M.

The only other obvious difference in the circuit is the tone control which comprises of a pot in series with a capacitor to ground in stead of a rotary switch.

Perhaps someone out there can make comments regarding the circuit etc.

I'd like to make this page into a before and after display to show what can be done with a set like this so here are the before shots of the radio, inside and out. Click on the images to get a better look.


Close up view of the front showing the lifting veneer and one of the knobs that a very hungry rodent must have thought would make a good meal.

Rear view of set as found.

Top view of chassis note mud around base of valves and on top of the IF cans and output valve.

Close look at top of chassis. Amazingly, none of the dirt seems to have gotten inside the IF cans or into the components under the chassis.

Even in its current state it still has a certain appeal. 

Inside the cabinet. It looks like the set had water and mud washing into it but the speaker is OK.

The dial is in very good condition.

The veneer has come off the from corners and is splitting on top.



I plan to track my progress here and display the completed set once I'm finished.


Last modified Sunday March 11, 2007