AWA (Amalgamated Wireless Australia)
Excuse my indulgence but just let me give a bit of history about this AWA equipment ...
Once upon a time Australia had a thriving R & D AND manufacturing industry in the field of electronics. AWA was a major player in the industry (not forgetting we also had massive manufacturing facilities for STC around the Alexandria, Sydney area) and many technicians passed through the very large complex at Ashfield, Sydney on their way to even greater things.
These companies designed AND manufactured a very wide range of electronic components, modules and fully assembled equipment - now they have all gone! Poof, all those highly skilled jobs sent off overseas.
This test equipment was AWA designed, used AWA manufactured components (where possible) and used only the highest quality "other"components such as the capacitors, switches, rotary controls - primarily they used Siemens (Germany) in products such as this.
This equipment was so good that very prestigious companies like Marconi (UK) had this product imported to UK, re-badged and designated the TF2104 - that Marconi equipment is actually a fair dinkum AWA G232
The G232 (and it's partner the F242A) even to this day remains legendary World Wide for being extremely well designed, high specification test equipment that was built to remain reliable for years to come.
I am sad that while Australia today still has some of the finest engineering brains in the world, our manufacturing base has been gutted to the point where we are now extremely reliant on 3rd party countries to manufacture our high quality components, sub-assemblies and finished products.
HISTORY OF THIS G232
We ran an audio post production facility for many years and needed to have high quality test equipment to maintain the critical equipment in tip-top shape, specifically the Studer reel to reel machines. Funny enough we also used a couple of these G232's to create specialised R & D projects using DTMF (Dual Tone Multi-Frequency) audio signals.
Now way back in the 1990's this equipment was not cheap, in fact it was very expensive but by good luck we picked up a few of them via the infamous Australian Broadcasting Corporation auctions - when the ABC was forced to sell off their old equipment in order to ensure continued sufficient funding from the Federal Government.
So we had 3 of these G232's - all in perfect working order.
This particular G232 one day about ten years ago had an issue, no longer giving the audio frequency readout - all zero's only (with the appropriate decimal point depending upon the range selected)
About the same time, I closed down our audio post production business of 25+ years and went into semi-retirement. The "good" G232's were sold off (overseas) along with a lot of our other equipment.
I kept this one remaining G232 with a view of repairing, restoring and recalibrating it - after 10 years it still hasn't been fully repaired. I repaired the fault (7812 regulator) but not the damaged 4000 series CMOS chip(s) in the frequency counter section. I have come to realise that I will most likely never "get around" to fully repairing this equipment so I am now seeking a new home for this classic piece of Australian electronics design and manufacturing which even to this day has many uses in modern technology.
AWA Low Distortion Oscillator
Model: G232
Designed/manufactured here in Australia
Released to industry 1986 and remained in production until at least 1990 (from memory)
Frequency range: 10Hz ~ 110Khz
Frequency selected across 4 ranges
Frequency being generated shows precisely on the 3.5 digit red LED display
Low Noise (see screenshot of noise levels)
Low Distortion (see screenshot of distortion figures)
Floating (balanced) output (600 Ohm or 40 Ohm)
Rear square wave output can be used for sync with an oscilloscope
Combination stepped and variable attenuators allow for extremely precise output level settings (see screenshot of noise levels and output accuracy)
The level precision settings are by using 10 push switches (interlocking) plus the large variable attenuator with background scale.
Design temperature range: 0 ~ 50 C
Extremely robust case construction which is also designed to allow easy access to the "internals" - just 4 bolts for the top half and 4 bolts for the bottom half and you have FULL access.
Extremely well thought out physical design which makes for easy access, fault finding and service work (should these be required)
PCB is one large board and single sided
Instantly you can see the oscillator section is a large part of the PCB, the other side looks after the frequency counter/display primarily
Rack mount ears (custom made by the Australian Broadcasting Corporation workshops) are supplied - you need to fiddle around with these to get the spacing correct for a standard rack mount width.
If rack mount is not desired, the unit has feet on the base for benchtop use although you need a decent area to place the equipment in! It is quite large.
Dimensions: 425mm wide x 352mm deep x 134mm height (without ears fitted)
WHAT IS ONLY HALF WORKING?
First up, on that day (or soon after) when we lost the frequency display, I got straight onto the G232 to see what had happened.
There are 3 supply rails in this equipment, +/- 24V DC and +12V DC - Urgggh, the latter rail had gone very high! way way higher than 12V (the input to the regulator is 21V). The 3 pin regulator had fried itself and this distressed the frequency counter (based on 4000 series CMOS chips). You can see the current limiting resistors going to the LED segments have burned the board a little - things got a bit hot in there!
I changed the 7812 3 pin regulator and all was good with the world once again, at the least display came alive again but it just sat on 0000 - showing no frequency readout.
THE OSCILLATOR SECTION WAS UNAFFECTED AND STILL OPERATES EXACTLY AS DESIGNED
It is just that the frequency counter is not reading the pulses from the oscillator any longer.
I have confirmed this once again just today, the audio frequency oscillator is functioning perfectly, as are the level controls but the display will not show me the frequency I have set up!
My next step was to replace at least the offending 4000 series chip (or all of them which afterall have suffered significant over voltage for goodness knows how long)
I never got to this next step, tracing the pulses from the oscillator and see why the frequency counter is not counting - the display at least is still fine (shows all zero's with the decimal point moving depending upon the range selected - all segments working) and the 7 segment driver chip looks to be still working ok.
It would have been nice if the 4000 series chips were in machine sockets but it is not to be, so this will entail at least one chip being desoldered and replaced.
The 4000 series chips used are pretty stock standard, they are:
3x Motorola 14526
1x RCA 4040
1x RCA 4066
1x RCA 4078
1x Motorola 14543
1x Motorola 14553
1x RCA 4001
1x RCA 4013
2x RCA 4016
1x RCA 4011
1x Motorola 14518
1x Motorola 14521
Many are "garden variety" but some of those Motorola's might be a challenge. I do have 1x 14518 & 1x 14526 here (new) and will supply them if you think they may be needed (not Motorola though, this can be important - not all chips are made equal, even with the same type number)
A full manual for checking and calibrating the G232 is available online and I have a copy as well - all copies I have found are pretty rough when it comes to the schematics though - very hard to read.
COSMETIC CONDITION:
Only used indoors by Australian Broadcasting (Studio 31 actually) and we only ever had it it the workshop up on a rack, so the equipment is in pretty good shape. One scratch on the top and a couple of discolourations but that's about it - no dents or broken parts to the case.
Front panel is very clean
All labelling is excellent, including the level scale
All front panel switches working correctly with a positive action and interlocking is fine.
Collet knobs are undamaged
No missing controls, sockets etc
So there you have it, a great piece of Australian technology with very high specifications, an audio generator which could still see a lot of use testing the characteristics of audio pre-amplifiers and power amplifiers and of course providing a known level, low distortion, low noise audio source for alignment when measuring wow/flutter in conjunction with a good noise/distortion meter such as the F242 with old tape equipment.
