Amber 4400 test set repaired

[fazer]

Here’s my Amber 4400 test set brought back to life. It’s a sweep function generator with sweep filter , dbm meter and plotter for displaying frequency and phase. Some capacitors one cmos 4066 chip and a bunch of contact cleaner.

There are many apps that do this today on a laptop but not much in 1976 so this was an answer. The guy that developed this in Canada also made the short lived Olive console. I’ll post some more info if anyone is interested. The scope is showing a 20 to 20khz plot with some markers. I should put this on an eq but it’s a flat sweep of a sine wave with a +\- 10db window.
View attachment IMG_3154.MOV
View attachment IMG_3154.MOV

 

[Harvey Birdman]

Hi Fazer, I have a 4400 that I need to repair, they are a very versatile test set when they're working properly. The main problem I've had with it in the past was the tantalum caps, was that your experience? Mine is the original 4400, looks like yours is the 4400A, can't remember what the the difference was between them. Amber also made a good Distortion Analyser. Cheers.

 

[fazer]

Hi Harvey. I’ve checked the tantalum caps and not run into problems with them so far but know they can be a problem.

I replaced the filter caps on the various power supply’s and a 4066 cmos switch chip. I also replaced a 318 in the function generator.

The main problem I ran into was the molex connectors had some female pins that had opened up and made intermittent contact on 2 J connects that I traced and tightened. All the shadow push switches were cleaned with contact cleaner and the nsprayed with cramoline gold and repeatedly exercised. Then everything started working correctly. I started to calibrated the A/B inputs and realized I needed to clean the switches. I’m going back to calibrate the other trimmers now but it’s working very well now.

 

[mjrippe]

I love my Amber 5500. I did not know about the connection to Olive consoles, but the fellow who started Amber later went to work for Audio Precision.

 

[JohnRoberts]

From my modest foray into test equipment design (Loftech TS-1), designing bench test equipment is the pinnacle of objective circuit design.

JR

 

[fazer]

I love my Amber 5500

Wish I had one. I have an old HP wave analyzer. A 302. It actual gives a reading of each harmonic but not total thd

designing bench test equipment is the pinnacle of objective circuit design.

Your the electronics designer JR. I mostly just use mine to repair all my old equipment. I need an intervention