Amber 4400 Multipurpose Audio Test Set
I would like to purchase or obtain a copy of the Amber 440 test set manual as well, if you can help me.
Thanks very much,
Dave
eeled@yahoo.com
425 691-3153
I would like to purchase or obtain a copy of the Amber 440 test set manual as well, if you can help me.
Thanks very much,
Dave
eeled@yahoo.com
425 691-3153
Just an update, thank you Ron and Graziano
I have got the beast working. In a fashion but working. There was extensive damage to every regulator in it. Either from being plugged in to 240V on the 110V setting or botched repairs by ehem "calibration houses" or general heat and aged capacitors.
Some of the repairs were particularly bad. Things like replacing one cap out of a pair on + and - supplies with a higher value. The 10V reference was a 317 with some resistors tacked on, lol. Someone had hacked/bent two of the brackets holding the back of the top PCB off! Leaving it flapping and shorting out on the regulator output transistors below. All sorted properly now
One question though, most of the tantalum caps used for decoupling were bad. I have bought enough to replace all 39 in the whole thing. Trouble is several are used back to back as coupling caps between sections. They are 10uf so two in series is 5uf. Do you think it would be best to replace these with one 4.7uf film cap? Modern ones easily fit in place of two crusty tants.
Cheers
Matt.
I have got the beast working. In a fashion but working. There was extensive damage to every regulator in it. Either from being plugged in to 240V on the 110V setting or botched repairs by ehem "calibration houses" or general heat and aged capacitors.
Some of the repairs were particularly bad. Things like replacing one cap out of a pair on + and - supplies with a higher value. The 10V reference was a 317 with some resistors tacked on, lol. Someone had hacked/bent two of the brackets holding the back of the top PCB off! Leaving it flapping and shorting out on the regulator output transistors below. All sorted properly now
One question though, most of the tantalum caps used for decoupling were bad. I have bought enough to replace all 39 in the whole thing. Trouble is several are used back to back as coupling caps between sections. They are 10uf so two in series is 5uf. Do you think it would be best to replace these with one 4.7uf film cap? Modern ones easily fit in place of two crusty tants.
Cheers
Matt.
Hi Matt,
Sorry to hear about the condition of your unit. I have / had three and none had the extensive problems of your unit. on the 4400, some regulator voltages were off which I traced to the DIL chip resistors changing value - replaced them with individual units. Apart from a bad digital chip here (now and then) and one bad tantalum, the units keep chugging away.
The swept sine function is worth the price of admission - use it ALL the time.
I've replaced the back to back electrolytics with the new Panasonic ECE series of Bi-polar caps. Highly recommend this series for many audio applications.
Charles
Sorry to hear about the condition of your unit. I have / had three and none had the extensive problems of your unit. on the 4400, some regulator voltages were off which I traced to the DIL chip resistors changing value - replaced them with individual units. Apart from a bad digital chip here (now and then) and one bad tantalum, the units keep chugging away.
The swept sine function is worth the price of admission - use it ALL the time.
I've replaced the back to back electrolytics with the new Panasonic ECE series of Bi-polar caps. Highly recommend this series for many audio applications.
Charles
Hi Charles, thanks for the tips. The digital meter on mine is a bit random now and again. I have all the digital ICs laying about so I think I will replace them one by one and see how it goes. There are several DIL resistor arrays on the top board and that got fairly toasty from the faults on the board below. I will drag them out and replace them wholesale Then hopefully I can calibrate it and start using it.
On another note, you wouldnt know where I could get one of the little push buttons with the indicator inside would you? My main power switch one was smashed off.
Cheers
Matt.
Then hopefully I can calibrate it and start using it.On another note, you wouldnt know where I could get one of the little push buttons with the indicator inside would you? My main power switch one was smashed off.
Cheers
Matt.
Hi There
!
I have recently acquired an Amber 4400a Multipurpose Audio Test Set WITH a service manual! However... unfortunately it hasn't got an Operating Manual and although I can get the signal generator side of things going, I would dearly love to be able to use the other functions to maximise the potential of this awesome beast!
Could anyone help me please?
Thanks,
Jason
!
I have recently acquired an Amber 4400a Multipurpose Audio Test Set WITH a service manual! However... unfortunately it hasn't got an Operating Manual and although I can get the signal generator side of things going, I would dearly love to be able to use the other functions to maximise the potential of this awesome beast!
Could anyone help me please?
Thanks,
Jason
To Charles, Matt, Ron, and Jason
Great to find you talking about these vintage test analyzers. I have three of the older Amber 3501 sets, none working properly, innerds are all different on all three, only two have internal transformers, only one seems 'close' to possibly being near working.
My similar HP339's also have problems (twelve or thirteen years back they both were perfect) and now I just acquired an Amber 4400 in untested / unknown working condition, which should arrive in about four or five days. I did note that one of the tantalum caps in one of my 3501 sets 'caught fire', so yes if they use back to back tants in the 4400's I would opt for film caps to replace them (if they fit). I'll let you know what I find when the set arrives.
Steven L. Bender
Great to find you talking about these vintage test analyzers. I have three of the older Amber 3501 sets, none working properly, innerds are all different on all three, only two have internal transformers, only one seems 'close' to possibly being near working.
My similar HP339's also have problems (twelve or thirteen years back they both were perfect) and now I just acquired an Amber 4400 in untested / unknown working condition, which should arrive in about four or five days. I did note that one of the tantalum caps in one of my 3501 sets 'caught fire', so yes if they use back to back tants in the 4400's I would opt for film caps to replace them (if they fit). I'll let you know what I find when the set arrives.
Steven L. Bender
Glutton for punishment I have a couple of 3501's as well, one works perfectly, the other does not meet specs, still need to dig into it and figure out why.
These are older models with the external transformer. It was the much later versions that put the transformer inside.
I suggest to Nichicon UKL as a tantalum replacement. They used tons of those ITT tantalum ecaps in them. Problem is they usually fail short circuit.
Good luck
Rick
I have a couple of 3501's as well, one works perfectly, the other does not meet specs, still need to dig into it and figure out why. These are older models with the external transformer. It was the much later versions that put the transformer inside.
I suggest to Nichicon UKL as a tantalum replacement. They used tons of those ITT tantalum ecaps in them. Problem is they usually fail short circuit.
Good luck
Rick
Hi Steven,
Absolutely LOVE my 4400. Also have an "A" unit along with a full set of extra boards. Don't remember having a problem with tantalum caps but have replaced a few IC's here and there. When you get your unit I first suggest checking the regulators on the 3 boards. The top and bottom board are easy to get to. To get to the middle board, remove the top and the top board (by taking off the right-hand pot knob/nut/washer and removing the 4 board screws. The top board can then be slid back and tipped/propped up from/by the front. Leave it plugged in and just insulate it from the middle board using a piece of plastic.
Check the supply voltages on each board. I remember finding a problem with the +/- 7V supply. Amber used an IC resistor network to set the regulator voltage and some of the resistors had "wandered". Was able to substitute lead-mounted resistors fairly easily. Then suggest checking out the meter section; followed by the (function) generator section; finally the digital memory / sweep section.
Have fun
Charles
Absolutely LOVE my 4400. Also have an "A" unit along with a full set of extra boards. Don't remember having a problem with tantalum caps but have replaced a few IC's here and there. When you get your unit I first suggest checking the regulators on the 3 boards. The top and bottom board are easy to get to. To get to the middle board, remove the top and the top board (by taking off the right-hand pot knob/nut/washer and removing the 4 board screws. The top board can then be slid back and tipped/propped up from/by the front. Leave it plugged in and just insulate it from the middle board using a piece of plastic.
Check the supply voltages on each board. I remember finding a problem with the +/- 7V supply. Amber used an IC resistor network to set the regulator voltage and some of the resistors had "wandered". Was able to substitute lead-mounted resistors fairly easily. Then suggest checking out the meter section; followed by the (function) generator section; finally the digital memory / sweep section.
Have fun
Charles
Glutton for punishment
These are older models with the external transformer. It was the much later versions that put the transformer inside.
I suggest to Nichicon UKL as a tantalum replacement. They used tons of those ITT tantalum ecaps in them. Problem is they usually fail short circuit.
Good luck
Rick
The external transformer was to make room for the batteries. I have one that mostly works. One damaged switch which doesn't look easy to fix and it almost meets specs.
I would like a copy of the 4400 manual if there is a PDF available.