Same here with all the options, I have 3501-03115. The manual is issue 04, October 83. I got it from manuals Plus a few years ago.
The service so far has been those blue ITT tantalums going short. One was in the PS can, so that was a PITA to find and get at. I manged to replace one from the top side.
Good luck with the GPIB coding Demian . It was along time ago I did that stuff.
The service so far has been those blue ITT tantalums going short. One was in the PS can, so that was a PITA to find and get at. I manged to replace one from the top side.
Good luck with the GPIB coding Demian . It was along time ago I did that stuff.
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I have manual issue 9 from April 1988, the last known version. I was the service manager at Allan Crawford Associates the Canadian Rep. We sold these to various government contracts and provided service after the closure of Amber by Neutrik. A lot if not most of the circuit design was the work of Ed Meitner.
Hi Murray.
Do you have a 3501?
Nice to know a bit of history about Amber. I recall Allan Crawford from the old days. At one time I worked in the cal lab at Motorola. I can see now how you have all that nice test equipment. Funny how you posted a pic of your test bench setup, in the TO club thread, showing the HP11715A test set hooked up to the 8904A. I just got mine 11715A fired up this week. I had the main assembly with no case/PS so had to do some metal bashing to make a case for it. We can discuss this stuff if we get together in Scarborough
Cheers
Rick
Do you have a 3501?
Nice to know a bit of history about Amber. I recall Allan Crawford from the old days. At one time I worked in the cal lab at Motorola. I can see now how you have all that nice test equipment. Funny how you posted a pic of your test bench setup, in the TO club thread, showing the HP11715A test set hooked up to the 8904A. I just got mine 11715A fired up this week. I had the main assembly with no case/PS so had to do some metal bashing to make a case for it. We can discuss this stuff if we get together in Scarborough
Cheers
Rick
I'm going to bring my 3501 and 5500 to the AES swap meet and try to find good homes for them. I just have more analyzers than I can store in my shop. Also other excess sound cards and the like.
AES swap meet for SFBay, may be interesting to others: Audio Engineering Society San Francisco Swap Meet Tickets, Sat, Apr 7, 2018 at 10:00 AM | Eventbrite
AES swap meet for SFBay, may be interesting to others: Audio Engineering Society San Francisco Swap Meet Tickets, Sat, Apr 7, 2018 at 10:00 AM | Eventbrite
I received my 3501a from the ebay auction last week and was pleasantly surprised. It appears to have never been opened, the original cal tag is covering one of the cover screws. Its also in good cosmetic condition and works very well, -102dB @ 1kHz in loopback and it measures my tweaked HP339A's oscillator as -106dB. I need to add a couple of 4 pin headers to the oscillator board so I can move my 358 freq meter between the two units I now have. Its nice to have a spare!
You should recap it before putting it into regular use. There are a couple of tantalum drop capacitors as well as the PSU electrolytics that should be replaced. (Not too bad a job)
I had one of those tantalums catch on fire, fortunately I was able to get the cover off and extinguish it before any real damage was done.
I would probably replace the tantalums with Oscons or similar.
I had one of those tantalums catch on fire, fortunately I was able to get the cover off and extinguish it before any real damage was done.
I would probably replace the tantalums with Oscons or similar.
Murray and others, I have several 3501's and 3501a's. One problem is smoldering 10 if. tantalum caps, so far, I just clip them out - there are plenty on each board, and those parallelled film caps, and the ceramics, so a few missing really won't be a problem. I'll get to replacing them when I find the time.
I also find that when moving from 'level' to 'distortion', the meter goes down below the default Zero point and pins on the lower stop. None of the manuals seems to address this problem which I think throws off readings by some significant amount. Anyone have any ideas??? Does this indicate improperly adjusted trim pots V2001 - V2007???
I noticed on some units that the output transistors MPS-U07/MPS-U57 were changed, to MJE15029/MJE15030's but I am not sure if this was a good thing, as the replacements, in my experience, do not match as well in terms of Hfe. Could this be the source of the downwards offsets??? I really don't know!!!
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Just out of curiosity,do you think a low-leakage electro would be a viable substitute? I appear to have a large surplus of Nichicon UKL's......
With respect to the analyzers performance and reliability,would there be any point in replacing the original tantalum's with new tantalums? The originals,despite some spectacular later failures,seemed to last a fair bit.
As for the UKL caps,they are known for their low-leakage characteristics,not too sure about impedance. The datasheet doesn't reveal much....
http://www.nichicon.co.jp/english/products/pdfs/e-ukl.pdf
As for the UKL caps,they are known for their low-leakage characteristics,not too sure about impedance. The datasheet doesn't reveal much....
http://www.nichicon.co.jp/english/products/pdfs/e-ukl.pdf
Just 120Hz loss tangent and that's not too impressive particularly in the low voltage parts.
I would recommend replacing them with Oscons, equivalent modern Tantalums or low impedance AL types. Looks like you'll be buying something, the expense will be minimal and you probably won't have to do it again.
I would recommend replacing them with Oscons, equivalent modern Tantalums or low impedance AL types. Looks like you'll be buying something, the expense will be minimal and you probably won't have to do it again.
This is what I did. I used 35V Tantalums in place of the original 25V parts. My take on this is that if they last as long or longer than the originals did then I'll probably be long gone before they need replacing.
Anyone have a hard copy of the 3501 manual? The reason I ask is that the manual posted online is missing Schematic #2 in the series. If anyone has a hard copy of the manual can you scan or post a picture of that page here?
I still have a mild noise problem in one of my 3501's and I'm trying to pinpoint where it might be coming from. I just realized one of the schematics is MIA.
I still have a mild noise problem in one of my 3501's and I'm trying to pinpoint where it might be coming from. I just realized one of the schematics is MIA.
Thanks rsavas,
That's interesting...
I think I get it now. It looks like in the earlier manuals they split the input preamp apart across two pages and in the later manual (the one posted online) the whole input preamp is combined on Schematic #1. So the later 3501 manual is not actually missing anything they just didn't update the schematic page numbering. They probably should've put a "Schem #2 deleted" note in the manual.
Opto’s and more
Hi, all,
I believe I about a year or two back, I had posted somewhere a few problems with black plastic circular cased opto’s that I had purchased on eBay. Seems the ambient room light affected the readings! Shielding one of these plastic cased opto’s from a single 60 watt overhead bulb, caused marked changes in the resistance readings in a not-in-circuit opto! So tuning the circuits of an Amber 3501/3501A, then replacing the sets cover would totally retune the circuit.
I complained vigorously to the Chinese supplier, but they had no idea what I-was talking about!!! Obviously - due to a defective design, I thought about covering the black plastic body with a copper tape, to shield it, but that still leaves the areas where the leads enter and exit the opto. No really good solution. I guess these Chinese supplied opto’s cannot be used.
Hope that helps someone.
Steven
Hi, all,
I believe I about a year or two back, I had posted somewhere a few problems with black plastic circular cased opto’s that I had purchased on eBay. Seems the ambient room light affected the readings! Shielding one of these plastic cased opto’s from a single 60 watt overhead bulb, caused marked changes in the resistance readings in a not-in-circuit opto! So tuning the circuits of an Amber 3501/3501A, then replacing the sets cover would totally retune the circuit.
I complained vigorously to the Chinese supplier, but they had no idea what I-was talking about!!! Obviously - due to a defective design, I thought about covering the black plastic body with a copper tape, to shield it, but that still leaves the areas where the leads enter and exit the opto. No really good solution. I guess these Chinese supplied opto’s cannot be used.
Hope that helps someone.
Steven
More Amber 3501A thoughts
I also did some measuring on the (100) 22uF./35V tantalum caps I bought, seems about 80 had very good ESR, Capacitance values, and Losses, as noted on my little Chinese tester units, but the last 20 were all over the place, with inferior readings, poor ESR, etc. probably ready to short or to provide poor bypassing... Either these were very old parts or parts that had significant defects and impurities that had made their way into the mix, during manufacturing. So Tantalum caps need to be screened, especially cheaper ones from “not first line” suppliers.
Steven
I also did some measuring on the (100) 22uF./35V tantalum caps I bought, seems about 80 had very good ESR, Capacitance values, and Losses, as noted on my little Chinese tester units, but the last 20 were all over the place, with inferior readings, poor ESR, etc. probably ready to short or to provide poor bypassing... Either these were very old parts or parts that had significant defects and impurities that had made their way into the mix, during manufacturing. So Tantalum caps need to be screened, especially cheaper ones from “not first line” suppliers.
Steven