HP 8050A cal info wanted

[bfish]

I just bought an old, green, Altec-labeled Hewlett Packard 8050A audio analyzer at a univ. surplus auction. Does anyone have any info on the calibration procedure, or have a recommendation for a qualified service center? I'd also be interested in a copy of the manual or other info for it. Couldn't find anything on the HP or BAMA sites.

I've never seen these in any Altec catalogs. Were they made available to Altec contractors? I'd think the production cost of the custom paint and labeling would have been prohibitive for factory-only use.

Speaking of the factory, a recent road trip took me by the old Alt/Univ OKC plant. It was too dark for me to tell what's going on there now, but it's definitely still there. (Something that can't be said for many of the other old Route 66 icons, Kerouac would find little of interest there these days!)

[Todd W. White]

The 8050A was the first real-time 1/3-ocyave analyzer available. It was built for Altec by HP and Altec sold it only to trained Acousta-Voicing contractors.

They were very expensive.

I think I know of a guy that has the literature - email me and I'll send you his contact info.

[maple5438]

Hi
I just noticed there is one of these listed on ebay right now.

http://cgi.ebay.ca/Hewlett-Packard-8...QQcmdZViewItem

[bfish]

Mine's the same, except is a portable, with a flip-down tilt support, instead of rack-mount. Only had to give $45 for it (gotta love those university surplus auctions!). I've been using a software-based RTA (TrueRTA), also one-third octave, which does a great job at home, but the peripherals required (external sound card and mic preamp with ghost power for the calibrated Behringer mic) make it very awkward for portable/remote use with my laptop.

With no manual or recent calibration, and not knowing mic requirement details, I'll put off using my 8550, but if and when I obtain such info, I'd be happy to share it with other members. I'll update this post when that happens.

[Todd W. White]

Bfish -

Did you ever locate the manuals for this unit?

[bfish]

A quick look at the M21 mic sheet semi-confirmed my suspicion, as it ran on 200V.

While looking, I tripped over some lipstick mic trivia I'd never heard before;

(copied) John Hilliard, chief engineer for Altec-Lansing, explained how the name came into being during an interview on NBC's "Hall of Science." He quipped, "Early in its (the M21) development, I used my wife's lipstick case to make an experimental model, and by comparison the size is practically the same."

What a guy!

[bfish]

Nada. All I ever found was a reference in a Shure measurement mic spec sheet that gave the 8050A's phantom voltage at a whopping 130V. Glad I didn't connect any of my mics before I found that out.

"When using the ES615 with the Dukane Model
99A600 Audio Spectrum Analyzer, Communications
Company ARA-412 Acoustic Response Analyzer, or
Altec (H-P) Model 8050A Real Time Audio Analyzer, it
is recommended that a Shure M67 Microphone Mixer
or equivalent device be used as a preamplifier between
the ES615 and the analyzer due to the low input
sensitivity of these units. NOTE: The Altec 8050A microphone
input is at a 130-volt potential for powering
a condenser microphone; using this input it is possible
to permanently damage the ES615. Connect the M67
output to the Altec 8050A direct input through an appropriate
adapter."

Also found;
Operating and Service Manual for the HP 8050A Audio Analyzer
HP Part no 08050-90002

Watched another 8050A go by recently real cheap (<$40).

Found one on the web advertised for >$4300.00...no manual...

Haven't checked the Altec M21 spec yet, wondered if it might be a direct connect without the accompanying PS. Not that I can afford an M21...

I keep checking the Agilent site though, they are continually adding legacy HP stuff. (cross fingers)

Without a schem, I'm hesitant to try to lower the phantom to std levels. So it just gets dustier...

<font color="#FFFFFF" size="1">[ October 28, 2007 01:04 AM: Message edited by: bfish ]</font>

[Earl K]

Brad,

- I have to believe that the Syn-Aud-Com people are going to have the info you seek .
- Don & Carolyn Davis ( founding members of that organization ) and alumni of Altec ( at least Don was ) were pioneers in the development & use of, 1/3 octave RTAs.


- The very model you have is mentioned in their first 2 books / apparently 500, 8050s were sent out into the market.
-FWIW, ( Really this book is a "must-have" for those serious about Sound System Engineering ) .

- Look them up and ask for help / but be fore-warned / you'll likely be taken to task for living in the past and not getting into TEF &/or FFT analyzing ( so get your "story" straight first before calling ) .
- These are very "forward looking" people ( but with the most solid of roots ) .
- Here's the lastest edition ( I have the second edition ) & I'll be buying this lastest, ( as much for Dons' wisdom as for more writings by Dr. E. Patronis jr ) .



- Also, "GoldLine might have this info on hand ( be prepared to pay ) since recently I had to pay ( fairly significant $$$ ) for a schematic of my ( "on the fritz " ) Loftech TS-2 . ( They aren't handing out pdfs for these old pieces ) .



<font color="#FFFFFF" size="1">[ October 29, 2007 09:02 PM: Message edited by: Earl K ]</font>

[Todd W. White]

I've known Don & Carolyn for a long time - I'll e-mail them and ask them about it.

I doubt if Syn-Aud-Con would have it - my guess is that the Davis' do.

Not sure why the new edition doesn't have Carolyn's name on it - she has the BEST set of ears in the business!

[bfish]

Thanks Guys!

I'd considered the possibility of a few "pay-for" options, including those you mentioned as well as Iratech and a couple others, but haven't yet pursued them as my list of projects I've found free service lit for has no end in sight. My interest in the 8050A is purely historical, since TrueRTA blows it away in function. Too much other stuff to fix first that I actually have a use for. While I'd love to have the info, I don't figure it's worth anyone going to signifigant effort for...yet. I figure Old Guy might clean out his attic by the time I get around to needing it.

Once known, I probably can't afford any of the "correct" mics for it anyway.

Oh yeah, I've been 'taken to task' for living in the past so many times it just bounces off now!

Not having any early editions, I do intend to buy the new release of Don and crew's book. Google's preview of the second edition sure left me wanting more!

<font color="#FFFFFF" size="1">[ November 05, 2007 02:42 PM: Message edited by: bfish ]</font>