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HP Forum Archive 08

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Value of HP 200A audio oscillator??
Message #1 Posted by jake wimberley on 29 Apr 2002, 10:06 p.m.

Hello... I am a student in EE at Mississippi State, and a licensed radio amateur. Here on campus we have a ham radio club, which we are in the process of rebuilding after three years of downtime. The other day we were moving all of our equipment, along with lots of antique radio and test gear, from storage to our new station. I found an old HP 200A oscillator [HP's very first product] in good condition, at least cosmetically...I didn't test it to see if it worked. We are hoping to sell all the old stuff and use the money to buy some solid-state equipment to use instead. I told everyone I would try to see how much the HP 200A was worth... I figured it might be somewhat valuable, at least to an HP fanatic. If anybody has any idea how much it might be worth, please email me at: jcw141@msstate.edu.

Thanks, Jake Wimberley, K4ZAU

      
Re: Value of HP 200A audio oscillator??
Message #2 Posted by Andreas Stockburger (Germany) on 30 Apr 2002, 4:45 a.m.,
in response to message #1 by jake wimberley

Hi,

Perhaps this helps ...

http://www.vaxxine.com/phil/scopes/HP$.htm

Andreas

      
Re: Value of HP 200A audio oscillator??
Message #3 Posted by Ren on 30 Apr 2002, 9:32 a.m.,
in response to message #1 by jake wimberley

Can I have it?

Can I? huh?

Oh, please, Please, PLEASE give it to me! I'll take real good care of it. I'll clean it up, I'll test the capacitors and tubes and get it working just like new. Then I'll convince my wife that it BELONGS on the mantlepiece, and I'll dust it every week and polish its knobs. I'll even pay for packing and shipping! (and shrink wrap- don't forget the shrink wrap B^)

Seriously, I'd be interested, but I probably couldn't afford it. Do a web search for "boatanchors", that is what affecionados of tube type equipment call their passion. There is also a newsgroup to ask on. I _think_ it is called rec.antiques.radio+phono just check the antique newsgroups for the proper spelling. There may also be a boatanchors newsgroup under the rec.radio.* hierarchy, oh yeah, you're in a ham radio club, so I assume you've already asked on those newsgroups?

      
Re: Value of HP 200A audio oscillator??
Message #4 Posted by Ellis Easley on 30 Apr 2002, 9:34 a.m.,
in response to message #1 by jake wimberley

I was interested in one on Ebay several years ago that had been modified - an additional control had been added to the front panel. It was listed as an antique and sold for about $150. I would try to play up the "end of an era" angle - maybe get a testimonial from one of the family heirs - and have a high reserve price, relisting as many times as necessary to find AT LEAST TWO sentimental old fools (or young ones). Find an image of the college thesis that its design is based on to include in the auction listing. Throw in a copy of the movie "Fantasia" since it is part of the legend.

      
update on 200A
Message #5 Posted by jake wimberley on 1 May 2002, 11:54 p.m.,
in response to message #1 by jake wimberley

I was at the station again today, and realized it's actually a 200C, not a 200A, although it seems to be the same product. My bad. I would assume this makes it somewhat less valuable.

Thanks, Jake K4ZAU

            
Re: update on 200A
Message #6 Posted by Ren on 2 May 2002, 1:21 p.m.,
in response to message #5 by jake wimberley

I own an HP-200C (or D), and I saw a photo of the 200A in an article in Electronics Now a few years back. The 200A had square corners and was about twice the front panel area of my "newer" model. I bought mine for $35, though I've seen $100 asked. I donated one of my older HP signal generators (a sister model to the one I have now, but with a slightly different frequency range) to a grade school about 3 years ago. (So they could hook a speaker to it and make siren sounds).

            
Re: update on 200A
Message #7 Posted by Ellis Easley on 3 May 2002, 2:49 p.m.,
in response to message #5 by jake wimberley

The 200A has the controls on the broader side of the cabinet with the big frequency dial in the middle and the range and output level controls on either side. I'm familiar with the 200CD which is the model that was in production till the 80's and a similar model 201C which had a narrower frequency range (20 Hz - 20 kHz in three ranges vs. 5 Hz - 600 kHz in 5 ranges for the 200CD), better frequency accuracy (I guess because the dial only covers 10X vs. 12X), less hum, more power output and a better output attenuator. Both of these have the controls on the smaller side of the cabinet with the big frequency dial on top and the range and output level controls below. Which of these styles describes your 200C?

There is a picture of an HP-200A in "Analog Circuit Design", edited by Jim Williams of Linear Technology. It is on page 44 in an article by Williams about how he tried to improve the design with modern semiconductors on a rainy day. The article also has excerpts of William Hewlett's 1939 Stanford thesis. This is a great book for anyone interested in electronics. It's not a textbook but a collection of articles by people who have worked in a number of areas of electronics design. One of my favorites is by Bob Pease of National Semiconductor, who started out at Philbrick, he explains why nobody was able to copy the Philbrick P2 operational amplifier module successfully. Pease has his own great book, "Troubleshooting Analog Circuits". Both books are published by EDN.

I saw a 200CD in a scene in a recent TV series, "Total Recall 2070". It was in a makeshift lab where the ultimate android was developed, presumable around the year 2070. I believe these oscillators will still be working then! (only the leather handles will have disintegrated)

                  
Re: update on 200A (HP Audio Signal Generator)
Message #8 Posted by Ren on 3 May 2002, 3:26 p.m.,
in response to message #7 by Ellis Easley

Ellis, it has been a couple years (or more) since I fired up my HP Signal Generator, so I'm not sure of the Model Number. Going by your definition, I have the 200CD, it was a 200C that I donated to a grade school. I was moving at the time and had to cut back on some of my "stuff". I paid $35 each for both at a college auction. Thanks for correcting me. Now what was the even smaller solid state model? 201CD?

                        
Re: update on 200A (HP Audio Signal Generator)
Message #9 Posted by Ellis Easley on 3 May 2002, 4:56 p.m.,
in response to message #8 by Ren

I had spent some time writing one of my exhaustive treatises in respose to you, then after previewing it and seeing a error, I hit the back button and all my work had dissapeared! I quickly hit the forward button and Windows or IE or someone informed me that the page had expired! Probably did us all a big favor! Short answer - I think you mean the 204C or the 204D or the 209A, these are all small, solid state, and the same size and style as the 403B AC voltmeter, apparently HP frequently sold them in pairs.

I should have remembered to copy the text I had written in case what happened, happened, since it has happened before.


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