Attention Heath TT-1 Tube Tester owners

Please consider scanning it instead, make a PDF (or just a tarball of the images) and post it to the files section in the Heathkit Yahoo group, or provide an url for download instead. This would help a lot of folks down the road. There are a number of scans of versions of this data, but yours may be more inclusive or of better visual quality.

Michael

this does bring up an interesting thought, not totally unrelated - with today's inexpensive computer interfaces, why not build/market a tube tester accessory that would plug into a USB bus - all you would need is one of each kind of socket on the unit, and a couple of power sources (filament and plate/bias voltages) - so a set of SCRs to choose filament voltage and apply it to the proper pins, 4 or four cheap D/As to create the voltages (maybe with an HV op amp to create higher voltages), and op amps and A/D with a mux to scan voltages and currents on all the pins of every socket - this would probably take no more than 50 to 100 parts and a small PC board and you could have the tube info read from a computer database and have the test results displayed graphically - transconductance plots, leakage, emissivity, all those esoteric parameters.

Done as a labor of love, where the NRE is not amortized, it could be profitable at the $150 to $300 price range - wouldn't this be a good thing? it would take less space, be more accurate, faster and less error prone than using a 40 to 60 year old largely mechanical device.

so, who's gonna make it?

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an

Hunh, it should be so simple! I suppose a wide range switching supply for the filaments would work, but it needs to be able to supply between 1V@50mA and 120V@100mA as well as up to 3-4A at around 6V. Likewise you would need 3 variable DC supplies for plate, screen and grid bias as well a source of AC signal for the gm measurements. Also some form of 'free-point' switching to connect the various sources and measure inputs to the socket pins [at up to 4A and 500V]. Then you need the detectors as you say. Methinks the parts cost would be a bit above your estimate. Then the program to run all that stuff and display the results and, finally, creating the tube test data tables. Sounds like a couple of man years work.

I am in the process of adapting a Heath IT-3121 output to test tubes, and that simply needs a bias amplifier to drive the control grid, an external supply for the screen and a filament supply. It looks like the IT-3121, an IP-17 and a socket box will do the job along with the bias amp. That's only about a week's work.

Neil S.

Already available here:

I was thinking that I'd seen it at SND Tube Sales, but looking right now, I don't see it.

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Jim, if you live in a medium sized city chances are you have a company that copies architectural drawings. These guys have continuous feed photocopiers that will copy almost ANY length of paper! Not saying it will be cheap though, but perhaps if you provide the roll of paper it might go easier on you? Here in Vancouver a company called TR Trades has a few of these machines going all day long and they ar every handy for making long copies of my schematics, plus they can reduce or scan them as well. However they are in business and do not do this for free.

I have heard that these endless length copiers turn up on eBay from time to time, perhaps someone here has one?

John :-#)#

Interesting thought. I didn't know that such things existed. I can ask around. It's likely that if I had more than one made at the same time, each one might be cheaper.

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Yep. They do. The only downside is that you are stuck with whatever default width the machine takes. We keep one in the office that is set for 42" as the standard width. Lots of waste for small drawings. It is "scanner-to-plotter" HP technology and so does color (very nicely) as well. NOT CHEAP. It also operates (with different dyes and/or inks) on vinyl, finished fabrics, sticky-back or slick paper - even more expensive.

On the other hand, as the entire system is computerized, we often will print-in-parallel so as not to waste paper. We can scan one 18" banner into the system and print two out on the 42" stock with good margins. If you are using 8.5 x whatever originals, you could print four rows in parallel. All this can be set up after the initial scan and before the *expensive* "PRINT" button is hit. 11 x 17 fold-outs can also be accomodated in the initial set-up without (much) waste.

As William notes below, the length that can be plotted/printed is limited only by the length of the printer-stock roll.

Peter Wieck Melrose Park, PA

Hmmm, we have a 36" roll-fed plotter. I wonder if I could reformat all this into the right width and then print out 4 (or whatever) of them at a time. To do this right, I think I'd have to pull all this data into a spread sheet first, so I could format the info into the right usable shape.

The interesting part would be to design a cutter to cut them into strips as they come out of the plotter....

It's still worth checking at our local print shop to see what they can do.

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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The Full Adobe Acrobat program will Scan an existing Roll Chart from a tube tester. Only problem with it would be page ends margins and such that you wouldn't want margins at the end of each sheet to make new roll charts up. Could be an interesting project.

John k9uwa

Many such printers / plotters include cutters for separating the output of different prints / plots.

Interesting thread... I use a Heathkitt TC-2 quite a lot - the chart is in good shape (still !), but I'm not convinced that rolling it up and down is the best way to get to specific tube set-up data (of course, it's always to hand... er, thumb !) For odd-balls, you have to go to the supplementary sheets anyway. It's cheaper to copy it sequentially onto separate 8 1/2 x 11 sheets (two sided, one or two columns, use a paper mask on the "other" column as you don't want it on the same page), spiral bind them and keep them with the tester. I've done this for the Heathkit tube supplementary sheets (and for most downloaded manuals.) Then simply scan down to the tube you want by eye. Easy to add extras, too. I don't say scrap the roller chart - put it back carefully for posterity (repaired as needed) and keep it there, but not used much. Cheers, Roger