Nice one! Looks like it's in good cosmetic condition. These things are really handy for calibration of oscilloscope time bases. I'm surprised there is actually a proper ovenized oscillator in there.
I believe this model was between the 184 (tubes) and TG501 (compact TM500 module). Appears to share some mechanical parts with the TM500 series. It will be interesting to see the insides. Too bad time mark generators are kind of a one trick pony, not much else you can use them for apart from calibrating analog scopes.
I have one of these 2901's - neat units. Ideal for scope calibration. One of the cool features is you can press in just about as many of the marker selector switches as you want at the same time - it will output markerss for all of them.
How long did you let it warm up? I think Tektronix recommended at least an hour and I seem to recall they also recommend leaving it on all the time if possible.
I used to build much larger silver and nickel plated coils for high power RF equipment, so I've seen them both after a few years.
If you're interested you might want to see how Tektronix made the circuit boards back then:
http://www.classictek.org/index.php?option=com_content&view=article&id=185:tektronix-circuit-boards&catid=88:tektronix-videos&Itemid=80
I believe the OCXO was not very accurate. A decent modern day XO will have a similar performance, but you don't exactly need 0.01 ppm performance for calibrating an analog scope.
I don't see any reason to doubt the accuracy based on your results, but an analog scope isn't exactly a hard test for an OCXO. My comment was based on the 20ppm accuracy spec after warm-up, which is close to the performance of a normal XO.
I have one of these too! Thought I was the only one still hanging on to one. They're not needed for digital scope calibration, but they do still have an interesting use. The time marks are essentially impulses, and so are very rich with harmonics. You can use them as a comb generator for RF work.
The time marks are essentially impulses, and so are very rich with harmonics. You can use them as a comb generator for RF work.
I don't have the manual in electronic form. I don't have a scanner, but if there was something specific you needed out of it, I could take a hi-res photo of the page. If you want an entire manual, check this out:
http://www.ebay.com/itm/TEK-2901-TIME-MARK-GENERATOR-SERVICE-AND-OPS-MANUAL-/370221905595?pt=BI_Books_Manuals&hash=item5632f1f6bb
I have some of their CD manuals for other instruments, and they do a really good job.
You can probably get the manual cheaper if you buy it directly from his website. Especially if you opt to download it instead of having a CD shipped. The 2901A not listed on his website for some reason, but you'll probably get a quick response if you send an email. He's a very reliable source and has a good reputation within the Tek/HP repair communities.
The time marks are essentially impulses, and so are very rich with harmonics. You can use them as a comb generator for RF work.The OCXO reference may actually be important for this application.
The time marks are essentially impulses, and so are very rich with harmonics. You can use them as a comb generator for RF work.The OCXO reference may actually be important for this application.Gents, mind explain what is this all about ?
If you're interested you might want to see how Tektronix made the circuit boards back then:
http://www.classictek.org/index.php?option=com_content&view=article&id=185:tektronix-circuit-boards&catid=88:tektronix-videos&Itemid=80
Please note that nobody, in the board fabrication plants, wears gloves or eye protections or masks: workplace safety was less important, in those days.
Nice one! Looks like it's in good cosmetic condition. These things are really handy for calibration of oscilloscope time bases. I'm surprised there is actually a proper ovenized oscillator in there.
Thanks, yeah, external condition is still very well preserved as you can see, thats one of the reason I grabbed it, quite a gamble though without knowing how it looks like inside.
I was also quite surprised its still working very well, did a brief 15 minutes test with my frequency counter showed the decades old ovenized 10 Mhz oscillator inside is still at pretty good accuracy, will post the result once I opened it up.I believe this model was between the 184 (tubes) and TG501 (compact TM500 module). Appears to share some mechanical parts with the TM500 series. It will be interesting to see the insides. Too bad time mark generators are kind of a one trick pony, not much else you can use them for apart from calibrating analog scopes.
Actually it was kinda impulse buy even I knew it does only that.
Stay tuned, definitely will post it's internal parts shots here.