Hi John: It's my recollection (and so subject to bad memory) that the 3325's claim to fame is that the amplitude is settable in steps of 0.01 dB. Also the amplitude accuracy is very good. Because of this the 3325 is still called out as part of the required test equipment needed to calibrate other test instruments. The A model uses mechanical attenuators that wear out and the B model uses some more reliable attenuation scheme. Once the A model breaks it's toast. Since they are still needed for doing calibrations the demand for the more reliable B model is driving up the price. http://www.tucker.com/images/images_spec/00000015.pdf
Have Fun, Brooke Clarke -- w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml http://www.precisionclock.com John Ackermann N8UR wrote: >I've always been curious about the 3325A vs. B -- there is more price >spread between those two than just about any other HP A vs. B model. >What's the difference between them, and is it worth anything like that >much (obviously, Mike doesn't think so :-) ). > >I've been happy with my A model, though it often fails amplitude >calibration on powerup. Waiting a few seconds and then running the cal >always works, though. > >John >---- > >Mike Feher wrote: > > >>Seems like a lot of money to pay for one. I have been using an HP 3325A for >>about 25 years and like it very much. I bought it brand new from HP for the >>company I worked, where I was director of engineering. After I resigned, to >>pursue greener pastures, they eventually closed down their hardware >>capability and operations and offered me the entire laboratory and inventory >>which then I purchased personally. I would recommend you getting the "A" >>version for about one fifth of the price of that "B" model, unless, you have >>an overwhelming desire to get the "B" for some special reason. Option 001 >>provides the high accuracy ovenized reference and it does not look like the >>one on ebay has that option. Normally they would use a TCXO. Regardless, >>since you will be using an external reference it really does not matter. The >>"A" also accepts an external reference and I run my off of a local Rubidium. >>73 - Mike >> >> > > >_______________________________________________ >time-nuts mailing list >time-nuts@febo.com >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
