Film-Tech Forum ARCHIVE: osciloscope & rta´s

This is topic osciloscope & rta´s in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Mike Moreno (Member # 4887) on 09-28-2009, 02:12 PM:

i hace to travel for diferent cities carrying my BIG..osciloscope and rta.
can someone recomend me a small equipment that maybe can plug to my lap top to make the trip easer?
y read about usb equipment but i really don´t know wich one is good.
thanks
mike moreno
mexico

Posted by Mike Babb (Member # 1379) on 09-28-2009, 08:48 PM:

http://www.acoustx.us/Products.html#completesystem

Posted by Mark Gulbrandsen (Member # 72) on 09-29-2009, 06:52 AM:

I don't think there are many if any really good USB scopes available. I still reccomend a Tektronix either the 465B or the later 2465 which is quite a bit lighter. I recently converted to the 2465 because it is not so heavy and I was able to aquire a really nice one for about a hundred dollars. The downside of the 24XX series is the lack of available replacement IC's as Tektronix had all of them custom made. All of the sweep amplifiers and power deflection stages are monolithic ICs and the horizontal sweep IC is extremely prone to failure. You more or less have to keep a parts unit around to be able to keep these models running for the long term. On the other hand if you don't mind it's weight the 465B is still the most durable and reliable scope ever produced by anyone.

I second Mikes suggestion on sound analyzers.

Mark

Posted by Monte L Fullmer (Member # 2797) on 09-30-2009, 09:09 PM:

Nope, can't complain about the 465B - love mine...

-Monte

Posted by John Walsh (Member # 168) on 10-01-2009, 01:22 PM:

I can second Mark's suggestion, and experience, regarding the Tektronix 2465 series having recently gone through it ... good scope, but parts are scarce.

Posted by Randy Stankey (Member # 64) on 10-02-2009, 01:25 PM:

+1 on the 465B! [thumbsup]

I got one at Mark's suggestion. Good piece of equipment.
Size and weight are secondary.

Posted by John Hawkinson (Member # 1135) on 10-02-2009, 04:12 PM:

Raise your hand if you have a rackmount oscilloscope in your booth [or a waveform monitor]?

(No, we don't. I've been tempted, but the rack space is just too dear...)

--jhawk

Posted by Steve Guttag (Member # 268) on 10-02-2009, 04:39 PM:

Well...in the AFI/Silver, yes, they have a vectorscope and waveform monitor. No RTAs though.

Steve

Posted by Mark Gulbrandsen (Member # 72) on 10-02-2009, 11:58 PM:

I have two Videotek TMV-621 wvfm/vector scope combos. By far the best scopes of their type I've used. Tektronix may have a better one but at probably 6 times the price.

I settled on Videotek for my repair bench because they are well made., parts are easy to get(they are owned by Harris), the crts use P-4 phosphor and have a white trace that IMHO is alot easier on the eyes and they are more flexible than Tektronix in the same price range. I am sending my Tektronix Wfm and vector scopes to another Film-Techer.

Mark

Posted by Randy Stankey (Member # 64) on 10-03-2009, 12:27 AM:

quote: John Hawkinson
Raise your hand if you have a rackmount oscilloscope in your booth [or a waveform monitor]?

Thought about it for a while but I took a couple of aspirin and laid down for a while until the feeling went away. [Wink]

Like you, rack space is short.

Posted by Mark Gulbrandsen (Member # 72) on 10-03-2009, 10:39 AM:

The combination monitors like the TVM-621 and TVM-675 are for those that don't have alot of space!!!b They monitor audio as well. Similar versions are made for digital video.

Mark

Posted by Steve Guttag (Member # 268) on 10-03-2009, 12:28 PM:

Keeping with the Videotek/Harris theme and economizing on rackspace...check out their 1U (plus conventional monitor) solution...I've seen them in action and they are way cool.

http://www.broadcast.harris.com/products/test/vtm.asp

Steve

Posted by Mark Gulbrandsen (Member # 72) on 10-03-2009, 12:43 PM:

Yep, those things are all over the place on Farnsworth Peak, mainly located in the transmitter equipment support racks. The convenience is there because it can display all pertinent info on the same screen at once. However, it doesn't REALLY save on room because you still need some sort of composite or VGA monitor to display on and that also normally goes in the rack. You could use an on line monitor and switch back and forth but then it becomes inconvenient. Tektronix has had similar units for as long as Videotek. I miessed a Tektronix unit on E-bay for a BIN of just $120.00!

Mark

Posted by Steve Guttag (Member # 268) on 10-03-2009, 06:40 PM:

Generally, there is a VGA monitor somewhere in the workspace already anyway...and hence the space saving. You can also home in on the specific function of interest and really get some precise readings or leave it in the general mode of showing smaller versions of everything.

Steve

Posted by John Hawkinson (Member # 1135) on 10-03-2009, 08:22 PM:

So are these things decent enough do do an A chain on?

--jhawk

Posted by Mark Gulbrandsen (Member # 72) on 10-03-2009, 08:42 PM:

John,

Not really intended for that. Although they can monitor audio they are not a dual sweep scope in the literal sense. These scopes include an X-Y input and some models have an AES input strictly a monitoring device.

Mark

Posted by Paul J. Neuhaus (Member # 3205) on 10-08-2009, 01:56 PM:

a pretty good scope that I have used with usb screen capture capabilities is the Fluke 199C handheld

Posted by Mark Gulbrandsen (Member # 72) on 10-09-2009, 07:27 AM:

Paul,

Hand held scopes are great for many things however the problem with that type of scope is that you can't look at the Dolby Digital video waveform with it. It does not have a fast enough sampling and refresh rate to do the job.

Mark

Posted by Marco Giustini (Member # 4544) on 10-09-2009, 05:27 PM:

I love my Fluke 3082. Definitely not small but there aren't any trimmers inside: fully digital controlled, but old-fashioned CRT!

Posted by Mike Moreno (Member # 4887) on 10-20-2009, 02:48 PM:

and what can you tell me about a decent real time analizer?

Posted by Steve Guttag (Member # 268) on 10-20-2009, 05:59 PM:

There are many "decent" ones. That is, there are many that will give good displays and potentially very useful information. Smaart Live http://www.eaw.com/products/software/EAWSmaart/ Is quite popular in the A/V and Pro audio circles (Dolby even had/has a version of it but oriented towards cinemas). However, who is doing the mic calibrations? When you get a plexer (such as the USL)...who is "calibrating" them in either frequency or level? The quality of the reading is not determined so much by the display but by the signal being displayed. Part of what you are seeing when you look at a typical analyzer is the frequency response of the microphone superimposed over the frequency of the sound you are measuring.

However, the D2 analyzer gets the highest marks in my book (for what it measures) because it is the only one that really has a combination of mic normalization as well as a means for uniform calibration. If you have your mics calibrated each year (a requirement for any meaningful analyzer) then you are going to get VERY consistent results out of the D2.

As such you can have several different techs use either an R2 or D2 and despite differences in techniques or exact mic placements, achieve nearly identical results.

http://www.acoustx.us/index.html

Steve