Hi JWB,
The 2465 is actually a really nice scope, and very wide bandwidth!! All that P to P wiring was the norm back then, but TEK was all first class no matter what. TEK introduced PCB's in the early 60's and only on one model, the 321. The 321 was also their first solid state scope and was battery operable. They went back to P to P after that model and didn't use pcb's again for quite a few years.
The neat ceramic strips have silver inlays and you HAVE TO use silver solder on them or the silver may lift off the ceramic.
There is a forum for Tektronix scopes with over 600 members at Yahoo and many web sites dedicated to the older Tektronix tube oscilloscopes. Several of them contained close to 100 vacuum tubes! Musta taken a month to test em all.
Mark
The 2465 is actually a really nice scope, and very wide bandwidth!! All that P to P wiring was the norm back then, but TEK was all first class no matter what. TEK introduced PCB's in the early 60's and only on one model, the 321. The 321 was also their first solid state scope and was battery operable. They went back to P to P after that model and didn't use pcb's again for quite a few years.
The neat ceramic strips have silver inlays and you HAVE TO use silver solder on them or the silver may lift off the ceramic.
There is a forum for Tektronix scopes with over 600 members at Yahoo and many web sites dedicated to the older Tektronix tube oscilloscopes. Several of them contained close to 100 vacuum tubes! Musta taken a month to test em all.
Mark
Right, which is why I was hoping to have a nice FET differential probe to go with it, but without paying $1500+. Which brings me back to the matter of d-i-y FET probes.
<a href="http://www.linear.com/pdf/an70.pdf">Linear AN70</a> has two nice sections on building your own probes for picking up radiated energy.
Bricolo,
There are quite a few good reasons to build an oscilloscope - but saving money isn't one of them. DIY oscilloscopes like the Bitscope are interesting because of the PC interface, sampling capabilities, and customizable design available at affordable prices.
However, for everyday use, a good quality used analog scope can be quite a bit less expensive and will usually serve all of your audio oscilloscope needs for some time. Now is a good time to look for an oscilloscope, as most companies are ridding themselves of analog scopes in favor of digital - this leaves a large surplus of excellent analog scopes at essentially give-away prices.
As an example, I picked up a 100MHz Tek scope recently for $30USD at a local hamfest - dual channel, delaying dual time base, calibrated three years ago. The seller was from a telecom company, making some space in a storage warehouse. eBay was useful for once, to complete the scope with a pair of 200MHz Tek probes, for $26USD.
Try to find amateur radio clubs locally - they'll know the most about upcoming hamfests and excellent sources for components in general. eBay was once a great source for bargains, but these days it's a storefront for people making a living buying from estate sales and self-storage auctions and reselling at rather inflated prices. Oscilloscopes in particular are completely overpriced up to the 100MHz level. Hamfests are also much more enjoyable than hunting through pages of meaningless eBay descriptions - "Powered up, don't know how else to test - great condition, perfect for a beginner!!!", etc, etc.
Specific recommendations - try to pick up a Tektronix scope. The build quality of the scopes built in the 60's and 70's is far higher than most other scopes ever built (including quite a bit of Tek's current crop). Spare parts and internet support are also far more available. Another advantage is that you can often get away with a lower sticker bandwidth rating on a Tek scope and still capture signals that you may not be able to with other scopes - for example, a Tek 100MHz scope can trigger on 200MHz signals in some cases. The signal will be quite attenuated and not at all within calibration, but if you just need to see the signal (most cases), it'll usually show up.
The Tek 465 is a portable, 100MHz scope recommended by many. If you don't need a very portable scope, look around for a 7000 series Tektronix. These scopes are a solid state modular design, composed of a mainframe with slots for three to four plugins to define the scope's capabilities - available up to 1GHz bandwidth.
For example, a Tek 7603 mainframe is highly available and rated for 100MHz. Add a vertical amplifier plugin and a timebase and you have a basic scope. Add a second dual channel vertical amp and you have a four channel scope. With a four bay mainframe, you can also add a second time base for a four trace scope with a timebase for each pair with delay. Pull out the timebase and plug in the second vertical amp and you have an excellent, calibrated X-Y scope. Plug in a sampling unit and view waveforms up to 1GHz. Some of the other interesting plugins available include a curve tracer, 225/525MHz frequency counter, and 1.8GHz spectrum analyzer. Highly versatile system, and inexpensive - the scope I picked up is a 7603 with a 7A26 vertical amp and a 7B53A timebase. Quite a bargain.
Hope this helps other scope-seekers on a hobby budget...
-Nikhil
There are quite a few good reasons to build an oscilloscope - but saving money isn't one of them. DIY oscilloscopes like the Bitscope are interesting because of the PC interface, sampling capabilities, and customizable design available at affordable prices.
However, for everyday use, a good quality used analog scope can be quite a bit less expensive and will usually serve all of your audio oscilloscope needs for some time. Now is a good time to look for an oscilloscope, as most companies are ridding themselves of analog scopes in favor of digital - this leaves a large surplus of excellent analog scopes at essentially give-away prices.
As an example, I picked up a 100MHz Tek scope recently for $30USD at a local hamfest - dual channel, delaying dual time base, calibrated three years ago. The seller was from a telecom company, making some space in a storage warehouse. eBay was useful for once, to complete the scope with a pair of 200MHz Tek probes, for $26USD.
Try to find amateur radio clubs locally - they'll know the most about upcoming hamfests and excellent sources for components in general. eBay was once a great source for bargains, but these days it's a storefront for people making a living buying from estate sales and self-storage auctions and reselling at rather inflated prices. Oscilloscopes in particular are completely overpriced up to the 100MHz level. Hamfests are also much more enjoyable than hunting through pages of meaningless eBay descriptions - "Powered up, don't know how else to test - great condition, perfect for a beginner!!!", etc, etc.
Specific recommendations - try to pick up a Tektronix scope. The build quality of the scopes built in the 60's and 70's is far higher than most other scopes ever built (including quite a bit of Tek's current crop). Spare parts and internet support are also far more available. Another advantage is that you can often get away with a lower sticker bandwidth rating on a Tek scope and still capture signals that you may not be able to with other scopes - for example, a Tek 100MHz scope can trigger on 200MHz signals in some cases. The signal will be quite attenuated and not at all within calibration, but if you just need to see the signal (most cases), it'll usually show up.
The Tek 465 is a portable, 100MHz scope recommended by many. If you don't need a very portable scope, look around for a 7000 series Tektronix. These scopes are a solid state modular design, composed of a mainframe with slots for three to four plugins to define the scope's capabilities - available up to 1GHz bandwidth.
For example, a Tek 7603 mainframe is highly available and rated for 100MHz. Add a vertical amplifier plugin and a timebase and you have a basic scope. Add a second dual channel vertical amp and you have a four channel scope. With a four bay mainframe, you can also add a second time base for a four trace scope with a timebase for each pair with delay. Pull out the timebase and plug in the second vertical amp and you have an excellent, calibrated X-Y scope. Plug in a sampling unit and view waveforms up to 1GHz. Some of the other interesting plugins available include a curve tracer, 225/525MHz frequency counter, and 1.8GHz spectrum analyzer. Highly versatile system, and inexpensive - the scope I picked up is a 7603 with a 7A26 vertical amp and a 7B53A timebase. Quite a bargain.
Hope this helps other scope-seekers on a hobby budget...
-Nikhil
Re: Re: Digital scopes..
At twice the sampling frequency the only thing you can really say about a waveform is it's frequency. To be able to see what the waveform looks like requires much higher sampling rates.
Don't forget that any deviation from a perfect sin wave indicates the presence of higher frequency components in the signal. If your scope doesn't have the bandwidth and sample rates required, then all you will see is a pretty sin wave fiction rather than what is really going on.
It is amazing how textbook perfect a 10 Mhz clock signal can look when I engage the 20 Mhz bandwidth limit switch on my Tek TDS420. Switch it back to 150 Mhz and ringing and ground bounce along with the odd reflection or two suddenly appear.
When you look at waveforms beyond an analog scopes limits there is usually some visual indication in the trace that there is more going on. Digital Scopes are more unforgiving. If you don't have the sampling rate required to deal with a waveform then a digital scope will lie and just put up what it thinks is the waveform.
Phil
Bricolo said:
At twice the sampling frequency the only thing you can really say about a waveform is it's frequency. To be able to see what the waveform looks like requires much higher sampling rates.
Don't forget that any deviation from a perfect sin wave indicates the presence of higher frequency components in the signal. If your scope doesn't have the bandwidth and sample rates required, then all you will see is a pretty sin wave fiction rather than what is really going on.
It is amazing how textbook perfect a 10 Mhz clock signal can look when I engage the 20 Mhz bandwidth limit switch on my Tek TDS420. Switch it back to 150 Mhz and ringing and ground bounce along with the odd reflection or two suddenly appear.
When you look at waveforms beyond an analog scopes limits there is usually some visual indication in the trace that there is more going on. Digital Scopes are more unforgiving. If you don't have the sampling rate required to deal with a waveform then a digital scope will lie and just put up what it thinks is the waveform.
Phil
Note the discoloration on the ceramic
I note this on the 3XX series scope.
this can (must) be cleaned -- and if you don't clean it it will arc over -- I had this problem with my TEK 545 -- DO NOT CLEAN WITH AN ABRASIVE CLEANER. this will scratch the ceramic surface. I think that I used MEK to clean it up (it was about 20 years ago), but check on the TEK group or at the newsgroup rec.radio.amateur.homebrew for suggestions.
The 2445, etc. are the ne plus ultra of analog scopes.
I note this on the 3XX series scope.
this can (must) be cleaned -- and if you don't clean it it will arc over -- I had this problem with my TEK 545 -- DO NOT CLEAN WITH AN ABRASIVE CLEANER. this will scratch the ceramic surface. I think that I used MEK to clean it up (it was about 20 years ago), but check on the TEK group or at the newsgroup rec.radio.amateur.homebrew for suggestions.
The 2445, etc. are the ne plus ultra of analog scopes.
The 315 has been completely cleaned up. I also rebuilt the high voltage section after that picture was taken. All new caps...high voltage and others. There was a bit of dust/dirt on the ceramic strips in the high voltage section, but there was far more attracted dust around the focus and intensity controls.
The best way to clean these old tek scopes is to put then in your bath tub and use a hand held shower nozzel and soft toothbrush to get rid of the dirt. Dry it out in your oven at 100 degrees for 8 or 10 hours. Then apply Caig De-Oxide to all the switches and contacts, as well as the pots if needed...but most of those are sealed anyway. The scopes end up looking like new. I was taught this by a friend that worked at Sta-Bro Calibration facilities here in Salt Lake City. They have cleaned hundreds of scopes that way to ready them for calibration. I was also told that Tektronix used to dunk the entire instrument in a giant ultrasonic cleaner filled with distilled water.....a bit fancier but basically ending up with the same results.
REGARDING USE OF DIGITAL SCOPES...
There are some audio waveforms that digital scopes cannot display. These include tone bursts that are 180 degrees out of phase, and a number of others. At one place I worked they got me a nice TEK TDS series portable scope...the type with the LCD screen. I use a special Dolby tone burst test film as part of aligning theatre projector soundhead pickups and the scope would not display this simple dual trace signal properly. I enquired with other theatre sound techs and found out it was an inherent problem with those types of scopes.....just thought I'd pass this info along.
Mark
The best way to clean these old tek scopes is to put then in your bath tub and use a hand held shower nozzel and soft toothbrush to get rid of the dirt. Dry it out in your oven at 100 degrees for 8 or 10 hours. Then apply Caig De-Oxide to all the switches and contacts, as well as the pots if needed...but most of those are sealed anyway. The scopes end up looking like new. I was taught this by a friend that worked at Sta-Bro Calibration facilities here in Salt Lake City. They have cleaned hundreds of scopes that way to ready them for calibration. I was also told that Tektronix used to dunk the entire instrument in a giant ultrasonic cleaner filled with distilled water.....a bit fancier but basically ending up with the same results.
REGARDING USE OF DIGITAL SCOPES...
There are some audio waveforms that digital scopes cannot display. These include tone bursts that are 180 degrees out of phase, and a number of others. At one place I worked they got me a nice TEK TDS series portable scope...the type with the LCD screen. I use a special Dolby tone burst test film as part of aligning theatre projector soundhead pickups and the scope would not display this simple dual trace signal properly. I enquired with other theatre sound techs and found out it was an inherent problem with those types of scopes.....just thought I'd pass this info along.
Mark
Here's a really good deal to get someone started with one of the best scopes ever made!!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2523159845
Have fun bidding!
MArk
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2523159845
Have fun bidding!
MArk
Mark A. Gulbrandsen said:
I just bought a 465b myself I am very happy with it. Although I subscribe to the philosophy "if it ain't broke don'tfix it" I was wondering if you have any suggestion on things I should look for when things go bad. For ex.: what is the tell-tell sign that caps are going bad? I have seen a few caps that could easily be replaced like a non polar electrolytic on the bottom board, all the ps el.ytic caps, there is a little bit of play in the time setting knob.
I would like to do a calibration but I don't know the first thing about it.
I love the look of the 315, allen-bradley sealed pots (they work great (I used them in all my preamp projects up until two years ago), perfect point to point layout, I miss that "the right stuff", cold war perfectionism so typical of old american products, all the military connectors, potted transformers...I am digressing...
While I don't have tons of experioence repairing test gear it has been a side interest of mine for years and I've been fortunate to be able to repair/restore quite a few scopes, counters, meters, etc. And I've been able to pick the minds of friends that have worked professionally in the calibation field and read the service manuals. Thats basically how I've learned what I know about it. The best way to learn is by doing it, there is no school other than your own for this field!!
The first thing you will definately need is the service manual. That can be expensive, but watch E-Bay for them. In a bind once I was forced to pay just over 100.00 for a 465 manual!! Had to have it......
First off, never but never adjust any of the B+ or B -, or High voltage adjustments ever. That will in itself throw the scope way out of calibration. You can certainly measure these test points after a 1 hour warm up period and note the readings and then set them back to that exact setting as long as you made no other changes to anything. Things will be pretty close to spec if you note those voltages first.
Things that can be replaced are:
In Tektronix Tube scopes....All the bypass capacitors that have the color coding on them. These are the main cause of non-working Tektronix tube scopes and they are notorious for developing leakage and failing. Use Sprague Orange drops in there to replace them. Next would be electrolytics...but even in the 315 as old as it is, the electrolytics are fine. Here TEK was really smart and used dual 40 mfd sections in parallel so that if one opens up the scope keeps on going and going. Better even than the Ever Ready Bunny can! If electrolytics are found to be bad they should be replaced with similar, or same type...but sometimes they are no longer available. There are several people, and surplus houses, that specialize in old tektronix parts. Try them first. If they don't have them available either empty out the contents of the FP can and install new caps inside of it, or install something thats going to be as rugged as the rest of the scope itself. A simple test is to turn the vert gain all the way up and with the input shorted see at around 60 to 120 hz equivelent sweep speed if there is any hum visible in the waveform. You can also check the ripple with another scope too. If ripple's high replace the caps.
With the case of tube scopes many of them need vert amp tubes with as close to zero heater to cathode leakage as possible. Some scopes HAVE TO HAVE tubes with zero leakage no matter what or there will be hum visible in the trace as I mentioned above. If you purchase a classic tube scope this may be all that is wrong with it.
Solid State Scopes:
In solid state scopes the main thing thats seems to fail are power supply electrolytics, The black square Allen bradley mod pot potentiometers, and then selector switches. The 465B sweep switch may seem a bit loose on some scopes and its not really a rotary selector switch per say, but a plastic drum with indents that press against switch contacts soldered to the pcb. Theyn get turned on and off in different combinations. Be very careful with these contacts and clean only with pure alcohol...nothing else is needed nor will work safely and maintain specs. If it still does not function after cleaning then the contacts are shot and will have to be replaced. A good place to get parts for solid state TEK scopes is from Sphere Research in Canada. They have tons of NOS, used parts, and crt's. The 465 sweep switch is a bit tricky to work on and requires removal of the trigger board to be able to remove the sweep pcb. MAKE DIAGRAMS YOURSELF AS TO WHICH WIRE PLUGS IN WHERE BEFORE TAKING ANYTHING APART!!!!!!!
Keep them clean, especially in the high voltage section and by the intensity and focus pots. If things get dirty around there its possible things may fail as was mentioned in another post in this thread. ABOVE ALL IF THERE IS A FAN, IT MUST RUN!!!!!!!!! SEVERE DAMAGE TO ANY SCOPE WILL RESULT IF ITS FAN IS NOT RUNNING!!!!!!!!
Calibration is another thing all together. One can purchase used calibration equipment if he has alot of scopes to maintain, or of one can get the required equipment cheap. Otherwise repair the scope yourself and then spend the $$ and have it calibrated...if thats really important to you. Many calibration facilities are familiar with your equipment, even if it is really old. many times they can also get resultant specs out of them that way exceed the manufacturers specs, so a good calibration is simetimes well worth the price paid. Hope some of this helps out.
Mark
The first thing you will definately need is the service manual. That can be expensive, but watch E-Bay for them. In a bind once I was forced to pay just over 100.00 for a 465 manual!! Had to have it......
First off, never but never adjust any of the B+ or B -, or High voltage adjustments ever. That will in itself throw the scope way out of calibration. You can certainly measure these test points after a 1 hour warm up period and note the readings and then set them back to that exact setting as long as you made no other changes to anything. Things will be pretty close to spec if you note those voltages first.
Things that can be replaced are:
In Tektronix Tube scopes....All the bypass capacitors that have the color coding on them. These are the main cause of non-working Tektronix tube scopes and they are notorious for developing leakage and failing. Use Sprague Orange drops in there to replace them. Next would be electrolytics...but even in the 315 as old as it is, the electrolytics are fine. Here TEK was really smart and used dual 40 mfd sections in parallel so that if one opens up the scope keeps on going and going. Better even than the Ever Ready Bunny can! If electrolytics are found to be bad they should be replaced with similar, or same type...but sometimes they are no longer available. There are several people, and surplus houses, that specialize in old tektronix parts. Try them first. If they don't have them available either empty out the contents of the FP can and install new caps inside of it, or install something thats going to be as rugged as the rest of the scope itself. A simple test is to turn the vert gain all the way up and with the input shorted see at around 60 to 120 hz equivelent sweep speed if there is any hum visible in the waveform. You can also check the ripple with another scope too. If ripple's high replace the caps.
With the case of tube scopes many of them need vert amp tubes with as close to zero heater to cathode leakage as possible. Some scopes HAVE TO HAVE tubes with zero leakage no matter what or there will be hum visible in the trace as I mentioned above. If you purchase a classic tube scope this may be all that is wrong with it.
Solid State Scopes:
In solid state scopes the main thing thats seems to fail are power supply electrolytics, The black square Allen bradley mod pot potentiometers, and then selector switches. The 465B sweep switch may seem a bit loose on some scopes and its not really a rotary selector switch per say, but a plastic drum with indents that press against switch contacts soldered to the pcb. Theyn get turned on and off in different combinations. Be very careful with these contacts and clean only with pure alcohol...nothing else is needed nor will work safely and maintain specs. If it still does not function after cleaning then the contacts are shot and will have to be replaced. A good place to get parts for solid state TEK scopes is from Sphere Research in Canada. They have tons of NOS, used parts, and crt's. The 465 sweep switch is a bit tricky to work on and requires removal of the trigger board to be able to remove the sweep pcb. MAKE DIAGRAMS YOURSELF AS TO WHICH WIRE PLUGS IN WHERE BEFORE TAKING ANYTHING APART!!!!!!!
Keep them clean, especially in the high voltage section and by the intensity and focus pots. If things get dirty around there its possible things may fail as was mentioned in another post in this thread. ABOVE ALL IF THERE IS A FAN, IT MUST RUN!!!!!!!!! SEVERE DAMAGE TO ANY SCOPE WILL RESULT IF ITS FAN IS NOT RUNNING!!!!!!!!
Calibration is another thing all together. One can purchase used calibration equipment if he has alot of scopes to maintain, or of one can get the required equipment cheap. Otherwise repair the scope yourself and then spend the $$ and have it calibrated...if thats really important to you. Many calibration facilities are familiar with your equipment, even if it is really old. many times they can also get resultant specs out of them that way exceed the manufacturers specs, so a good calibration is simetimes well worth the price paid. Hope some of this helps out.
Mark
The Mother of All Tektronix Auctions
Looks like his wife is making him empty the garage -- Bricolo -- how much would it cost to ship 700 pounds to Strasbourg?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2530307172&category=4677
<em>OSCILLOSCOPES: (7) Oscilloscopes in all. The scopes are clean and the cosmetics are decent considering their age. There are a few dings, scratches, and label residue here and there but overall they look good. You may find a rare cracked knob. Unfortunately, I am short on power cords but these all take common household extension cords. I will throw in the only one I have at this time.
TWIN (2) QTY. TYPE 556 Oscilloscopes. These are true BOAT ANCHORS weighing in at 97 pounds apiece. One works great, the other seems to have a bit of a dim display, perhaps an adjustment of some kind?
(1) QTY. TYPE 545B Oscilloscope. This scope runs great. I have used this scope for about ten years and my good friend used it for about 20 years before that.
(1) QTY. TYPE 535A Oscilloscope. Powers up fine, has a weak display and needs work. Nice cosmetics and includes pop-up instruction manual on the case.
(1) QTY. TYPE 531 Oscilloscope. Inaccurate, erratic display, looks like a blown capacitor somewhere?, otherwise the screen is bright with a very beautiful and unusual blue-green phosphor.
(1) QTY. TYPE 533A Oscilloscope. Bright, inaccurate display needs work.
(1) QTY. TYPE 581 Oscilloscope. Bright display, no sweep (easy clue), needs work.
PLUG-INS: Altogether there are (14) QTY. PLUG-INS. Most are very clean and are cosmetically in good shape. Most work very well, others need work. I did not specifically write or test each one out for this auction but I have used several of them for years with no problems. To be on the safe side give it 70/30 with none DOA. I did not spell out all the specifications to save from tiring my typing fingers. You can find the specs readily available on the internet.
(5) QTY. TYPE CA PLUG-INS. Dual Trace Pre- Amplifier.
(1) QTY. TYPE D PLUG-IN. High-Gain Pre- Amplifier
(1) QTY. TYPE 53/54B PLUG-IN. Wide Band Pre- Amplifier
(1) QTY. TYPE B PLUG-IN. Wide Band Pre- Amplifier
(1) QTY. TYPE L PLUG-IN. Fast Rise Pre- Amplifier
(1) QTY. TYPE 82 PLUG-IN. Dual Trace Pre- Amplifier
(1) QTY. TYPE G PLUG-IN. Wide Band Differential Pre- Amplifier
(1) QTY. TYPE 1A4 PLUG-IN. 4 Channel Amplifier
(1) QTY. TYPE 1A1 PLUG-IN. Dual Trace Pre- Amplifier.
(1) QTY. TYPE 1A2 PLUG-IN. Dual Trace Pre- Amplifier.
ACCESSORIES: These accessories are clean, power up, and are cosmetically decent. I have not tested them otherwise.
(1) QTY. TYPE 121 Wide Band Pre-Amplifier, with Manual.
(1) QTY. TYPE 128 Probe Power Supply, with Manual.
(1) QTY. TYPE 500/53A SCOPE MOBILE. This cart is in very good looking shape. It features two extra Plug-In BAYS, a nice tool drawer, a bottom tray, and (3) 117 VAC accessory plugs on the back panel. The wheels roll freely and also have a braking mechanism to stop the cart from rolling when in place.
Looks like his wife is making him empty the garage -- Bricolo -- how much would it cost to ship 700 pounds to Strasbourg?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2530307172&category=4677
<em>OSCILLOSCOPES: (7) Oscilloscopes in all. The scopes are clean and the cosmetics are decent considering their age. There are a few dings, scratches, and label residue here and there but overall they look good. You may find a rare cracked knob. Unfortunately, I am short on power cords but these all take common household extension cords. I will throw in the only one I have at this time.
TWIN (2) QTY. TYPE 556 Oscilloscopes. These are true BOAT ANCHORS weighing in at 97 pounds apiece. One works great, the other seems to have a bit of a dim display, perhaps an adjustment of some kind?
(1) QTY. TYPE 545B Oscilloscope. This scope runs great. I have used this scope for about ten years and my good friend used it for about 20 years before that.
(1) QTY. TYPE 535A Oscilloscope. Powers up fine, has a weak display and needs work. Nice cosmetics and includes pop-up instruction manual on the case.
(1) QTY. TYPE 531 Oscilloscope. Inaccurate, erratic display, looks like a blown capacitor somewhere?, otherwise the screen is bright with a very beautiful and unusual blue-green phosphor.
(1) QTY. TYPE 533A Oscilloscope. Bright, inaccurate display needs work.
(1) QTY. TYPE 581 Oscilloscope. Bright display, no sweep (easy clue), needs work.
PLUG-INS: Altogether there are (14) QTY. PLUG-INS. Most are very clean and are cosmetically in good shape. Most work very well, others need work. I did not specifically write or test each one out for this auction but I have used several of them for years with no problems. To be on the safe side give it 70/30 with none DOA. I did not spell out all the specifications to save from tiring my typing fingers. You can find the specs readily available on the internet.
(5) QTY. TYPE CA PLUG-INS. Dual Trace Pre- Amplifier.
(1) QTY. TYPE D PLUG-IN. High-Gain Pre- Amplifier
(1) QTY. TYPE 53/54B PLUG-IN. Wide Band Pre- Amplifier
(1) QTY. TYPE B PLUG-IN. Wide Band Pre- Amplifier
(1) QTY. TYPE L PLUG-IN. Fast Rise Pre- Amplifier
(1) QTY. TYPE 82 PLUG-IN. Dual Trace Pre- Amplifier
(1) QTY. TYPE G PLUG-IN. Wide Band Differential Pre- Amplifier
(1) QTY. TYPE 1A4 PLUG-IN. 4 Channel Amplifier
(1) QTY. TYPE 1A1 PLUG-IN. Dual Trace Pre- Amplifier.
(1) QTY. TYPE 1A2 PLUG-IN. Dual Trace Pre- Amplifier.
ACCESSORIES: These accessories are clean, power up, and are cosmetically decent. I have not tested them otherwise.
(1) QTY. TYPE 121 Wide Band Pre-Amplifier, with Manual.
(1) QTY. TYPE 128 Probe Power Supply, with Manual.
(1) QTY. TYPE 500/53A SCOPE MOBILE. This cart is in very good looking shape. It features two extra Plug-In BAYS, a nice tool drawer, a bottom tray, and (3) 117 VAC accessory plugs on the back panel. The wheels roll freely and also have a braking mechanism to stop the cart from rolling when in place.
For general purpose audio work one of those old tube Tektronix's is hard to beat!! You guys ought to be able to recognize a piece of great equipment when you see it....hopefully. There is a classic TEK tube scope that doesn't require your Uncles garage to store.....read on.
Aside from my TEK 7704A, 7623, 456B, and many pieces of TM500 gear, the scope I use the most for audio work is a restored 1951 Tektronix 315D!! Its single trace, 5mhz, 41 vacuum tubes, turbo fan, and wonderful triggering abilities all add up to a classic piece of test gear well worth saving from the dump. This was Tektronix's second product!
Interestingly when I restored it there were no bad tubes, just replacing the bypass caps, reforming the main electrolytics, and cleaning and alignment brought it back to spec again. Even the main power supply electrolytics are still good in this scope, and they are 52 years old! I'd like to see a transistorized unit, even a TEK, beat those odds. On the 2225....be careful as most of the hybrid circuits are long obsolete and N.L.A.......You will have to scrap out another scope to keep that one going. Go to Yahoo and sign up for the TEKSCOPES forum and learn more about all the Tektronix test gear. There are many retired Tektronix Field Service Techs that frequent the site and can give you valualble help in choosing a good scope.
http://groups.yahoo.com/group/TekScopes/
Mark
Aside from my TEK 7704A, 7623, 456B, and many pieces of TM500 gear, the scope I use the most for audio work is a restored 1951 Tektronix 315D!! Its single trace, 5mhz, 41 vacuum tubes, turbo fan, and wonderful triggering abilities all add up to a classic piece of test gear well worth saving from the dump. This was Tektronix's second product!
Interestingly when I restored it there were no bad tubes, just replacing the bypass caps, reforming the main electrolytics, and cleaning and alignment brought it back to spec again. Even the main power supply electrolytics are still good in this scope, and they are 52 years old! I'd like to see a transistorized unit, even a TEK, beat those odds. On the 2225....be careful as most of the hybrid circuits are long obsolete and N.L.A.......You will have to scrap out another scope to keep that one going. Go to Yahoo and sign up for the TEKSCOPES forum and learn more about all the Tektronix test gear. There are many retired Tektronix Field Service Techs that frequent the site and can give you valualble help in choosing a good scope.
http://groups.yahoo.com/group/TekScopes/
Mark
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