I have no formal electronics training. just what I learned along the way
as a ham for 45 years. I am interesting in learning about and how to use oscilloscopes. I would like to learn how to trace and debug digital as well as analog radio circuits. I'm have an old Elenco 1251 dual-trace 20mhz. No idea how well it works or how well calibrated. I was thinking of finding something a little newer and maybe better bandwidth. Any recommendations on a good used scope? Any thoughts on any books that might provide a useful overview of using a scope to debug rf and digital problems? Any assistance gratefully appreciated, 73, Doug -- KØDXV _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Doug
I would recommend a 100 MHz scope. I have an old Philips one that is great for HF and 50 MHz use. I'm not sure about books to describe how to use a scope, there isn't much to using one and there's plenty of information on the web, see http://www.doctronics.co.uk/scope.htm as an example. 73 Dave, G4AON K2 #1892, K1 #1154 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Doug Person
Doug,
Paul Harden N5AN has written good articles on the use of the oscilloscope. One can be found in text format in the QRP-L archives at http://home.frognet.net/~mcfadden/wd8rif/archives.htm - I know there are other places where this info appears, but I don't have handy references at the moment. If you are doing nothing but observing RF voltages with your 'scope you might be able to get by with your 20 MHz 'scope, but I recommend a 100 MHz scope. As for buying an oscilloscope, I highly recommend purchasing one from Bob Garcia. He is known as 'Mr. Scope' and frequents many of the hamfests in the Southeast (he lives in GA). I have recently have had dealings with him and can say that he is more than fair both in price and his manner of doing business. You can email him at mailto:[hidden email] and ask him what he has available. To make good use of the 'scope without loading the circuit under test, you will need some good 10X scope probes. The probes have a frequency rating too and should be rated for 100 MHz or higher for use in the HF ham band region. Regarding frequency ratings of probes and 'scopes - the rated frequency is the point where the response drops off by 3 dB, so 100 MHz will provide good calibrated readings at 1/10th of the frequency rating and is quite usable up to 1/3 the frequency rating. In other words, the response of a 100 MHz 'scope will be quite accurate through 10 MHz and reasonably accurate at 30 MHz, but will drop off significantly above 30 MHz. You will still be able to use the 'scope up to its frequency limit (and maybe above), but you should not trust the voltage measurements made with it at those limits (the waveforms may show some distortion at the limits too). 73, Don W3FPR > -----Original Message----- > > I have no formal electronics training. just what I learned along the way > as a ham for 45 years. I am interesting in learning about and how to > use oscilloscopes. I would like to learn how to trace and debug digital > as well as analog radio circuits. > > I'm have an old Elenco 1251 dual-trace 20mhz. No idea how well it works > or how well calibrated. I was thinking of finding something a little > newer and maybe better bandwidth. > > Any recommendations on a good used scope? Any thoughts on any books > that might provide a useful overview of using a scope to debug rf and > digital problems? > > Any assistance gratefully appreciated, > > 73, Doug -- KØDXV > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
I'm looking at a Tektronix 2213A Dual Trace 60MHz scope. Its going for
$150 on ebay. Its a nice compact unit. Anyone familiar with this unit? I know there were many recommendations to go with 100MHz. But most anything in good shape in that range is a little outside my budget. Any opinions appreciated. 73, Doug -- KØDXV _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Doug Person wrote:
> I'm looking at a Tektronix 2213A Dual Trace 60MHz scope. Its going > for $150 on ebay. Its a nice compact unit. Anyone familiar with this > unit? I know there were many recommendations to go with 100MHz. But > most anything in good shape in that range is a little outside my budget. > Any opinions appreciated. > > 73, Doug -- KØDXV > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > > better. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Doug Person
Everyone has favorites, but the older Tek analog scopes are very solid and a good deal. If you have the room, you can get amazing performance/cost from 7000 series scopes. I have a 7854 (400 mhz plus waveform digitizing) and a 7934 (500 Mhz Analog storage) 7000s run from 100mhz to 1Ghz in bandwidth, and, depending upon the plug-ins chosen, you can do just about anything with a 7000 series. Their primary drawback is size. Both of my scopes are on carts because they would take up a big chunk of my bench, otherwise.
Tek also made a very nice series of "portable" scopes. The 100 Mhz 2246 is very nice and readily available used. It has the added bonus of "smart cursors" to easily measure amplitude and period/frequency with a single button push, and I have found the triggering to be quite good. The 2400 series, and particularly the 2465s are also nice pieces of equipment, but are more expensive due to their greater bandwidth. What you "need" really depends on what you "want" and what you are going to do with it. The higher bandwidth devices are useful if you need to look at abberations in a signal that may be smoothed out in a lower bandwidth scope, but may be unnecessary if you just want to trace a signal through a circuit and measuring changes in amplitude or phase. Extra bandwidth is never a bad thing, it just costs more, and may not be necessary. Now to stir up the controversy, I used to have a Tek 465. This is a venerable 100 Mhz scope, but frankly the 2246s that I have had worked better and were much easier to use. So, I would recommend a scope more recent than the 465/475 series. But there are lots of these still out there and are very much liked by some. My one experience repairing a 465 may have colored my view. Howard W. Ashcraft, Jr. W1WF ***************************** This communication, including any attachments, is confidential and may be protected by privilege. If you are not the intended recipient, any use, dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please immediately notify the sender by telephone or email, and permanently delete all copies, electronic or other, you may have. To ensure compliance with requirements imposed by the IRS, we inform you that any tax advice contained in this communication (including any attachments) was not intended or written to be used, and cannot be used, for the purpose of (i) avoiding penalties under the Internal Revenue Code or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein. The foregoing applies even if this notice is embedded in a message that is forwarded or attached. ***************************** _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
One thing I have not seen mentioned so far is the probes that you will need
to use. The scope's 1:1 normal probe will place a fairly large capacitance across the device you are measuring and the amount will depend on the quality of the probe you buy. If the signals you intend to measure are fairly large, then it is very well worth while using at least a 10:1 or even 100:1 probe as these put a much smaller capacitance across your signal source. That means the scope has to handle a smaller signal. Original Tek probes are very expensive and a new one might cost the same as that second hand scope! The probes are sometimes powered from a special socket on the scope, so be careful you buy one appropriate to the scope. I should also point out that it would be unusual to want to see the individual sine wave trace; you would normally only see a wide green bar across the face of the scope representing the amplitude. This is a peak to peak waveform and you will need to divide it by 2.828 to get to the rms value. The time base setting is much lower than the waveform you are measuring. By the way, scopes are rarely better than 5% accurate and do drift, they are not meant for precision measurement. Those modern scopes that do the calculation for you save a bit of time and you might normally need another instrument to measure the rms voltage (again with a precision probe). This all depends on the waveform being well within the -3dB measurement limits. Of course you can still measure - even beyond the -3dB limit if you have previously done a calibration with various signals so you know the performance at higher frequencies. Just because a scope is spec'd to only say 20MHz doesn't mean it cannot be used beyond that: you just have to know what that performance is. Don't expect to see sinewaves. If the signal is strong enough, you don't even have to make contact. Just laying the probe nearby can get you an indication and not upset the circuit too much. You can make *comparative* measurements like this, ie adjust a control while watching the scope for peaking purposes. David G3UNA ----- Original Message ----- From: "Howard W. Ashcraft" <[hidden email]> To: "Doug Person" <[hidden email]>; <[hidden email]> Sent: Sunday, November 26, 2006 10:26 PM Subject: RE: [Elecraft] Recomendations on Oscilloscopes Everyone has favorites, but the older Tek analog scopes are very solid and a good deal. If you have the room, you can get amazing performance/cost from 7000 series scopes. I have a 7854 (400 mhz plus waveform digitizing) and a 7934 (500 Mhz Analog storage) 7000s run from 100mhz to 1Ghz in bandwidth, and, depending upon the plug-ins chosen, you can do just about anything with a 7000 series. Their primary drawback is size. Both of my scopes are on carts because they would take up a big chunk of my bench, otherwise. Tek also made a very nice series of "portable" scopes. The 100 Mhz 2246 is very nice and readily available used. It has the added bonus of "smart cursors" to easily measure amplitude and period/frequency with a single button push, and I have found the triggering to be quite good. The 2400 series, and particularly the 2465s are also nice pieces of equipment, but are more expensive due to their greater bandwidth. What you "need" really depends on what you "want" and what you are going to do with it. The higher bandwidth devices are useful if you need to look at abberations in a signal that may be smoothed out in a lower bandwidth scope, but may be unnecessary if you just want to trace a signal through a circuit and measuring changes in amplitude or phase. Extra bandwidth is never a bad thing, it just costs more, and may not be necessary. Now to stir up the controversy, I used to have a Tek 465. This is a venerable 100 Mhz scope, but frankly the 2246s that I have had worked better and were much easier to use. So, I would recommend a scope more recent than the 465/475 series. But there are lots of these still out there and are very much liked by some. My one experience repairing a 465 may have colored my view. Howard W. Ashcraft, Jr. W1WF ***************************** This communication, including any attachments, is confidential and may be protected by privilege. If you are not the intended recipient, any use, dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please immediately notify the sender by telephone or email, and permanently delete all copies, electronic or other, you may have. To ensure compliance with requirements imposed by the IRS, we inform you that any tax advice contained in this communication (including any attachments) was not intended or written to be used, and cannot be used, for the purpose of (i) avoiding penalties under the Internal Revenue Code or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein. The foregoing applies even if this notice is embedded in a message that is forwarded or attached. ***************************** _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Doug Person
I have used a 465 for many years -Cut my teeth in the Navy with one. They were very fine scopes. The issue is that they used a lot of custom parts that are now made of un-obtanium
as far as I know. A couple of years ago, Tektronix had a $200 trade in offer on their TDS series. At the time, I was repairing guitar amps on the side, so I took the plunge and got a TDS 2012 100 Mhz. Those guys have never lost the art of making a good scope. -Pete wd4lst > Now to stir up the controversy, I used to have a Tek 465. This is a venerable 100 Mhz scope, but frankly the 2246s that I have had worked better and were much easier to use. So, I would recommend a scope more recent than the 465/475 series. But there are lots of these still out there and are very much liked by some. My one experience repairing a 465 may have colored my view. > > Howard W. Ashcraft, Jr. W1WF _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Doug Person
Doug,
Tektronix has a scope primer called "XYZs of Oscilloscopes" It can be found on the web at http://tinyurl.com/yx46uv (That link should take you to the Tektronix website) Hope this helps, Pete wd4lst > > From: Doug Person <[hidden email]> > Date: 2006/11/26 Sun AM 01:39:50 CST > To: [hidden email] > Subject: [Elecraft] Recomendations on Oscilloscopes > > I have no formal electronics training. just what I learned along the way > as a ham for 45 years. I am interesting in learning about and how to > use oscilloscopes. I would like to learn how to trace and debug digital > as well as analog radio circuits. > > I'm have an old Elenco 1251 dual-trace 20mhz. No idea how well it works > or how well calibrated. I was thinking of finding something a little > newer and maybe better bandwidth. > > Any recommendations on a good used scope? Any thoughts on any books > that might provide a useful overview of using a scope to debug rf and > digital problems? > > Any assistance gratefully appreciated, > > 73, Doug -- KØDXV > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > Pete Axson WD4LST 17901 NE 18th Ave Citra, FL 32113 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
[hidden email] wrote:
> Doug, > Tektronix has a scope primer called "XYZs of Oscilloscopes" > It can be found on the web at http://tinyurl.com/yx46uv > (That link should take you to the Tektronix website) > Also their e-learning O-scope tutorials found here http://www.tek.com/Measurement/cgi-bin/framed.pl?Document=/Measurement/tutorials/index_scopes.html%3Fwt%3D465%26link%3D/Measurement/tutorials/index_scopes.html&FrameSet=elearning -- GB & 73's KA5OAI Sam Morgan _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by wd4lst
One great place to look is www.govliquidation.com.
Its an auction site for the liquidation of government assets. I bought a 465B in great shape for 65 bucks. Its a little more involved than e-Bay (but only a little). The involvement is that you have to arrange for a pickup and shipment of whatever you buy. I think I paid 50 bucks to have someone go to the site, box it and send it via fedex. Its not a big deal as there are lists of companies that do this for every site selling goods, you just have to email and get the best price on boxing and shipping. I have bought a couple of things off the site and am very pleased with it. Take a look! Neal - k3nc On Nov 26, 2006, at 10:38 PM, <[hidden email]> <[hidden email]> wrote: > Doug, > Tektronix has a scope primer called "XYZs of Oscilloscopes" > It can be found on the web at http://tinyurl.com/yx46uv > (That link should take you to the Tektronix website) > Hope this helps, > Pete > wd4lst >> >> From: Doug Person <[hidden email]> >> Date: 2006/11/26 Sun AM 01:39:50 CST >> To: [hidden email] >> Subject: [Elecraft] Recomendations on Oscilloscopes >> >> I have no formal electronics training. just what I learned along >> the way >> as a ham for 45 years. I am interesting in learning about and how to >> use oscilloscopes. I would like to learn how to trace and debug >> digital >> as well as analog radio circuits. >> >> I'm have an old Elenco 1251 dual-trace 20mhz. No idea how well it >> works >> or how well calibrated. I was thinking of finding something a little >> newer and maybe better bandwidth. >> >> Any recommendations on a good used scope? Any thoughts on any books >> that might provide a useful overview of using a scope to debug rf and >> digital problems? >> >> Any assistance gratefully appreciated, >> >> 73, Doug -- KØDXV >> >> >> _______________________________________________ >> Elecraft mailing list >> Post to: [hidden email] >> You must be a subscriber to post to the list. >> Subscriber Info (Addr. Change, sub, unsub etc.): >> http://mailman.qth.net/mailman/listinfo/elecraft >> >> Help: http://mailman.qth.net/subscribers.htm >> Elecraft web page: http://www.elecraft.com >> > > Pete Axson > WD4LST > 17901 NE 18th Ave > Citra, FL 32113 > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Free forum by Nabble | Edit this page |