What would be a good Scope to use for FM alignment and what would I expect to pay?
Thanks,
Frank

Would you be using this scope in conjunction with a sweep generator? If so, just about any scope with an external horizontal input should do. It doesn't need to be fancy if this is all you are going to use it for. You could probably find one at a hamfest in the $15 - $25 range. But I would get something useful for other purposes as well.

Dave

Dave, I am still relatively new to the hobby but I am getting more proficient as I go along and my interests are getting more diverse as well. Having said that,I still am not sure what to look for. I have an idea that I am willing to spend up to $250 or so for a good scope that doesn't need any work and has more capabilities than just simple alignment but as yet I don't know what the other needs might be. I just don't want to buy something that I will be dissatisfied with in a years time.
Frank

Your price point should definitely get a scope you could be happy with in the long term. I'd recommend a Tektronix Oscilloscope in the 30 to 150MHz range and there are several models which would do well.

Although I have a soft spot for old Tek tube scopes I'd advise you look at their 400, or 2400 series scopes. All are solid state with the exception of the CRT, and produced from the 70's to the 90's.

Pretty much any dual trace analog oscilloscope of 100 MHz or so will have everything you are ever likely to use and be difficult to grow out of for hobby use, plus just about any of them on the used market can be found in good working order well below your anticipated $250.00 price. The Tek 465/475 are good choices in reliable scopes, as are HP 1740/41A's- those are a few I have experience with but there are MANY others that would fill the bill too.

-Mark-

I have been looking at the Tek scopes on ebay and many don't come with probes or even power cords. Some are offering 2 new probes but I suspect that these are cheap Chinese made probes. Are they good enough for radio work?
Also, how big a deal is the calibration? Most I have seen are out of date on the calibration. Does it make sense to pay more for one that has been calibrated?
Thanks,
Frank

I suspect the Chinese probes will be avg. to below avg. quality. I've even seen a popular brand name like B&K not hold up well. For a budget of $250 you can get some very nice working, used Tek or HP scopes complete with probes, manuals, etc. from on-line auctions. They may not be recently calibrated but for your needs, that's not critical. The idea is to get something that's reliable, stable, with most replacement parts still available.

With test equipment, power cords are most often supplied, but probes and "test leads" aren't. If they don't say, or you don't see them, ask the seller. Chinese probes are cheap, and not as rugged as Tek or HP probes, but will work well, and last quite a long while, with a little TLC. When buying probes, always buy units with MHz ratings about twice, or better, than your scopes specs, this will allow your scope to perform closer to its specs.

Mike, what about original factory supplied probes, Do they need to be rated higher than the bandwidth of the scope too? I am looking at a Tek 465 that looks to have factory supplied probes included .
Thanks,Frank

BTW, I am originally from KCMO

hello Frank,

with 250$ I would buy a 7000 series Tek scope. This is more heavy, but it works with plugins.
When you have killed the input you will know the different, another plugin for low bucks and the scope is healty again.
All other scopes will go in repair. Also there are some useful plugins to expand the possibilitys later.

greetings
Martin

If you want the optimum out of the scope, the short answer is yes. Tektronix made hundreds or different probes, and I don't know what probes were supplied with the various models. As the signal applied to a scope goes up in frequency, it reaches a point where its displayed amplitude starts to decrease, and as frequency goes up even further the displayed amplitude continues to get smaller and smaller.

A scopes "bandwidth" is that frequency at which the amplitude of a the displayed signal has been reduced by approximately 30%. Probes have a similar response, and the signal reductions of the scope and probe add to each other, therefore if the scope and probe have the same ratings, the displayed signal will be one half the original aplitude at the scopes "rated bandwidth." So, you want the probe's frequency response to be at least 1-1/2 times higher that that of the scope, in order to enjoy the scopes full bandwidth response.

If you want some specifications on Tek scope probes GO HERE, and scroll down to the "P" prefix and within the range of 6000 to 7500. The Tek products is a very long list, so its down quite a way.

This site is a great site for looking up test equipment to at least get a brief discussion, and a picture, in most cases.

If FM alignment is the goal, you need to put the horse before the cart and consider what you'll be using for a sweep generator. Over the years, the design and capabilities of sweep generators changed to keep up with scope capabilities.

Problem is, an up-to-date sweep generator may set you back considerably more than the scope will.

Older sweep generators were designed for 60-Hz AC "line lock" with recurrent sweep scopes. Just about any scope can be made to work this way, but you might be wasting money if you buy a HP or Tek scope loaded with confusing features you'll never need or use. A plain service bench scope like a Leader, B&K, or Philips will work fine, and these can often be had for less money than the high-end units.

Later sweep generators usually have built-in horizontal and vertical drives, and often built-in demodulators as well. External blanking and triggering are typically provided. To fully take advantage of these features, a scope which has compatible trigger and blanking inputs is needed.

I think the 2000 series would do you well. The 465/75 were nice scopes but all seem to eventually develop attenuator issues and can be hard to fix, but not impossible. My one concern with a CRT scope is the condition of the CRT itself. Make sure you can get a sharp bright trace. Other problems in the scope could affect this to some extent, but a weak tube is usually easy to spot, after you are sure the astig. and focus are set correctly. Buy only if you are allowed to plug it in and see what it does. Or have an outlet somewhere within reach. Do no take the sellers word for it except maybe at a retail establishment where you have recourse. And hopefully, with a probe or some way to connect to the calibrator output test point to confirm the vert. attenuators are working right.