First a scope is a scope. I fail to see what your gender has to do with it. But perhaps you see something I don't.
New vs. used? The prices for new digital scopes today are so reasonable that I see little reason for buying used as a first scope. Perhaps later when you know more about what you might be getting into, but I would not recommend a used one now.
The repair of basic level things don't really require a scope. I worked for 55+ years in electronic repair on many levels, often as the best in the house, and can honestly say that 95% of my repairs were accomplished with analog VOMs. There is nothing magic about a scope. What is needed is a very good appreciation of Ohms Law.
4 vs 2 channel? Again, 55+ years of experience and I never used a 4 channel scope.
200 to 300 USD. A lot of very good entry model scopes can be purchased in that range. No need to strain your budget.
Bandwidth? 20 Mhz? 50 Mhz? 100 Mhz? 150 Mhz? 200 Mhz? What are you going to work on? Microprocessors or full blown computers? I can tell you right now that you are not going to figure out a lot just looking at a processor pin wiggle up and down at any of those rates. All you really see is if it is wiggling or not. And a logic probe can tell you that. Audio? We are talking KHz, not Mhz. Base band video? 20 Mhz is probably enough for all but the highest HD video. AC power equipment? 50 or 60 Hz - no Khz, no Mhz, no GHz there.
However, in many digital circuits the bandwidth of the circuit can be important. A high band width scope can allow you to see the rise and fall times of digital signals and thereby know if they may be rounded off too much for proper operation.
So for a beginner I would not get too wound up in all those nice sounding specs. Now, there are some things that MAY help with specific things. Some scopes, even beginner level scopes offer things like the ability to decipher various digital signals. But different digital signals do use different protocols so a "filter" that reads one type of signal will only show garbage on others. And there are hundreds of digital protocols out there. So if you are interested in any particular ones, look for them in your selection. But don't expect one scope to read them all unless it costs a king's ransom.
Another thing that can be important is triggering. In order to see a signal, the trace on the scope must start at a point just before it occurs. How is this done? With repetitive signals a trigger can be delayed from the previous instance of the signal. With digital scopes, the signal itself can act as the trigger if the observed values before it are stored for use when that trigger arrives. This is a great advantage of digital scopes over many/most analog ones. And many times you may wish to see events that only occur at long and possibly random intervals. They can be very challenging.
The ability to see low level signals can be important in some kinds of work.
Be sure that whatever scope you choose, to get some 10X probes for it. The 10X probe attenuates the signal level by that amount, but it usually allows a much higher bandwidth to be displayed. It is the de-facto standard probe for most work.
thanks
-avgrespondic: i would like to buy new, I prefer
I try to fix anything on a basic level: audio device if don't start, any household appliance, power supply... nothing difficult.
my intention is to start studying the oscilloscope starting from the basics
-Sahko123: but ds1054z is 4 channel, is not inconsiderate for me? 2 channel is not sufficient?
-tgzzz: thanks for warning! in general I am very attentive to safety, Every time before operating I discharge the capacitors using my special kit.
I will be well informed on the use of the probes
-rstofer: as price range I had indicated rigol 1052 or max 1202z-e (similar price..)
The siglent 1104 it's too much money for me
I don't make electronic plans.. I only do troubleshooting on the electronic boards
Now I only use multimeter and power supply bench, but I would like to learn to find faults also using the oscilloscope.
I would like to understand:
- for my use, is not sufficient 2 channel?
-for my budget, the bandwidth range is 50 to 200 max mhz... with 200 mhz I have many more possibilities (compared to 100mhz?)
For example the microprocessors in my amplifier work a 20mhz..
I want to start playing with the oscilloscope from the simplest things, your buying advice is very useful
Charlotte