When it comes to SMD though, you might want to look into "hot air" stations for that type of work, far easier than using a soldering iron.
Since technology for this has advanced, some older Air Stations are still viable for most main-plane SMD work, some main reasons for the resale is due to the delicate nature of the microminiaturization and increased complexity of the trace and foil layering designs requiring a more dedicated narrow feeder/blower system with higher tolerance controls.
Else, other aspects of the Oscilloscope is - don't just buy a simple scope, although great for low-cost, what about those other features? Like Frequency Counter and time domain and snapshot multi-trace input and display - might help you in seeing not just RF issues but the CPU communication to and from other devices on the main PCB for SIGNATURE analysis - different from Spectrum Analysis - which is more dedicated to RF signatures than the digital side of the communication process to make it go...
To give you specific models - heck I cannot even begin to state the obvious, there's a lot out there and those offshore accounts are adding more to the eBay junkpile every day. Just find a used one with a counter in it - or review the YT vids and see just how much they fiddle with these display icons and on-the-shelf-and-don't-touch-it-devices - meaning they only use it to show a feature or quirk because they finally figured out enough of the owner's manual to make it do something - not just sit there...which, in their vids - is doing just that...
When you invest money, you have to look at the ability for ROI (Return On Investment) - if it's a labor of love, you don't need to spend much because of mentioning the receiver parts earlier.
You achieve a level of performance using simple tools that many accept as standard - the stuff between the ears interprets. And how good you sound is from your level of experience and the knowledge gleaned - it's done by monitoring the signal thru another receiver - just don't go by using headphones on a tape monitor loop off the receiver itself - Listen to your signal thru another radio you know, as your reference radio - to prove you are ok, the problem is on the other end - not you.
