Oscilloscope

[richardcooper2k]

if you want to build one the babani book is available from amazon for £4. also in the book are : test bench amplifier, high resistance voltmeter, transistor tester, capacitance meter, AF frequency meter, analogue probe, CMOS probe, TTL probe. there's a load of similar books if you do a search on amazon for 'test equipment construction'
ive never bought a 'proper' one so someone else will have to post about that and the relative merits