Shopping for a used oscilloscope in the oscilloscopes signal spectrum analyzers category means balancing what a two-channel digital scope can do against what you want to spend. The Tektronix TDS 380 and HP 54600B are both used two-channel digital scopes, but they aim at different parts of that trade-off.
Quick verdict
If your bench sees fast digital or analog signals, the Tektronix TDS 380 is the stronger choice because it combines high bandwidth with fast real-time sampling. If you mostly work with audio, control, or other slower signals, the HP 54600B covers that ground for a lower listed price.
At a glance
| Product | Listed Price | Max Bandwidth | Channels | Condition | Price Bar |
|---|---|---|---|---|---|
| Tektronix TDS 380 400MHz 2GS/s 2 Channel Digital Real-Time Oscilloscope Tested | USD 195.00 | 400 MHz | 2 | Used | |
| HP 54600B Digital Oscilloscope W/ Front Cover + Case | USD 135.00 | 100 MHz | 2 | Used |
Where each product wins
Where the Tektronix TDS 380 wins: raw performance and connectivity. It steps well beyond the HP in bandwidth and sampling speed, and its rear I/O includes RS-232, Centronics, GPIB, and video output. If your measurements involve quick edges or timing details, the extra capability is meaningful.
Where the HP 54600B wins: purchase price and convenience. It comes in below the Tektronix on listed price, and the title includes a front cover and case for storage and carrying. For simpler signals and lower out-of-pocket cost, that is a practical combination.
Product notes
#### Tektronix TDS 380
If fast signal changes are a regular part of your day, the Tektronix TDS 380 is the two-channel scope to start with. The title is explicit: 400 MHz bandwidth, 2 GS/s sampling, and a Tested condition note. It also lists autoset, measure menu, hardcopy, and math functions, plus rear ports for RS-232, Centronics, GPIB, and video output. That makes it a more complete bench tool for someone who moves between signal types. The limitation is the higher listed price compared with the HP, and for ordinary lower-frequency measurements that extra performance may go unused. It is still a used unit, so the usual used-instrument caveats apply, but the headline specifications point clearly to a scope built for faster signal work.
#### HP 54600B Digital Oscilloscope W/ Front Cover + Case
The HP 54600B makes more sense when your work stays within 100 MHz. It is the lower-priced option in this pair, and the title mentions a front cover and case, which is a nice touch for a scope that needs to move between workspaces. The two-channel digital design covers the basics: 100 MHz maximum bandwidth, HP 54600B model identification, and a used power-on-tested condition. The catch is the same spec that keeps the price lower: 100 MHz is the ceiling, so it is not the tool for signals that need the Tektronix's higher bandwidth and faster sampling. For audio, control, and general-purpose troubleshooting, that trade-off is often acceptable.
Final choice by use case
Choose the Tektronix TDS 380 for high-bandwidth work, faster sampling demands, or when rear connectivity like RS-232, GPIB, Centronics, and video output matters to your setup. Choose the HP 54600B when your signals are lower-frequency and the lower listed price, front cover, and case are what you want. Both are used two-channel digital oscilloscopes; your signal speed and spending plan decide the winner.
