Protek B801 Manual Link -

: Common features include Data Hold, Min/Max/Avg recording, and RS-232 interfaces for data logging.

TTL sync output and VCF (Voltage Controlled Frequency) input for 100:1 tuning range. protek b801 manual link

Alternatively, the manual is also mirrored on product page for the B801 (SKU: PTK-801). Look for the "Documents" tab next to the product images. : Common features include Data Hold, Min/Max/Avg recording,