Tektronix 2440 500MS/s 2-Channel Digital Oscilloscope 135213649220 the frequency dial does change

the frequency dial does change the output similar to how it's supposed too

Manufacturer Pioneer Model Number CT-F2121 SKU 19-81300 Ref 23-117647

Manufacturer Marantz Model Number EQ140 SKU 19-77186 Ref 23-111087

Manufacturer Netgear Model Number JGS516PE SKU 19-82729 Ref 23-119986

Manufacturer Lutron Model Number HQRD-PRO-WH UPC 784276270724 SKU 19-77780 Ref 23-123622

Tektronix 2440 500MS/s 2-Channel Digital Oscilloscope 135213649220 the frequency dial does changeCondition Used Description This item is fully tested and in excellent working order. Item will come with a 30 Day Warranty. Cosmetically in good condition showing minor scuffs scratches blemishes from previous use. There is pen marking on top of front faceplate and engraved letters on side of front faceplate. Includes 2 Channel Digital Oscilloscope as pictured. No additional items or accessories are included. Unless pictured, no power adapter power