Here’s the 3rd video in the Command Technologies HF-2500 teardown and rebuild by Steve G0UIH – Vortex Antenna Systems/Q82.uk. Here in Part 3, we’ve plenty of images taken whilst stripping down the front panel and investigating the rotary band switch which electronically switches the relays in the rear tuning circuit.
The original rotary switch has problems. During manufacture, it seems there is a punched steel plate which as ‘fingers‘ that protrude vertically. These fingers prevent the switch from turning past a certain point [in both directions]. In this switch, the minimum position is for the 10m band. However, the switch has a bent stopper finger – so when used on 10m, the amp would frequently not key because the switch had move past its minimum position so was ‘floating’ with no contact being made.
When we tried to straighten the ‘finger’ it just broke away. Also, the switch was in a very poor state electrically. The contacts were worn and it wasn’t worth trying to salvage. See later on when we fit a new ‘RS Components’ single pole 6-way switch of a much better quality.
See the Video Part 3 – Front Panel and Rotary Switch
Click on any of the images below for a larger hi-res version.
Enables the 8 Wires to the Meter Board to be Easily Disconected
