Monday, November 9, 2015

More work on my old FT726R

As previously mentioned  in my blog I thought I had fixed the sticky contacts on the relay in the 144MHz module of my old FT726R. The adjustments only lasted 6 months, so it was time to make a more permanent fix

I made a  long search for a replacement relay, but found none, mainly because of the non standard pin configuration. It was time to try another way.  I found some DPDT 12v relays in my collection of around the same size, but with totally different (normal) pinouts. It was not possible to drill new mounting holes for the pins, The only option was to glue it upside down on the PCB and put wires from the relay pins to the corresponding PCB tracks

Original Relay with cover removed after previous relay contact adjustments

Relay Removed

Replacement Relay hand wired in place

While I had the radio open i fitted an extra cable to allow an external preamp output to be connected  to the 2m module receive input, without the risk of transmitting up the back end of the preamp.
External 2m Receive Input cable(exiting module to left)