IC706 classic repair

IC706 classic  was damaged by high RF at 144 input
I use this old but very good rig as 146-148  i.f for 1296MHz  XVTR
Receiving Graves at 143.050  pings and scatter i forgot to disconnect the VHF antenna   ( 3 band 6,4,2) when transmitting at 6m with the 7 el just underneath so it became very quiet at 23 / 144..
144-148 /VHF input circuit part with 3-PIN antenna switch  and MA862 band switch that switches between 2 input filters. TOP = 60-200 MHz  down is 144-148 bandpass
preselection in front of the    uPC1658G  wide band preamp



MA862  bandswitch fried by high 50MHz signal at 144 /VHF input SO239


replaced by 2 BA891 bandswitch diodes Ebay 



above temporary jumper to select 144-148 band pass filter
without the bandswitch diodes the IC706 does not switch to the VHF filter when tuning outside the 144-148 range  a solution without bandswitch
But the burned out  MA862 protected the IC706 preamp against further serious damage
So it is better to have  bandswitch diodes placed there
4 pole tuner connection covering 144 input circuit removed , i needed to file off the sharp edges of the HF PA input transformer LR322B 
The MA862 is dual diode SMD  band switch
< 0.7 OHM    Cd  1pF or less
this hard to get part can be replaced by 2 BA591,135
having same specs


btw  finally decent pictures again the 2 pictures above are token
with a new Huawei P10 lite replacing HTC with broken  camera
 besides the excellent camera the P10 is much faster
Unlock easy with fingerprint scanner at the back
i do advice the smart view cover for protection
And do not take this phone with you to Barcelona if you want to keep it...

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