* * * Two radio switching unit * * *

Having 2 radios, guess which? an FT1000 and the FT1KMPmkVField the couriosity was to switch
from one to the other and try to check which sounded better beside all other possibilities.
After some tweaking I decided to put all the circuitry in the old good SP 901P speaker.
Its box has lot of space inside:


All the switchery can be reduced into a 2 way 12 poles via an 8 pole rotary switch and a relay 2way\4poles
.and the interfaces from\to the SoundBlaster.



The audio cables in-out are wired for the stereo "Dual radio mode", as both radios have stereo capability.
The main control switches radio A or B , it is in the higer part of the panel; just below is the to connect an external audio-tape (in and out) MIC switches "Sblaster\Mic normal\Mic_contest.
An extra PTT socket, Led controls for CW and PTT and +Vcc from a general +13vcc psu.
The closed alu-box contains the audio preamp to raise the audio level coming from the rear AF_out socket.
The white cables are for the Linear-PTT switch, the black-red ones are for switching the CW_key.

Read the Note n1 below for more infos.


The quasi_completed switcher and its finished panel.

During the daily use, more options have come in mind to facilitate the use of each radio and the accessories around the table.
To get the Switcher modular , the original manual switch has been substituted with relays on a pcb,
so if more needs come it is quite easy to add new features.

-------Winter 2008---------
As I am using an SDR receiver, take a look on La Braciola link as external IF of the main rig or as 3rd RX, I wanted to add to my
Radio Switcher the option to use the SDR rx on both radios, so an external little box with a relay has been added to have
the possibility to view and ear from both radios either via the pc's speakers or dirtectly in the headphones.

Here is the block view of this further option.

Nothing difficult, but just a further feature to improve the reception in some circumstances when the main receiver
has not the possibility to remove QRM\QRN or to sharpen the actual RX window down to a very tight passage.

With the help of DX Lab Commander program both radio_CAT controls are connected, the radios are kept on the same frequency,
speeding up the tuning procedures.

• 2009 Foot notes :
  
  • n1) After some years of use the rotary switch has gone broken as it is not built for a continous use.
    so all the switchery has been changed with 12Vdc relais.
    Adding new options now is very easy and the RX signal path is very steady compared to the mechanical switch.
  
  
  • n2) ...
  
  
  • n3) ...

mar.04, dic.07, gen.09, lug.09