[Drake] FS-4

[Garey Barrell]

Raymond -

The connection to the R-4C is a little strange, not intuitive.  

First, use low capacity cable, and as short a length as possible.  RG-62 
will work, although it is stiff and susceptible to damage from 
soldering.  RG-59 is also OK.   Avoid use of the small (RG-174, RG-188) 
coax, as it is fairly high capacity.

Next, you can not use a "crystal plug" on the receiver end.  The center 
conductor needs to have a pin the diameter of a crystal pin.  This pin 
is plugged into any one of the crystal sockets on the back panel.  The 
crystal sockets are all tied together by a bus wire that runs around the 
entire board.  Your cable needs to plug into any socket, but must plug 
into the side that is connected to the that bus, NOT one of the 
individually wired pins.  The shield of the cable needs to be attached 
to the chassis of the receiver, NOT to any of the crystal socket pins.  
NO termination resistor is required.  The XTAL switch must be set to any 
position WITHOUT a crystal plugged in.

Lastly, if you want to go back to using a crystal, either the internal 
or the accessory crystals, the FS-4 cable must be disconnected.

Sherwood Engineering <http://www.sherweng.com/ham.html#fs-4> offers an 
interface kit to take care of all this, but it isn't cheap!

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 4-B, C-Line & TR-4/C Service Supplement CDs
<www.k4oah.com>



Raymond Perkins wrote:
> Does the cable connecting the FS-4 frequency synthesizer to R-4C need anything special to connect to the receiver? Can I use a direct shielded cable? Does it have to coax? Perhaps RG62/U?  
>
> Only description I have found on internet thus far is a home-brew synthesizer that had a cable with a shunt resistor and in-line capacitor at the end to connect to R-4C. Is this necessary on a cable I intend to use? Thanks for your help.
>
> 73 Raymond  w5vpu
>   
>