From: Garey Barrell 
Subject: Re: [drakelist] FS-4 Problem


Marty -

No service manual that I know of.

Check supply voltages.

DeoxiT the switches.

Check the 74192 divide-by-N (U3) and associated control 
logic (U4 & U8) on the A300 Digital board.  Board closest to 
the back.  I have seen more than a few of the 74192 chips 
fail.  Don't know why.

Check the 7490 divide-by-ten (U1) also on the A300 Digital 
board.  This is supposed to divide the 5MHz clock by ten to 
provide the 0.5 MHz reference to the phase detector.

Let us know what you find.

73, Garey - K4OAH
Atlanta



Allen (Marty) Martin wrote:
> The .5 frequency does not function correctly instead of switching .5 mhz it
> switches a full 1 mhz. Everything else seems to work o.k. Is there a tech
> manual downloadable any where?
> 
> Thanks
> Marty
> 
----------------------------------------------------------------------
Submissions:        drakelist{at}www.zerobeat.net
Subscribe:          majordomo{at}www.zerobeat.net - subscribe drakelist in body
Unsubscribe:        majordomo{at}www.zerobeat.net - unsubscribe drakelist in body
Hopelessly Lost:    majordomo{at}www.zerobeat.net - help in body of message
Brought to you courtesy of TLCHost.net  http://www.tlchost.net/
----------------------------------------------------------------------

---