IC-746 FAQ
are driven by transistor Q1302. The transistor is not a hardy as the relay, with obvious
consequences.
Summary
We have now identified MANY possible failure conditions for the SEND relay.
*
Too much voltage
*
Too much current (switching or carrying)
*
V/C spiking from inductive loading
*
Accidental AC operation
*
Exceeding operational rate
*
Exceeding expected lifetime
*
Connection confusion
Those are the reasons for using an external SEND relay.
3.5.6
My SEND relay seems to be stuck, what do I do?
Ultimately, you'll have to replace it, either yourself or via Icom service.
It is possible (battle field repair) to free the contacts by tapping the relay till it frees; but
YMMV! Actually, it takes a fair amount od disassembly to access the relay, and this solution
is temporary at best.
3.5.7
Where can I get an external switching relay?
You have several to choose from:
Ameritron
ARS
702
Ameritron
ARB
704
MFJ
ARB-702-I
MFJ
ARB-704
W2ENY Amplifier Interface
Yaesu
FRB-757
Users of older amplifiers (like the Heathkit SB-200) will want to check out the "soft key"
modules from:
http://www.harbachelectronics.com/
or a similar product, the AmpKeyer, at:
http://www.theheathkitshop.com/ampkeyer.html
Heil Sound makes a foot switch that can control both PTT and amplifier switching, in the
correct sequence.
http://www.heilsound.com/FS-2-Dual-Footswitch.htm
KD9SV has a "Front-End-Saver" switchers that can handle extra antennas along with the
amplifier.
Page 47 of 113
2003-02-08
