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Re: Preamp bypass circuit



>From: "Margaret Leber (K3XS)" <maggie@voicenet.com>
>K5OE@aol.com wrote:
>
>> The FT-847 has a similar function (and also lacks VOX).
>
>It sure does, labelled "MOX" right under the power switch. Easy to accidently
>punch them both. Does anybody know what that is *for*? I've never really
found a
>good use for it. Could it really just be so you could go walkabout in the
shack
>during a long transmission? 

The MOX button has never been a problem for me though I understand the
risk.  I have never pushed it by mistake {yet}.

Regarding its purpose, well...I have no use for it.  I guess it may have
use for those using an auto-antenna tuner.  Oh I get it--- it is the
cooling fan test switch...he! he!...or it is used by Alpha amplifier owners
to duplicate the mfr's 24 hour key-down test!  

It probably is like the appendix...serves no useful function but they had
one in prehistoric times [1950's AM days] when hams had separate xmtrs and
rcvrs and a xmit switch was mounted on the xmtr.  Mic cords were just one
conductor shielded cables on many of those old rigs.  Course AM was when
the term "rag chew" originated (maybe should have been called mic chew or
ham monologues ;-)  The tx switch saved one from holding down a PTT switch
for those long sessions!

Perhaps we should just perform an "MOXectomy"...cut the sucker out!
Actually, I was considring rewiring the MOX switch to control AGC-on/off.
I find it amusing that the little FT-817 has VOX and no MOX???  Also, AGC
can be switched off in the FT-817, not just fast/slow like in the
FT-847!...go figure!

As far as the problem of operating cross-band duplex with a sequencer,
probably means you need a sequencer for each band.  Then you force the
sequencer on the uplink band into Tx-mode.  Gosh wouldn't you think the
mfr's would have anticipated this for satellite operation?  Better would be
including sequencing internal to the radio with external relay contacts for
the preamp, coax relay, and PA's.  Bet you could program the cpu for this?
Maybe next millenium.  

Ed
licensed since 1958...Had one of them AM rigs.

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