[1000mp] RX Ant Input Status Rx/Tx Not Always Open - 160 m reception

[WD8ARZ]

It depends on what receive antenna option is selected as to the condition of
the RX antenna input connector during transmit.

On my FT-1000MP:

Antenna A or B selected, no RX antenna in connector selected, DC ohm meter
check shows no reading during receive and transmit (ie open at the rca
connector on the rear of the mp).

However when RX antenna connector is selected using the ANT A/B RX buttons
(rx antenna jack is selected, not A or B for receive), there is a DC 82 ohms
measured during receive OR TRANSMIT on the RX in antenna RCA connector on
the rear of the mp.

This means something internal to the RX in antenna RCA jack is exposed to
the Rf environment when the RX antenna selection option is enabled.

I would be more concerned to a open connection arcing (small relays don't
have much space between relay contact points), than to a shorted input in
place before Rf emitted.

Of course this doesn't detail the switching 'internally' prior to the
connector, or what receive components are exposed to the rf path effects
that are much different than a dc ohm meter path.

Until a trace is made of the information provided by Yaesu on this
circuitry, their information is still what we have to go by (as detailed in
my last email on this topic). Yep, there is generally a difference between
the text descriptions, pictorial flow charts, schematics, wiring diagrams,
and what actually goes out the door in the hardware (or for that matter
hardware and firmware) to the customer ......

What I would do is as summarized in my last email ..........

However, one of these days I plan on doing some verification of the pictoral
and schematic information to nail this one once and for all..... ah for the
time .... hi hi

73 from Bill - WD8ARZ
wd8arz#ix.netcom.com