[1000mp] RX antenna port

[Pete Smith]

I thought I recalled being told on this list any number of times that the 
"RX ant in" jack is, in fact, disconnected from the receiver during 
transmit.  Not so?

For SO2R, rather than disconnecting or shorting the RX antenna terminal, 
wouldn't you need to use a passive limiting protective device, one with a 
small resistor in series and maybe 4 diodes in shunt? On the Mark 5, I 
believe you can use the RX antenna switch position and all received signals 
will pass out through the "RX ant out" jack and in through the protector 
and the "RX ant in jack."

At 02:42 AM 3/18/2005, Jeff Maass wrote:


> > -----Original Message-----
> > From: 1000mp-bounces at mailman.qth.net
> > [mailto:1000mp-bounces at mailman.qth.net]On Behalf Of Barrie Smith
> > Sent: Thursday, March 17, 2005 8:22 PM
> > To: All about Yaesu 1000mp
> > Subject: [1000mp] RX antenna port
> >
> >
> > I'm going to be installing a K9AY loop as a 160M RX antenna soon.
> >
> > Is the RX port in any way protected during transmit on the MKV?
> >
> > Or, will I be building/buying something to short the port out during
> > transmit?
> >
> > 73, Barrie, W7ALW
> >
>
>Barrie:
>
>The "RX In" port of the MKV is not shorted during
>transmit. It's a good idea to protect it.
>
>First thing, any RX antenna will work best if
>located as far as possible from the resonant transmit
>antenna. If in close proximity, noise will be couple
>from the transmit antenna to the receive antenna.
>A little distance also decreased the amount of signal
>coupled back to the RX In port when transmitting.
>
>Protection is easy to provide. You can build a simple
>disconnect relay to mount at the radio, or commercially,
>there are:
>
>    KD9SV's Front End Saver ($60 from Radioware):
>       http://www.radiobooks.com/products/fes.htm
>
>    K9AY's RIP-1 ($35 from Array Solutions)
>       http://www.aytechnologies.com/Products/RIP1data.htm
>
>These are quick, and disconnect the RX antenna from the
>transceiver before the amplifier is keyed. The AY Technologies
>RIP-1 link above includes a schematic so you can get an
>idea of how it is connected.
>
>I've been using one of the KD9SV Front End Savers since
>1997, and have a couple at the PJ2T contest station. I
>just bought one of the RIP-1 to try as well.
>
>73,
>
>Jeff Maass  K8ND
>
>
>
>______________________________________________________________
>1000mp mailing list
>Home: http://mailman.qth.net/mailman/listinfo/1000mp
>Help: http://mailman.qth.net/mmfaq.html
>Post: mailto:1000mp at mailman.qth.net