[TowerTalk] FT1000MP

Rod Ehrhart dxengineering at dxengineering.com
Wed Jan 13 12:48:33 PST 2010


The actual thread of this post should be: Receive Antenna Input Switching and Protection
 
John, the device you are looking for is known as a Receive Antenna Interface for Transceivers, available from DX Engineering as
model DXE-RTR-1. It offers automatic and manual RX INPUT disconnection and RX OUT switching so you can easily listen to either your
receive antenna system or the transmit antenna. It is keyed by the transceiver AMP keying line, and offers full QSK capability with
4 ms response.
 
See this new item at this link: http://www.dxengineering.com/ProductDetail.asp?ID=306
<http://www.dxengineering.com/ProductDetail.asp?ID=306&SecID=155&DeptID=12> &SecID=155&DeptID=12  
 
and the DXE-RTR-1 manual is at this link: http://www.dxengineering.com/pdf/RTR-1-Rev1.pdf
 
Bob, what you are hearing is only receiver muting. The FT1000MP manual does not say that the RX ANT connection to the front end is
disabled during transmit. Previous posts related that RX ANT input does not disconnect during transmit. As confirmed by tech
support, Icom transceivers purposely do not disconnect the RX IN to the front end during transmit as detailed in the copy from the
RTR-1 manual:  
 
"Most high-end transceivers, old and new, offer a receive antenna input that DOES NOT interrupt RF or switch off during transmit,
even though the receiver is muted, very quickly in full break-in CW operation. This is a design feature which allows an operator to
listen to a receive antenna, located a sufficient distance away from the transmit antenna to prevent receiver front end damage,
allowing very fast QSK operations. However, most Amateurs who own this type of radio do not have access to the real estate for the
required antenna separation to support this type of operation. Unfortunately, several hams have discovered these facts the hard way,
after unintentionally blowing the front end of their expensive transceiver with transmitted RF riding in on their receive antenna
feedline. Also, on many transceivers, connection of a receive antenna to the RX (antenna) IN port requires removal of the "RX OUT to
RX IN" jumper patch cable, and then the transmit antenna cannot be heard. Recommendations for external relays and other devices have
not addressed the need for protection as well as switching options. The DXE-RTR-1 fills this need with an attractive and versatile
accessory." 
 
Originally intended to allow the connection of receive antennas and devices to transceivers that do not have a receive antenna
input, we believe that the QSK capable RTR-1 unit will also help you, and many other Amateurs, with a simple, attractive and
practical station accessory.
 
73,
 
Rod Ehrhart - WN8R
DX Engineering Customer Support
dxengineering at dxengineering.com <blocked::mailto:dxengineering at dxengineering.com> 
Orders 800-777-0703
Tech Support 330-572-3200
 <blocked::http://www.dxengineering.com/> www.dxengineering.com


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