I am very new to the 6400M and need some help.

Andy W3LI

I am very new to the 6400M and need some help. I have my HF ant on "A" and my 7el 6m beam on "B". I can't seem to be able to do this. Maybe it can not be done?????

Mark_WS7M

N9VC

Andy W3LI

That sure defeats the idea I was looking for. I was hoping to get rid of some 6m gear. So why have antenna input 2 or A and B when all I can use is "A"  and antenna input 1 ??? 

N9VC

Read my above post. You can switch between antennas and use both A & B.
But if you wish to receive on both slices, they have to use a common antenna.
Such as 6 meters, A on 50.125 and the other up on a digital freq.

Bill -VA3WTB

N9VC is correct, both antenna ports share the same single SCU on the 6400M. In order to make them independent you need the 6600 or 6700 radios.

bahillen

Andy I was confused with the antennas and SCU and band filtering when I ordered a 6400 2 years ago. While waiting for delivery I started looking at how the SCU works and it’s relation to antennas. I changed my order to a 6600 4 months later. I still didn’t understand the operating impact even with the 6600. I have two antennas for Tx/RX and since added two receive antennas. The radio can select between 6 connectors on the radio that can be used for receive on HF. Two ANT 1 and Ant 2, Two RCVR A and B and Two XBTR A and B. All selectable from the front panel. Really cool and a great capability from the front panel and automatically switching with Persistence or Global Profiles. (XVTR A and B must be used cautiously because you can transmit low level RF if not careful.) BUT only Two antennas can be active at one time to the radio / SCUs for the 6600 and One for the 6400. Here is the RUB, when you change RX antennas on a Slice that is use concurrently by other Slices the other slices may also change RX antennas unexpectedly. Sometimes you have to put all slices on one SCU then select the RX antennas one at a time otherwise the software decides what it thinks you want not always what I want. You mentally have to think that an SCU is a receive antenna, One SCU equals One antenna for receive PERIOD. With a 6400 you may be able to find a duplexer than combines the two antennas into one receive input that is a possible solution. Even an antenna analyzer, a T and some coax maybe a relay to TX. As an example on 160 or 80m, I put my vertical on ANT 2 and a directional receive on RCVR B with two Slices on the same frequency. Very helpful on digital. Integration of antenna selection into the radio is a big deal for both models. Others have answered your basic question. I responded because I have struggled with how to get the most out of the Flex capability. Had I stayed with the 6400 I would have $2,000 in the bank and still have an unbelievable radio. I even thought I could have bought two 6400s and had more choices for the same money. You have options. 73 Bill W9JJB

Mark_WS7M

Good post Bill,

I personally like to think of an SCU as a true receiver. 

When you buy an Icom or Kenwood with "dual" receivers it is like getting 2 SCUs only the SCUs in the Flex are very likely much better.

With 2 SCU you can, in my experience, have them both pointed at a single RX antenna or have them pointed at different RX antennas.

For those of you with lots of space the 6600, 6700 makes it possible to have one SCU perhaps on your large 160m loop antenna and the other SCU connect to your 2000 foot 6m beam.

It would be like having two radios in one except you cannot transmit out both at the same time.  TX switching is very quick of course and assuming you either use the internal tuner or an external tuner you could almost instantly switch and TX on either one.

Al K0VM

K5ROX

I remember that same feeling.....