Flex-6400 and Maestro

Mike-N1VE · March 2023

I want to use separate receive and transmit antennas. Can this be done on the Flex-6400? If so can you give me specific instructions about how to do it? I have read the manual and I don't understand whether or not it can be done.

Dan Trainor · March 2023

Hi Mike, Maestro is one of several client types. Other client types would be a Windows PC, An Apple MacBook, an iPad, etc. I needed to ask you if the Maestro was the client type you're using so I could tell you how to change your receive antenna. Each client type is slightly different menu system. Hope that makes sense. 73, de WA1QZX

John KB4DU · March 2023

The advantage of using the rx only antenna port is that it is impossible to accidentally transmit into the rx antenna. For example, a small loop with preamp would be very unhappy if it received a jolt of 100 watts of tx power.

Dan Trainor · March 2023

Yes, it can be done on 6400. If Maestro is your client type, then in the upper of screen touch your finger on:

ANT1 ANT1

change to:

RXA ANT1

This switches the receive antenna to the special "Receive Only" antenna RXA on the open slice(s).

On back of 6400, you have a BNC connector RX only antenna port. Connect your receive only antenna to this port.

If this is not enough info to get you started, reply back.

73, dan WA1QZX

Neil D Friedman N3DF · March 2023

I don't have a Maestro (yet), but couldn't Mike just use ANT1 for the receive antenna and ANT2 for the transmit antenna?

Dan Trainor · March 2023

Neil,

"I don't have a Maestro (yet), but couldn't Mike just use ANT1 for the receive antenna and ANT2 for the transmit antenna?"

Yup, then ANT1 would be a receive antenna and ANT2 the transmit antenna. That works. But, you can also utilize RXA which is a special extra "receive only" antenna port. Personally, I place an active broadband RX only Mag loop on this port. But you could use any antenna type on RXA. Or use ANT1 or ANT2 as receiving antenna within your slices.

Dan, WA1QZX

Mike-N1VE · March 2023

Thanks for the quick replies to my question. Dan said, "If it is the client type". How do I know if my Maestro is the client type?

KD0RC · March 2023

You can also use the XVTR port(s) for receive if they are not already occupied with a transverter.

Mike-N1VE · March 2023

Hi Dan,

Yes, I am using the Maestro to control the Flex-6400. I have owned the radio for several years but I have only a basic understanding of it. The terminology in the manual is often not clear to me. I understand that I can transmit on one antenna and receive on another. I will attach the receive antenna to the antenna BNC connection (RX) on the back of the set and see what I can do with setting up the Maestro properly. I appreciate you help and will get back to you whether or not I am able to get the rig working.

Mike

Mike-VA3MW · March 2023

I don't have a Maestro handy, but, yes you can. The process is the same, so you just want to touch in the same place.

On SmartSDR if you go to this screen

And tap on the Blue ANT, you will get a drop down list that will list all the antenna ports you can then use for receiving and just pick the one you want to use. (This is on a 6600 which has more antenna ports than a 6400--you won't see RX B and XVTB)

Here, on 160M, the RED ANT1 is my transmitting antenna and the Blue RX A is my receiving antenna.

Mike-N1VE · March 2023

Thank you for the information and the photos. I have been dealing with other problems with the Flex and other equipment, and this is the first time that I have been able to work on the TX/RX antenna situation.

I am using the Maestro and wonder if I have it set up properly for using one antenna for receive and one antenna for transmit.

Both slices look identical, though A should be the R7 antenna and B should be the end fed. When I (transmit low power) on Slice A, Slice B shows a receive signal.

The receive antenna is attached to the RXA antenna socket (BNC)

The transmit antenna is attached to ANT 1 (SO239)

Is there something wrong with my set up?

John KB4DU · March 2023

if I understand what you said, this is normal (correct). The rx only doesn’t get switched when the tx is keyed. So it will pick up the transmitted signal if the tx signal frequency is displayed on the panadapter. Both received signals will be the same if the antennas are similar.

Neil D Friedman N3DF · March 2023

While I am not entirely clear on your setup, note that the A and B slices, while they can simultaneously receive different bands or band segments, cannot utilize two different receive antennas at the same time. As the 6400 has only one spectral capture unit (SCU), the radio can only listen on one antenna at a time (the 6600 and 6700 each have two SCUs).

Your post seems to suggest that slice A is receiving on the R7 and slice B is simultaneously receiving on the end fed. This cannot happen.

I apologize if I have misinterpreted your post.

John KB4DU · March 2023

So, looking at the picture more closely the rxa port is feeding both panadapters for receive and ant1 for transmit. As Neal said, on a 6400 this is the only option. A 6600 will have the capability of using 2 different receive antennas with 2 scu’s, but there is still only one transmitter, so the tx antenna is the same for both panadapters. Your setup is fine the way it is.

To have a choice of antennas, connect the R7 to one antenna port and the end fed to the other, leaving the rx antenna connected as is. Then any one can be selected as the rx antenna and either R7 or end fed as the tx antenna, or either antenna can be both tx and rx as desired.

To address the question of the Maestro, the radio is the server of the data and the attached devices are the clients. The Maestro is always a client, and another client device (pc, iPad or another Maestro) can be connected and operated simultaneously using the multi flex capability contained in the 6400 if using version 3.xx of SmartSDR. They will share the single scu for receiving and share the single transmitter.

Mike-N1VE · March 2023

I appreciate the help getting the Flex to transmit on one antenna and receive on another antenna.

To be sure that we understand each other, below is a sketch of the antenna connections on the Flex.6400.

ANT 1 is for receive only.

RX A is for transmit only.

When I set up the Flex to use RX A to transmit, I get the following display on the Maestro.

Both slices show ANT 1.

When I transmit (low power), both slices show the transmitted signal.

It appears that I am transmitting on RX A.

If I am, my concern is that I am transmitting into the receiving antenna and will overdrive the receiver. Should I be concerned?

Thanks

Neil D Friedman N3DF · March 2023

You can’t transmit on the receive-only antenna (RX-A). The Maestro is set up to receive on RX-A and transmit on ANT1 on either slice.

Mike-N1VE · March 2023

I understand that I can't transmit with the receive-only antenna (RX-A). I misstated in my above message. I should have written "It appears that I am transmitting into ANT 1), since I can see my signal on both slices. But apparently that is normal and okay.

Thanks for getting back to me.

Flex-6400 and Maestro

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