Satellite communications using 6400?

Dom wa2got

Is it possible to communicate with satellites using a Flex 6400? If it is possible could you direct me to where the additional components needed are described and to where they should be connected to the Flex? I suspect I would need 2 transverters, one for 2m and one for 70cm, minimally. Although, I have seen a single (box) transverter that is capable of both 2m & 70cm. I am unsure if the 6400 would be able to utilize 2 transverters at the same time. Appreciate the input and Thanks.

Neil D Friedman N3DF

6400 has only one provision for a transverter.

Dom wa2got

jrboddie for satellite communications one would need to use 2 transverters. One for the uplink and another for the downlink. Both uplink and downlink frequencies are outside the band coverage that is available in the Flex. So transverters would be needed. Since the 6400 can only accommodate 1 transverter to be physically connected, it is impossible to be able to work satellite QSOs. It became clearer to me that this is the case when I looked at the connections on the flex 6400 for a transverter. There is only 1. Whereas the 6600 has 2.

John KB4DU

Start with page 113 of the SmartSDR v3 manual.

Dom wa2got

Thanks John for pointing out that section on the manual about transverter setup. I also found a video created by Mike from Flex and he makes a comment in the video about satellite communications. That it is possible on a 6600 because it has, in his words, "2 unique radios". He does not make mention of the 6400 for satellite communications. But perhaps satellite communications using transverters is only possible with the 6600. I believe the answer is that satellite communications is not possible with 6400. Have I reached the correct conclusion. Appreciate confirmations on that conclusion.

John KB4DU

Dom;

I'm not doing this, only referencing the manuals. I believe Mike is referring to full duplex satellite operations, which is possible on the 6600 because it has 2 scu’s and 2 transverter ports, allowing it to transmit and receive at the same time. The 6400 has only 1 scu and 1 transverter port, so it can’t do full duplex. The transverter port on the 6400 is there just for transverter operations and should function in simplex mode.

There are several operators on here that are using transverter, they should chime in.

Good luck

jrboddie

I am confused about this because the 6400 is advertised as:

2 Independent Band / Mode Receivers
Full Duplex Cross-Band Operation

So, with the proper transverters, why not?

John KB4DU

In flex speak with 2 independent receivers, I am currently monitoring 40M and 20M at the same time with panafall for each on a 6400. Again in flex speak there is only 1 signal capture unit (scu) and 1 associated transmitter, so the 6400 can either receive or transmit, but not both at the same time. The scu can display signals in two separate bands, or two separate frequencies in the same band. But only 2 in the 6400. The 6600 has two scu’s which lets it display 4 bands/frequencies, and listen on one scu while the other is transmitting (full duplex). The reviews in QST have more explanation.

Neil D Friedman N3DF

According to Sec. 33 of the 6400M/6600M User Guide, “All FLEX-6000 Signature Series Transceivers are inherently capable of full duplex operation....FDX is only possible if the two Slice Receivers are using separate physically isolated antennas.”

When FDX is enabled, the non-transmitting Slice Receiver will continue to receive.

John KB4DU

Well, I did not know this. Since I have recently installed a rx only antenna, I had to try it. And it works great with tx on 20 and rx on 40 simultaneously. Now I’m even more impressed with the 6400. Thanks for the tip.

KD0RC

Seems like you could set up the uplink (transmit) transverter on the XVTR port and the downlink (receive) transverter on RXA. Then, as Neil suggests, put it in full duplex (FDX) mode. Any reason that would not work?

Dom wa2got

Interesting thought Len. I do not see an RXA port on the 6400. But do see an RX IN port. Has anyone in the community done this, used a 6400 for satellite communications?

KD0RC

Using the 6400 for satellite work would definitely be second best to using a 6600 or 6700. Using RX A (RX In) instead of a second XVTR port means that there would be no frequency translation for the display. In other words, you would see a 28 MHz frequency instead of the actual downlink frequency, but you would see the proper uplink frequency because of the capabilities of the XVTR port.

I don't know if the satellite programs would do frequency tracking using the RX port as opposed to using XVTR A and B ports, so that might be another consideration.

All in all, a serious satellite user would certainly opt for a 6600 or 6700!

arodland

@KD0RC: actually, not true. You can get the frequency translation on any port, not just the XVTR ports. Just select the transverter from the band select and the Flex does the rest. There's zero downside to using a RX port for the receive side of a transverter.

But there is an issue with using the 6400 for full-duplex with transverters, and it relates to the thing that @jrboddie quoted. The 6400 supports "full-duplex cross-band operation". It can transmit on one port and receive on another as long as those ports are operating on different bands. But say you have a 144 to 28 MHz transverter and a 432 to 28 MHz transverter, and you want to work V/U satellites. As far as the Flex is concerned, those *aren't different bands*, they're both 10 meters. Your TX signal will deafen the receiver and you won't be able to do full-duplex, because the Flex doesn't have enough internal isolation for same-band signals.

To fix this you could use transverters with IF frequencies on two different bands, or get a 6600/6700, which can do "same band" full-duplex.

jrboddie

Thanks @arodland . That was a good explanation for me.

KD0RC

@arodland , thanks for that clarification!

Patrick

The common IF problem is why I upgraded from a 6500 to a 6700. But I wanted to use just one radio. One can use two radios and achieve full duplex. I am currently building what you might call a unifier box. It contains all the extra stuff to do V/U operation. The needed capabilities were satisfied by a nice small 432 MHz transverter, an LPA to satisfy the need to drive external power amps, both V/U. and relays set to allow signal switching to achieve full duplex for single band operation. All set up and switched via profiles. Having multiple TXx ports gives flexibility for selecting switching for simplex/duplex. I can monitor UHF repeaters while operating on VHF repeaters. I also use diplexers for single antenna operation. It has been a fun home brew project leveraging the power of Flex radios.