Is the 6500 a true 'full duplex' radio?

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  • Updated 5 years ago
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if my transmitting and receiving antennas are sufficiently well isolated, that is...i.e. will i be able to listen on 80m while i'm transmitting on 40m, for example ?

73
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W5XZ - dan

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Posted 6 years ago

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Al K0VM, Elmer

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It apppears to me the answer is yes... If you have sufficent isolation between your RX and TX antennas. ... I have RX antenna selected for RXA with 14.220 on slice A and 7.229 on slice B..
TX is on slice A with ANT1 .. Seems to work.. You likely want to get the TX signal into the RX antenna down to the -20dbm range or less.. (just guessing, I dont have a good number on this )

AL, K0VM
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K4EAR

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The only problem is, the antenna matrix switching can get fubared up with .13.10, making changes.
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Al K0VM, Elmer

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I did more testing.. I have windom on ANt1 and a multiband vertical on RXA .. Looks like I have about 50 db isolation betyween the two. There appears to be very slight increawse in 40m noise floor when the talk on 20m.. This is likely due to broad band noise in the Transmit chain ( PA ). If I transmit on 14.200 and have the have the second RX slice on 14.340, the braodband noise floor increases about 15db so in band woul be more of a chalange.

AL, K0VM
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W5XZ - dan

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thanks, Al...I am guessing a guy would want to use relatively narrow slices to insure the band-pass filters are switched in also ? maybe ???

73, dan, W5XZ
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Al K0VM, Elmer

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If your on two different bands, there can be no band pass filter.. You only get wide.

AL, K0VM
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Tim - W4TME, Customer Experience Manager

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Band pass filter selection is dependent on the width of the spectrum display and the frequency of the slice(s), not the slice filter width.
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W5XZ - dan

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i guess i meant to say 'slice panadapter width', since that seems to auto-switch the BPF's in and out..

but maybe it's moot, if, as AL says, 'you only get wide if you're on 2 different bands...'
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Tim - W4TME, Customer Experience Manager

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My point is that there is a mix of syntax here that might be confusing to a person reading this post. A slice does not have a Panadapter width. A slice receiver is an element within the context of a spectrum display (panadapter).
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Steve - N5AC, VP Engineering / CTO

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Official Response
The radio hardware has some capabilities that you would consider full duplex. There are limits to what can or that you would want to do and we have not yet spent any time looking into this. For the immediate future, we are muting receivers when transmitting, but only when the transmit signal is on the air so the muting is a very narrow window. This allows for QSK operation on a separate antenna that is "almost full duplex." I think if you try it you will agree you get a significant amount of "program material" out of the receiver. For sideband, we mute all during the transmit (in the next version) to avoid issues with AGC being driven around by your transmit signal. Longer term, we may do more in the way of full duplex, but it will require some investigation and decisions about what makes sense for you and the radio. I know this is a little wishy-washy, but it's the situation at present.
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W5XZ - dan

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of course, i'm thinking SO2R...at some point, for me anyway...wondering if those nice BPF's can snap back and forth quickly enough...or, if external ones will still be necessary....most of the signals in a dx contest are quite weak, of course...

perhaps this only makes sense to me? or, more likely, i don't know what i'm talking about! ha
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Greg

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I understand what you are getting at Dan. I am not sure it will be possible with the 6500. With the 6700 you have the two SCUs and a compliment of BPFs for both of them. You should be able to say work 20M with ANT1 (SCU1) and 15M on ANT2 (SCU2) at the same time ....I think. That is how I understood it from the start and one of the reasons for getting the 6700 over the 6500.

73
Greg
AB7R
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W5XZ - dan

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thanks, Greg...I thought the BPF's were only in the receive signal pathways...

hypothetical scenario: i'm trying to 'run' on 15m, sending repeated 'cq test..' the rate is dropping, and I want to check 10m one last time for multipliers while i'm trying to hold down my run freq on 15m. sure don't want to hear myself on 10 m...seems like i'd only really need the BPF on 10m, right?

say 10m opens back up a little, i still want to watch 15m...still, only need one BPF, now on 15m, I THINK.......

as the MUF drops, prob do same thing on 20 & 15, etc, etc... 73, w5xz, dan
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Don - ik2egl - ai4sd

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I hope that Flex will take into consideration the full duplex capabily
I like so2r and I wonder to use flex 6500 in this way !!
tnx

don

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KY6LA - Howard, Elmer

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I doubt that 6500 with only one SCU cvs do it. But the 2 SCU 6700 should be capable.