best way to isolate the 5K and 6K

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  • Updated 4 years ago
I have both the 5K and 6K. Both are powered by identical 50amp Astron powersupplies.
Both rigs are in close proximity to each other.
Now I do not wish to transmit on both rigs at the same instant.  But they could be in use as SingleOPMultiRadio.
So far, the 5K seems to be immune to the 6K operating (barefoot).
But if I transmit on the 5K, it will frequently put the 6K out of commission.
The 6K will require a reboot.
This will occur even if operating at less than 100 watts.
I'm well grounded, electrically and also to the water supply copper pipe.
(In Chicagoland all electrical connections must have a connection to the water supply pipe.
In my case it's copper out to the street connection to the water main. Also the outside electric meter service connection must have a direct to ground rod green wire connection.
Plus I'm in the basement which has copper tubing for heat in the concrete floor. *HI HI*
There are radials buried under mine and my neighbors sod. (that's another story, email me direct if your curious how that happened)

So after all of that, those of you with similar or multiple 6K radios, do you also have the problem of one rig shutting down the other?
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Bill-W9OL

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Posted 4 years ago

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Duane, AC5AA

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Here's a silly question - have you checked to see what, if any, is the voltage dip at the 6K when the 5K is keyed? 
(Edited)
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Bill-W9OL

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You know I never thought of that....but as I said, each is on it's own 50amp Astron iron power supply.
And each is on a different 120 circuit.
But...can't hurt to check that out...
Thanks for the suggestion.
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Al / NN4ZZ

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Bill,
I found that my 6700 is much more sensitive to RF than my other radios.  Before I fixed the problem the 6700 would frequently lock up when I touched the CW paddle.   So this was from RF from the radio getting back into the radio.  This could happen running barefoot but much more often when using my amplifier.  So I wouldn't be surprised that RF from another radio could also lock up the 6K. 

Like your setup everything in the shack is RF grounded (radio, tuner, amp, PC, etc).   I added an optical link for the radio network connection.    I put ferrites on every cable going in and out of the radio.  I did one cable at a time in order to see if there was one that had the most impact.  

The biggest improvement and fix came from adding ferrites on the antenna coax.  After adding a lot of ferrites to the antenna coax the problem was solved.  I didn't go back an undo all of the other changes but I think the RF coming back in on the antenna coax was the main issue. 

More detail in this older post also:

https://community.flexradio.com/flexradio/topics/rfi_shuts_down_the_6k_fast 

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com

   
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Mike

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Perhaps this is related. During Field Day, I was using a 6300. When we screwed up antenna switching or filters (not too often) the 6300 would operate into a very high SWR, and the radio would power off immediately (no shutdown sequence) when transmitting. Perhaps power from the 5000 is coming back into the 6700, simulating high SWR? It could screw up whatever calculates SWR -- no forward, high reflected (actually power from the 5000)
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Bill-W9OL

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Thanks Al
I do have ferrites on the cables, but if some are good...more should be better? LOL
Will do
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Bill-W9OL

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I'll keep playing. It's one of those things, change one thing, and maybe goof up something else.
Thanks for all the suggestions.
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Al / NN4ZZ

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Bill,
In my case I have about 14 ferrites on the coax cable between the radio and my amplifier.  And that cable passes through them twice.



Plus the cable is a Wireman coax balun with ferrites already on one end.



Note: the cable I have is longer than shown in the picture. 

And finally on the LMR600 coax from the amplifier to the antenna are another 20 ferrites.   It took that much to fix the problem in my case.   But I have zero lockup problems now.  

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com

 
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Carl/K5HK

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Gotta love those common mode/current balums!
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KY6LA - Howard, Elmer

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Single Point Ground?

You describe the fact that you have an effective ground but do you have everything in your shack going to a single point (Star Configuration)?    I found that I had ground loops with multi-point grounds that were easily cured when everything went to a single point ground

Of course, I also agree with AL....You can never have too many ferrites
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Bill-W9OL

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My omission. All in shack equipment goes to the SAME basement waterpipe ground connection. The only difference is that the length of the ground cables in all these cases is different.
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K6NOK- Bill

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I run a Kenwood TS-590 and my Flex 6300 from the same 75 amp Astron power supply, and use an Alpha Delta coax switch to switch either rig into the antenna. The "Non selected" rig antenna line is grounded. Have absolutely no problems at all in this configuration.

Perhaps it has something to do with running separate power supplies? Might be interesting to try hooking both rigs up to the same power supply and see how it acts.
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Bill-W9OL

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Done dat! got da same result. LOL
That's the reason I went with a 2nd power supply.
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James Kirk

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Are they each connected to different antennas simultaneously, or are do they go to an antenna switch?
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Bill-W9OL

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They all use the same antenna system. Each antenna 'CAN BE' routed to either rig. But obviously no need to use both rigs on same band at same time. One time Rig A may be on 40, and Rig B could be on 20. Next day that could be reversed or all together different bands. Just depends what I'm chasing and where.
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James Kirk

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Just to understand, is say one radio connected to a 20m antenna and the other to a separate 40m antenna. If so, then the receiving radio is getting a lot of RF into from the near field of the other. 
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WX7Y

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I think your problem is that RF is getting into the Radio, Computer, and / or Ethernet Switch / Router CAT5 cabling and you may want to put a bunch of Fair-rite beds on the Ethernet cables and / or use Shielded CAT5 cables.

The only problem I have had even at 1500 Watts is that my Flex6700 Antenna relay falses and disconnects the receiver to protect the 6700 on voice peaks from other radios transmitters, (Flex5K, TS590, or IC7000 doesn't matter) on antenna's separated by 100' feet even running JUST 100 Watts.

This makes it pretty hard to run the radio in a field day or other event where multiple receivers / transmitters are involved.

I reported this a long time ago to Flex.

At home I have a reversed Antenna switch that grounds the unused ports which stops the relay chattering and prevent possible damage to the 6700.
73's
Bret, WX7Y
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Dudley - WA5QPZ

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Bill,

Do you have a field strength meter?   Remember the old CB SWR meters,   had a field strength meter built in..  Mine is two tone green, says HeathKit on the front..   If you have RF in the shack,  it's like beach sand,  gets into everything.   You would be surprised of all the things that get fixed when the common mode RF is resolved.    There are some good articles concerning Common Mode,  do a Google search..     Back to the field strength meter,  I keep mine setting on my amp,  with the pot turned all the way up, but if I see the meter come off the "0" peg,   I have either had an antenna fall down,  blown coax connector, or feedline issues..    Verticals and off center fed antennas are the worst about common mode RF backing up on the feed line.    It gets into everything, routers, switches, alarm systems , wife's landline,  TV and even makes the dogs bark...   :-)   

Dudley