TX signal asserted during TUNE output

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I'm going to check this when I get a chance after work, but is the TX signal asserted when the Flex 6300 is keyed using the TUNE button in SSRD 1.3.8? I'd like to use TUNE to tune my external Auto tuner, but don't want to key the amp.
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Mark Erbaugh

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Posted 4 years ago

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Nick - W2NER

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I think that's called putting the amp in standby?  ;-)...  I do this all the time.
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Chris DL5NAM

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Good joke !!!
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Steve N4LQ

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It keys the amp and of course the tuner won't like that. I learned the hard way. It might be nice to have an option not to though. 
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WX7Y

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What kind of Tuner are you running? Some Auto Tuners automatically kill the key line to the AMP which you run through the Tuner if the tuner begins to tune. This is the best method and safest for your AMP and Tuner.

Unfortunately not all the high power tuners do this and your stuck with going into standby manually

73's
Bret
WX7Y
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WH6HI - Pat

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The Elecraft KAT500 Tuner has the pass through feature to interrupt the key line.  When used with a tuner control app, such as the supplied Elecraft SW or DDUtil, Tune is initiated from the application then the tune button can be pressed on the Flex, which starts the tune process.  In the case of an automatic initiation of a re-tune the tuner will cut off the key line so that the tuner is not trying to tune at high power that could damage the Tuner.  This is the most common failure in Tuners as high power and high SWR may or will indeed burn out some of the inductors in the tuner. 
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Mark Erbaugh

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I just ordered a MFJ 998 auto tuner. It is supposed to have the amp disable feature, but I'm not sure how that will work with the Flex since it seems (from the manual I downloaded) that the amp disable works with radios that have automatic interfaces (which doesn't include the Flex).  According to the instructions, to tune with the tuner, you generate your 20w then push the TUNE button on the tuner. I'm concerned that until I push the TUNE button, the amp will be enable. If I could push the TUNE button on the tuner first then the TUNE button on SSDR, I think I would be okay.

Back when I had a SB220 and I was driving it with a TenTec Pegasus,  I built a SPDT center off switch into the key line. In the center off position, the key line was open - I could use that for tuning the tuner. In one position, the rig controlled the key line and in the other position, the key line was closed - I used that position for CW since the Pegasus only did QSK and the SB220 didn't support that.
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WX7Y

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The MFJ998 has Full auto mode and Semi-auto mode, What this means is in "Full Auto" no cable from the radio other then the Coax and the Key Line for the AMP control, The tuner see's the RF from the radio (at least 20 WATTs and I think no more the 100 Watts), it begins a tuning cycle and determines the best I and C for the SWR you've preset in the Menus, it memorializes this setting and has a built in Frequency counter that it uses for the memories and VERY quickly tunes to the correct Inductors and Caps to where it was the last time you used that frequency. 

In Semi-Auto mode you have to hit Tune on the radio then hit tune on the Tuner, 

You may have trouble using Full Auto Mode with it re-tuning if your Antenna changes impedance for some reason during a conversation like Antenna's hung in Tree's, or to small a Balun for the power your using ect.

hope this helps put your mind at ease.
73's
Bret
WX7Y
 
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Mark Erbaugh

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Thanks for the info. I was interested in semi automatic mode - tune when I want it to. My concern is if I hit TUNE on SSDR that that will trigger the amp before I hit TUNE on the 998 when the amp will be disabled, so for a few seconds the amp will be working into an untuned antenna. Worse, I don't know if the amp will drop out if it is still seeing RF from the Flex. The 998 has a Sticky Tune feature that may help. I just ordered the 998, so I haven't actually played with it yet.
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KK9W - Steve

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I believe this tuner needs a cable going from the tuner to the rig to be "automatic". A fully auto tuner would be a Palstar HF Auto.
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WH6HI - Pat

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Elecraft KAT500 also...
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WX7Y

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For the MFJ998, and the older Palstar AT-Auto tuners (not sure about the other Tuners) you will need JUST a RCA patch cable, same thing as you have laying around from the OLD VCR if your AMP uses a RCA jack like your Flex does.

The above Tuners have 2 (TWO) RCA female jacks one for AMP Key Input which goes to your Radio and one for AMP key output that goes to the AMP. 

Sounds like your on the right track and both of the above tuners work great configured this way.

73's
Bret
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Steve N4LQ

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Mark
I've had the MFJ-998 (indoor version) for about 4 years. It lives outside in a wx proof cabinet under the center of my doublet. LMR-600 goes between it and 100ft to the shack along with a pair of wires for the 12v power to the rig's Astron on the desk with an off/on switch. This is important when something goes wrong and a reset is needed. 
Sitcky Tune works great. I just send it 20 watts by pushing the tune button in SSDR and away it goes.
I have the Elecraft KPA-500 amp on line. Of course I make sure the amp is in standby/bypass mode when hitting the tune button otherwise the amp will kick in fault mode and make a big fuss. It's happend a few times but it's designed to handle situations like that.
I think you will enjoy the 998. 
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Anthony Bowyer

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DDUTIL has a few options that might be handy for you. The 998 has that option to disconnect ptt going to the amp when tuning. Problem is, there is nothing coming from the Flex to tell it TUNE was clicked. There is an option in DDUTIL that can be setup to put the amp in standby and initiate a tune cycle, at whatever power level you want. I use it with an LDG AT-1000 Pro II in full auto mode.

In my case, I first and ran a tune cycle on each band with low power from the xcvr to set the memories. I then set ddutil to key the xcvr for 2-3 secs at a specific power level, putting the amp in standby during that period.

This isn't perfect, because I would much rather have an output that says "the tune cycle is complete" and if it found a match or not, then use this to determine what to do next. It also requires that Tune be initiated from ddutil rather than clicking Tune in SSDR. To somewhat overcome this limitation, I set the center button on the FlexTune control to start this cycle when I do a long hold of it.

You can probably use the switching option from the 998 to act as a "Tune Complete and OK" signal that can then be fed to an RS-232 port  (or some variation) setup for signaling input. This would be better than a timed cycle.

This works well for the most part, as long as I don't use the tune button in SSDR.
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Mike James - WJ7U

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Anthony,

How did you get DDUTIL to initiate a tune, but not key the amp?

Thanks,
Mike WJ7U
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Anthony Bowyer

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So I don't miss a step. I'll need to make sure of all the details (sitting at the PC). I'll try to get the details to you as soon as I can. It requires a couple of macros. Basically does the same thing as the stby option.
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Anthony Bowyer

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I haven't forgotten you! Might be this Sat before I can get the info to you. Not really hard, but there are a few steps
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Anthony Bowyer

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I have this in a PDF or Word. Needed a few pics. Not a simple way I can see here to upload it, unless I convert it all to a graphics format. If you want, email me at adb1x1 at yahoo.com and I'll send this to you