TX Relay settings

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  • Updated 6 years ago
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If I understand it correctly, each of the tx relay lines are adjustable on the settings transmit tab. Entering 10ms for TX1 causes the TX1 keyline to delay 10ms.

There is also one transmit delay field. What is the relationship between this setting and those for the key lines? It seems that the TX delay should be set higher than any of the three TX relay lines, correct?

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Posted 6 years ago

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Photo of Dudley - WA5QPZ

Dudley - WA5QPZ

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Correct, normally the sum of the total TX 1-3 keying should be less than the TX output delay, but would depend on what you are keying. With a normal HF amp, you would want to leave the TX1-3 at default vaule and have the TX delay at maybe 10 or 15 ms .. Gives time for the amp's T/R relays to settle . But no more than 50 ms, but depends on the mode . QSK CW would have to be on the low side, where SSB modes can be rather long.
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Steve - N5AC, VP Engineering / CTO

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TX_Delay is added to the end of all of the TX1,2,3 settings and then RF will exit the transmitter.
Photo of Dave-N9CHM


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Quick question, I just leave my 3 TX relays set at 0, which is the default I assume. I only operate SSB, and haven't had any problems switching the Alpha amp (374A) or switching the Pixel antenna relay. Any problems leaving the relays set at zero?
Photo of K4EAR


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Only if those in/out relays in the amp switch faster than the TX output of the 6xxx radio from a RX-TX transition and the 374A output relay side can hold closed longer than it takes the flex to decay down on RF out with a PTT release. These are semantics but important.
Stomp-to-talk footswitch, probably no issue...VOX is an unknown, as I don't use it without headphones, since there is no anti-vox. If I had a Rigol scope here I would measure and post the 6xxx transition times not using the CW "0" delay settings for QSK CW using pin diodes, but the internal reed relays for SSB.
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Thanks for the input. I'll set my TX relays at 10ms, just to be on the safe side.