Steppir PTT connection to 6600

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It is probably simple question, but i did not find the answer yet.
I know i can use DDutil to inhibit TX during Steppir tune.
But I also have PTT interlock board on the SDA100 Steppir controller.
How can I connect Steppir Controller to the Flex to prevent TX during Steppir tune?
It seems like PTT connector on the back of the radio has a differnt purpose also TX1-TX3 as well.
Thanks
Sergey, KN7K
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Sergey Abrikosov

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Posted 3 weeks ago

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Neal Pollack, N6YFM

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Does the SteppIR controller have an output signal for TX Inhibit?

On the back of the Flex, the accessory connector has;  Pin 9
[Page 24 & 25 of the hardware manual]

7.8 TX REQUEST INPUT (INTERLOCK)  PIN 9

This RCA connector is provided to receive an interlock signal from external amplifiers, or other external equipment. When enabled it will prevent the FLEX-6400/FLEX-6600 from going to transmit. The TX Request Input can be enabled with a 3.3V to 5V logic signal (when in Active High mode) or connecting to ground (when in Active Low mode).

The circuit is a 74LVC14 CMOS Schmidt trigger logic input with a 2.7k pullup to +3.3V. The IC is 5V tolerant, so you can drive it with TTL levels as well. It can also be driven with an open collector transistor or open drain MOSFET. Grounding the center pin of this connector will prevent transmit from engaging (when in Active Low).

Refer to the SmartSDR documentation for information about how the interlock system works and how to determine what is preventing transmit. The SmartSDR for Windows Software User’s Guide also includes details on how to interlock two radios from simultaneous transmit for a Multi/2 operation.

Cheers,

Neal

(Edited)
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Sergey Abrikosov

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Hi Neal,
Thanks for reply.
I saw this information in manual but got a little confused.
I installed ptt board in Steppir SDA100 controller yesterday and tested it.
It seems like there is an internal relay on Steppir controller makes a short contacts on ptt output during antenna tuning.
I should be able to connect the ground to pin9 of the flex as far as I understand, right?
Sergey, KN7K
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Neal Pollack, N6YFM

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I think so.   I have never looked at a SteppIR controller or antenna.
But the PIN-9 accessory connector WILL prevent the flex from transmitting
if the appropriate logic level is applied.    In the Flex SmartSDR SOFTWARE user manual,
on page 158, you will see there is a setting on the radio setup dialog box, TX TAB,
about halfway down the dialog box, for "Interlocks - TX REQ".

The Interlocks section offers three setting for RCA TX and Accessory TX: Disabled, Active High and Active Low. The FLEX-6300 does not have interlock settings for RCA. In the Disabled position, the connector or accessory pin will not perform any function. In the Active Low setting, transmit will be prevented if the connector/pin are driven to ground. In the Active High setting, transmit will be prevented if the connector/pin are “high” or driven to some voltage level above ~1.5V.


---
Does your SteppIR controller put out it's own RF signal for tuning, or does it still
expect your transceiver to put out 5 watts for tuning?   Is it the transceiver you want
to disable during tuning, or is it your amp you want to disable?
The above interlock will not permit the flex 6600 to transmit ANY rf until the interlock
is removed.

Neal


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Sergey Abrikosov

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Neal,
Steppir does not provide any RF, it is all from Radio.
If you do not have any interlock and by mistake will push 1.5kW it can be damaged.
Anyway, I will have to play with that pin 9 on accessories output.
Thanks for your help.
Sergey
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JohnSweeney

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The SteppIR relay option is a normally closed circuit and is open during tuning.  It was designed to go in series with an amplifier keying line.   The SteppIR EHU's will generally handle normal exciter power if you accidentally transmit while it is tuning, so not sure the TX interlock is needed.   But the Flex does have that input.  You would have to build a small inverter circuit or use a relay to convert the normally closed switch in the SteppIR to a normally open for use with your Flex.
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Sergey Abrikosov

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John,
I do not believe i have to build anything.
I think i can provide a Gnd signal from Steppir Controller to Pin 9 of Accessory connector and and like Neal said set it to Low.
Need time to test it.
Not sure will complete this week because of contest and also get complications with Antenna Genius that I am trying to setup.
Thank for the help.
Sergey, KN7K