[Hackrf-dev] Still hoping for PTT

[Chuck McManis]

Or to put it differently, :-) If the HackRF would enable the ANT bias when
it was transmitting then it would "just work" as they say.

On Tue, Jun 26, 2018 at 11:18 AM Gavin Jacobs <apriljunkbox at hotmail.com>
wrote:

> Dominic
> Thanks for that offer/suggestion, but it’s already done! I found the TX
> mode signal that drives the TX LED, and it was already brought out to P5.
> So All I had to do was solder some ribbon cable to P5 socket (which is not
> populated). I have it connected to my power amp such that it energizes
> whenever the Hackrf is in transmit mode.
>
> Jake
>
>
> On Jun 26, 2018, at 10:59 AM, Dominic Spill <dominicgs at gmail.com> wrote:
>
> I'm not certain, because I don't want to break portapack or other add on
> boards, but it may be possible for us to toggle a GPIO pin on one of the
> headers when we switch to TX mode, if that would help?
>
> Dominic
>
> On 20 June 2018 at 17:55, Gavin Jacobs <apriljunkbox at hotmail.com> wrote:
>
>> Chuck,
>> I have used the bias-t voltage on the hackrf to power an upconverter but
>> it isn’t easy to turn it on and off. The only method I know is to use
>> hackrf-transfer - but that doesn’t work when switching to/from rx & tx.
>>
>> Meanwhile I have brought the tx LED signal out from P5, and it is
>> switching the power amp on and off just fine.
>>
>> Jake
>>
>> On Jun 19, 2018, at 7:02 PM, Chuck McManis <chuck.mcmanis at gmail.com>
>> wrote:
>>
>> FWIW the idiomatic way to achieve this as far as I can tell is to send a
>> bias-T signal on the RF cable, basically its a DC offset on the cable which
>> the PA picks up and switches on. This lets you have short cables between
>> the PA and the antenna and its only one line to hook up (the antenna coax)
>>
>> On Tue, Jun 19, 2018 at 5:04 PM Gavin Jacobs <apriljunkbox at hotmail.com>
>> wrote:
>>
>>> Bernie
>>> That’s a great idea! I looked on the hackrf schematic and the signal for
>>> the TX LED is brought out to a (DNP) header - all I have todo is bring that
>>> signal out to my PTT circuit. Thanks for the suggestion!
>>>
>>> Jake
>>>
>>>
>>> On Jun 15, 2018, at 5:32 AM, Bernard Kobier <bernardkobier at tpg.com.au>
>>> wrote:
>>>
>>> I admit I have not tried this but what about using the TX LED to drive
>>> an optocoupler to switch the amp?
>>>
>>> Bernie
>>>
>>>
>>>
>>> On 11 Jun 2018, at 00:53, CJ Hicks <cjhicks at dadelus-engineering.com>
>>> wrote:
>>>
>>> Why not leave your exciter on and only PTT your power amplifier (PA)?
>>> Or use an RF to shunt your exciter signal into a dummy load.  Just a couple
>>> of random thoughts.
>>>
>>> CJH
>>>
>>> *From:* HackRF-dev [mailto:hackrf-dev-bounces at greatscottgadgets.com
>>> <hackrf-dev-bounces at greatscottgadgets.com>] *On Behalf Of *Gavin Jacobs
>>> *Sent:* Saturday, June 09, 2018 5:57 PM
>>> *To:* hackrf-dev at greatscottgadgets.com
>>> *Subject:* [Hackrf-dev] Still hoping for PTT
>>>
>>> Has there been any progress on implementing digital i/o from/to the
>>> hackrf One. I'm hoping that someday the hackrf can supply a PTT signal to
>>> an external amplifier.
>>>
>>> Jake
>>>
>>> _______________________________________________
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>>> HackRF-dev at greatscottgadgets.com
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>>>
>>>
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>>
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>>
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