[TenTec] Transmit not stopping when PTT is released

Bob McGraw - K4TAX RMcGraw at Blomand.net
Thu Dec 5 21:28:24 EST 2013


In most cases with a non-QSK amp some form of delay system should be 
employed.  This system provides a delay at initiation of transmit such that 
amp relays close and settle before RF is applied.  Then at the end, a delay 
to hold the relays closed until the completion of the last character.  At 
end when the CW key is released the character must still be sent.  If the 
radio is using the CW key for control of the TX/RX control then likely the 
amp could un-key before completion of the RF envelope.  Thus hot switching 
may occur.

I don't recall the timing sequence of the Orion II.

With the Tentec QSK circuit the key is closed and this sends the signal to 
the amp to switch from RX to TX mode. After the amp has switched it then 
sends a signal back to the transceiver to deliver the RF.  At the end of the 
transmission, the RF sensing circuit in the Centurion and Titan keep the 
relays in the amp engaged until the end of the RF envelope before the relays 
are allow to switch from TX back to RX.


73
Bob, K4TAX




----- Original Message ----- 
From: "Barry N1EU" <barry.n1eu at gmail.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Thursday, December 05, 2013 6:56 PM
Subject: Re: [TenTec] Transmit not stopping when PTT is released


> Kim, you might be right - Rod's qrz page indicates a 1960's amplifier.
>
>
> On Fri, Dec 6, 2013 at 12:51 AM, Kim Elmore 
> <cw_de_n5op at sbcglobal.net>wrote:
>
>> Depends on how it's set up, but a long delay between keying and
>> application of RF drive, along with a delay between the cessation of RF
>> drive and unkeying the amp is needed to give the typical open-frame relay
>> time to switch.
>>
>> Kim N5OP
>>
>> "People that make music together cannot be enemies, at least as long as
>> the music lasts." -- Paul Hindemith
>>
>> On Dec 5, 2013, at 18:44, Barry N1EU <barry.n1eu at gmail.com> wrote:
>>
>> > Why would there be hot switching if the Orion is keying the amp?
>> >
>> >
>> > On Fri, Dec 6, 2013 at 12:42 AM, Kim Elmore <cw_de_n5op at sbcglobal.net
>> >wrote:
>> >
>> >> Unless the amp is QSK capable or he sets the OII to behave as semi 
>> >> QSK,
>> >> he'll almost certainly suffer hot switching of the T/R relay. Very 
>> >> bad.
>> >>
>> >> Kim N5OP
>> >>
>> >> "People that make music together cannot be enemies, at least as long 
>> >> as
>> >> the music lasts." -- Paul Hindemith
>> >>
>> >> On Dec 5, 2013, at 17:57, Richards <jrichards at k8jhr.com> wrote:
>> >>
>> >>> Golly, Rod... I am no expert... but I will take a stab at it.
>> >>>
>> >>> Are you sure you have the amp cable routed correctly?
>> >>>
>> >>> My "intuition"  (i.e. my gut) says you might consider routing
>> >>> the  amp key line from the rig to the amp, and just keying
>> >>> the rig with the microkeyer device - as if it were just a code
>> >>> key or PTT switch.n  That way, the keyer cues the rig, and the
>> >>> rig cues the amp.
>> >>>
>> >>> Just a thought...
>> >>>
>> >>> -------------------------------  
>> >>> K8JHR  ------------------------------
>> >>>
>> >>> Rod Greene wrote:
>> >>>> I just installed a new to me microKeyer II.    ....
>> >>> _______________________________________________
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