[TenTec] Keying Amp with my new Omni VI+

Robert & Linda McGraw K4TAX RMcGraw at Blomand.Net
Mon Jun 6 23:00:36 EDT 2005


One point often missed or not understood is the QSK keying process when 
using an amplifier.  In the case of the Paragon series and the Omni series 
the relay in the transceiver shouldn't be used to key the amp.  Tentec uses 
a "loop through" sequenced process for the QSK event timing.

I'll try to explain:
When the key is connected to the transceiver KEY jack on the rear and the 
key is closed (line goes low) here's what happens.  At this point the 
transceiver RF section is not activated. The control signal goes to the TX 
OUT jack (line goes low) which is connected to the KEY IN on the amp.  This 
line low keys the amp.  The transceiver is still not activated.  Once the 
amp QSK circuit is activated the input and output relays have switched and 
they have settled, then a signal is sent out of the KEY OUT jack (line goes 
low) of the amp.  This signal goes to the TX ENable jack on the transceiver. 
This is the point that the transceiver is activated and produces RF to drive 
the amp.  This sequence thus prevents hot switching within the amp.

If you elect to use the RELAY OUT on the transceiver to key the amp, you 
have no way to prevent "hot switching" within the amp.  The jumper is in 
place between TX OUT and TX EN on the back of the transceiver.  There is no 
delay to allow the amp relay(s) to switch and settle.  If your amp isn't a 
QSK capable amp, then you're on your own.  My suggestion is to use manual 
PTT and not try to use QSK operation.

73
Bob, K4TAX

 




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