TenTec
[Top] [All Lists]

[TenTec] Power Limiting Omni VI+

To: <tentec@contesting.com>
Subject: [TenTec] Power Limiting Omni VI+
From: at060@chebucto.ns.ca (David McClafferty)
Date: Wed, 27 Oct 1999 18:07:07 -0300 (ADT)
Does the Pegasus work this way as well? I noticed they don't stress for a
tentec PS or a circuit breaker as they did with the older Tentec rigs.
When lightening took out the finals in my Pegasus the power supply (Tentec
961) shut down on voice peaks. Can I assume it would have protected itself
on any supply?
                                        73,Dave, VE1ADH


On Wed, 27 Oct 1999, Dave Bowker wrote:

> 
> The collector current to the PA output transistors is monitored as a voltage
> drop across R5 (0.015 Ohm/10W) on the DC input board and fed to op amp U2
> and Q14 on the 9 MHz mixer/IF board.  U1B compares the set power level (as
> determined by the front panel RF PWR control) to the preset current  (as set
> by R54 with the RF PWR control fully clockwise) and controls a pin-diode
> attenuator consisting of D18/D19.  If the PA collector current exceeds a
> preset level of 22 amps the RF drive available at connector-27 (TXD OUT) is
> reduced to protect the PA transistors.
> 
> Essentially, the PA is capabable of operating into a dead short or open, or
> anything between, until the safe collector current point is reached.  You
> can always maintain a lower output power under high SWR conditions by
> backing off on the RF PWR control.
> 
> 73, Dave, K1FK
> Fort Kent, ME
> 
> 
> --
> FAQ on WWW:               http://www.contesting.com/tentecfaq.htm
> Submissions:              tentec@contesting.com
> Administrative requests:  tentec-REQUEST@contesting.com
> Problems:                 owner-tentec@contesting.com
> Search:                   http://www.contesting.com/km9p/search.htm
> 


--
FAQ on WWW:               http://www.contesting.com/tentecfaq.htm
Submissions:              tentec@contesting.com
Administrative requests:  tentec-REQUEST@contesting.com
Problems:                 owner-tentec@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm


<Prev in Thread] Current Thread [Next in Thread>