[TenTec] Orion XVTR RF output

[Carl Moreschi]

Actually there is an ALC even for the transverter output.  It stabilizes the
drive in SSB and CW so that the output is limited and can't go beyond the
set value. There is no connection provided to connect an amplifier back to
the radio for feedback ALC.

Carl Moreschi N4PY
121 Little Bell Drive
Bell Mountain
Hays, NC 28635
----- Original Message ----- 
From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Tuesday, May 22, 2007 7:46 PM
Subject: Re: [TenTec] Orion XVTR RF output


> On Tue, 2007-05-22 at 09:35 -0700, Rick Williams wrote:
> > Thanks for the reply Martin.  I'm running 2.060b firmware.
> >
> > I am using an SSB model LT6S six metre transverter.  The transverter has
a
> > built in adjustable attenuator and the input required is adjustable from
1
> > mW to 500 mW.  I have adjusted the transverter attenuator so that 20
watts
> > output (maximum spec of the transverter) is delivered when the Orion PWR
> > setting is at 100.  According to the Orion manual, the power setting
adjusts
> > the XVTR RF output to between +5dBm and +15 dBm (about 3 mW to 30 mW).
> >
> > The power settings are not the issue for me.  The issue is adjusting the
MIC
> > gain to obtain adequate ALC indication.  There is no problem in CW.  (I
> > successfully worked Hawaii on CW yesterday so I know it's working!)
> >
> > I've also received a reply (off the reflector) from a user encountering
the
> > "problem" I have described while operating a Down East Microwave
> > transverter.
> >
> > I guess the issue here is shouldn't the ALC setting be independent of
> > whether a transverter is attached to the XVTR RF output connector?  Or
am I
> > way off base here?
> >
> > 73,
> >
> > Rick
> > VE7TK
> >
> Primarily ALC is to protect the internal PA, to limit the drive so the
> intermod is acceptable. A secondary effect is to correct the analog
> transmitter gain for variations from band to band that ordinarily are
> present. When using the low level output that ALC detector isn't in the
> circuit and there isn't the power that's present for normal antenna
> connections to develop a useful ALC voltage, though its sure that a
> special ALC detector could be created to have sufficient voltage. There
> probably is a external ALC input for connecting to the PA. There could
> be an ALC detector at the input or the output of the transverter
> connected there. Just take a bit of work to customize it for the
> transverter.
>
> Transverters for VHF in G3SEK's book, "The VHF/UHF DX Book," do include
> an input ALC and variable attenuator for transverter protection. There's
> no reason that detected output couldn't control the exciter with ALC
> input instead and no fundamental reason ALC couldn't be created by a
> directional coupler at the antenna side of the transverter and that way
> it could protect the transverter stages from over drive too.
> -- 
> 73, Jerry, K0CQ,
> All content copyright Dr. Gerald N. Johnson, electrical engineer
>
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