[TenTec] Omni vi+ and Alpha 87A

[David Drew]

I don't believe the 91B uses Pin-Diodes as do the 89 and 87A which I feel 
is probably the problem area because of the switching times and sequencing.

Dave W7DPW

At 06:47 PM 7/15/01 -0700, Greg Hodsdon wrote:

>I've been running an Alpha 91B for several years with an Omni VI+
>and have never experienced a tripping problem. Make sure Tx Out is
>connected to "Relay" and Tx En is connected to "Key Out".  Sounds
>to me you might be experiencing a hot switching problem
>Greg, K7KJ
>
>
>----- Original Message -----
>From: "John, ke5c" <ke5c@hot.rr.com>
>To: "Ten-Tec Reflector" <tentec@contesting.com>
>Cc: "George, K5TR" <geoiii@loja.kkn.net>; "Tom, N5TW" <n5tw@igg-tx.net>
>Sent: Sunday, July 15, 2001 12:32 PM
>Subject: [TenTec] Omni vi+ and Alpha 87A
>
>
> >
> > Last weekend my friend unplugged the cables from his FT1000D, removed it,
> > set my Omni vi+ into the same physical space, and reconnected the cables.
> > We determined the drive level which made his Alpha 87A happy.  (Jay, that
> > plus a three antenna stack of 15 total elements is why I was loud on the
>net
> > last week.)  He used the Omni and Alpha several times during the week, but
> > early on during IARU, I kept tripping the 87A out.  I reduced drive to get
> > about 1000W out instead of 1500W, and had the same *intermittent* problem.
> > I would make several QSO's without difficulty, not change the band or
> > antenna direction, and suddenly the 87A would trip out.  I soon noticed
>that
> > the forward and reflected power on the 87A jumped just as it kicked out.
> > Thinking maybe there was a loose connnection in the antenna system, I
> > changed from 40M to 15M with the same result.  We uninstalled the Omni and
> > put his FT1000D back in place, and I operated the next 12 hours without
> > difficultly.
> >
> > Another interpretation of the forward and reflected power surging would be
> > slow or poor ALC performance allowing a spike in the drive to the 87A
> > transiently harder.  Does anyone have any experience with the Omni vi+ or
> > perhaps just generically with TenTec power amps and ALC driving an 87A
>which
> > is just loaded with protection circuitry?
> >
> > 73, John
> > P.S. the FT1000D is a fine rig, I just wanted to operate with my own rig
>for
> > psychologic reasons, so no comparisons please.
> >
> >
> > --
> > FAQ on WWW:               http://www.contesting.com/FAQ/tentec
> > Submissions:              tentec@contesting.com
> > Administrative requests:  tentec-REQUEST@contesting.com
> > Problems:                 owner-tentec@contesting.com
> >
> >
>
>
>--
>FAQ on WWW:               http://www.contesting.com/FAQ/tentec
>Submissions:              tentec@contesting.com
>Administrative requests:  tentec-REQUEST@contesting.com
>Problems:                 owner-tentec@contesting.com


--
FAQ on WWW:               http://www.contesting.com/FAQ/tentec
Submissions:              tentec@contesting.com
Administrative requests:  tentec-REQUEST@contesting.com
Problems:                 owner-tentec@contesting.com