[AMPS] FT100D driving Alpha 87a

Einar Persson sm3mxr@swipnet.se
Sat, 28 Jul 2001 11:48:31 +0200


Hi Curt
I know a Swedish guy who has made some little box that would do what you ask
for.
It has independent maximum output adjustment for every HF-band in the FT1000.
Hearsay states that it works perfect. No more problem with over driving pa's.
He has also made another box for the FT1000 that automatically choose the
correct
antenna (if you have one - of course!) when you change band.
I'll try to find the guys email address.

73 // SM3MXR // Einar


Curt Terwilliger wrote:

> I am using an FT1000D to drive an Alpha 87a, and am thinking of building a
> "DC ALC" circuit to throttle back the juice to 60-80W out whenever the amp
> is in "Operate" mode (because otherwise one day in the heat of battle I will
> forget to reduce the drive power manually and probably cook the 3CX800s).
>
> This would not be RF derived ALC, just a DC voltage applied in steady state
> to reduce the power in the same manner as turning down the drive control on
> the front panel.
>
> AG6K, to whom I earlier mentioned this plan, has observed that using
> suitable cathode resistors might be a more simple and reliable way to allow
> the Alpha to accept a full 200W of drive. Point taken, although I am not
> keen on adding 100W of dissipation to the cathode compartment and am willing
> to take my chances with the reliability of an active circuit.
>
> I was wondering what others think about this DC ALC approach, and if anyone
> is currently using it?
>
> Tnx es 73,
>
> Curt W6XJ
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
>
> --
> FAQ on WWW:               http://www.contesting.com/FAQ/amps
> Submissions:              amps@contesting.com
> Administrative requests:  amps-REQUEST@contesting.com
> Problems:                 owner-amps@contesting.com



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