Amps
[Top] [All Lists]

[AMPS] ALC from SB-200 reduces FT-900 power on CW

To: <amps@contesting.com>
Subject: [AMPS] ALC from SB-200 reduces FT-900 power on CW
From: km1h@juno.com (km1h@juno.com)
Date: Wed, 23 Sep 1998 18:58:29 -0400
On Wed, 23 Sep 1998 14:32:06 -0700 (PDT) david wintheiser
<w0opw@yahoo.com> writes:
>
>I cranked up my old SB-200 with the Yaesu FT-900 driver 
>and discovered that the FT-900 power was reduced to 50 watts.  This
>was on CW !!.  Removing the ALC line brought the drive power back up
>to 100 watts.

And leave it off. That ALC circuit was designed for tube exciters and is
not compatible with the SS gear.  Anyway your 990 has a real good
internal ALC and it should keep the SB-200 from overdrive problems. 
Just be sure to load the 200 up to full output with 100W (700-800W with
good tubes) and then use the ALC control on the 990 to keep the 200 voice
peaks to about 60% of key down.


> Does anyone have experience with this anomoly on SB-200's ??
> Rich,  if your monitoring this, I bought 2 of your kits for 572b's
>this spring but can't remember what you 
>recommend for Cathode swamp resitors instead of ALC.


Dont bother;  you wasted a few bucks......a 990 can not hurt a SB200. The
only "if" I am aware of is with some Svetlana tubes which tend to be
rather squirrely in any amp......particularly a FL-2100.

73   Carl  KM1H
Amplifier Repair and 6M Conversions Our Speciality ( SB200 and 220 series
in particular). Ask for a free flyer.

>
>
>
>
>_________________________________________________________
>DO YOU YAHOO!?
>Get your free @yahoo.com address at http://mail.yahoo.com
>
>
>--
>FAQ on WWW:               http://www.contesting.com/ampfaq.html
>Submissions:              amps@contesting.com
>Administrative requests:  amps-REQUEST@contesting.com
>Problems:                 owner-amps@contesting.com
>Search:                   http://www.contesting.com/km9p/search.htm
>
>

_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]

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


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