On Thu, 24 Sep 1998 08:53:30 +0200 "John Fielding"
<johnf@futurenet.co.za> writes:
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>I was under the impression that a sort of standard existed for ALC
>control
>voltages. Usually a negative going output form the linear is used to
>reduce the drive from the exciter. I seem to remember that most rigs
>need
>about -6V to -9V to fully back off the drive. Or have things changed
>?
>
>John ZS5JF
I seem to remember some rigs requiring a positive ALC in the past.....TR7
maybe?
There are also some older amps that can return in excess of -20V
.......their original voltage doubler circuits had to be rebuilt.
I know I had problems with a TS-930 some years back when taking it to
various stations to contest.....finally just quit using the ALC. Reset
the internal power control to 90W out ( which wouldnt overdrive any amp)
and just refrained from screaming into the mike.
73 Carl KM1H
>
>----------
>> From: km1h@juno.com
>> To: amps@contesting.com
>> Subject: Re: [AMPS] ALC from SB-200 reduces FT-900 power on CW
To: <amps@contesting.com>
>> Date: Thursday, September 24, 1998 12:58 AM
>>
>>
>>
>> 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
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><html><head></head><BODY bgcolor=3D"#FFFFFF"><p><font size=3D2 =
>color=3D"#000000" face=3D"Arial">I was under the impression that a
>sort =
>of standard existed for ALC control voltages. Usually a negative
>=
>going output form the linear is used to reduce the drive from the =
>exciter. I seem to remember that most rigs need about -6V to -9V
>=
>to fully back off the drive. Or have things changed =
>?<br><br>John	ZS5JF<br><br>----------<br>> From: <font =
>color=3D"#0000FF"><u>km1h@juno.com</u><font color=3D"#000000"><br>>
>=
>To: <font color=3D"#0000FF"><u>amps@contesting.com</u><font =
>color=3D"#000000"><br>> Subject: Re: [AMPS] ALC from SB-200 reduces
>=
To: <amps@contesting.com>
>FT-900 power on CW<br>> Date: Thursday, September 24, 1998 12:58 =
>AM<br>> <br>> <br>> <br>> On Wed, 23 Sep 1998 14:32:06
>-0700 =
>(PDT) david wintheiser<br>> <<font =
>color=3D"#0000FF"><u>w0opw@yahoo.com</u><font color=3D"#000000">> =
>writes:<br>> ><br>> >I cranked up my old SB-200 with the =
>Yaesu FT-900 driver <br>> >and discovered that the FT-900 power
>=
>was reduced to 50 watts. This<br>> >was on CW !!. =
> Removing the ALC line brought the drive power back up<br>> =
>>to 100 watts.<br>> <br>> And leave it off. That ALC circuit
>=
>was designed for tube exciters and is<br>> not compatible with the
>SS =
>gear. Anyway your 990 has a real good<br>> internal ALC and
>it =
>should keep the SB-200 from overdrive problems. <br>> Just be sure
>to =
>load the 200 up to full output with 100W (700-800W with<br>> good =
>tubes) and then use the ALC control on the 990 to keep the 200 =
>voice<br>> peaks to about 60% of key down.<br>> <br>>
><br>> =
>> Does anyone have experience with this anomoly on SB-200's =
>??<br>> > Rich, if your monitoring this, I bought 2 of
>your =
>kits for 572b's<br>> >this spring but can't remember what you =
><br>> >recommend for Cathode swamp resitors instead of =
>ALC.<br>> <br>> <br>> Dont bother; you wasted a few =
>bucks......a 990 can not hurt a SB200. The<br>> only "if"
>I =
>am aware of is with some Svetlana tubes which tend to be<br>>
>rather =
>squirrely in any amp......particularly a FL-2100.<br>> <br>> 73
>=
> Carl KM1H<br>> Amplifier Repair and 6M
>Conversions =
>Our Speciality ( SB200 and 220 series<br>> in particular). Ask for
>a =
>free flyer.<br>> <br>> ><br>> ><br>> ><br>> =
>><br>> =
>>_________________________________________________________<br>>
>=
>>DO YOU YAHOO!?<br>> >Get your free @yahoo.com address at
><font =
>color=3D"#0000FF"><u>http://mail.yahoo.com</u><font =
>color=3D"#000000"><br>> ><br>> ><br>> >--<br>> =
>>FAQ on WWW: =
> &=
>nbsp; <font =
>color=3D"#0000FF"><u>http://www.contesting.com/ampfaq.html</u><font =
>color=3D"#000000"><br>> >Submissions: =
> &=
>nbsp;<font color=3D"#0000FF"><u>amps@contesting.com</u><font =
>color=3D"#000000"><br>> >Administrative requests: <font =
>color=3D"#0000FF"><u>amps-REQUEST@contesting.com</u><font =
>color=3D"#000000"><br>> >Problems: =
> &=
>nbsp; <font =
>color=3D"#0000FF"><u>owner-amps@contesting.com</u><font =
>color=3D"#000000"><br>> >Search: =
> &=
>nbsp; <font =
>color=3D"#0000FF"><u>http://www.contesting.com/km9p/search.htm</u><font
>=
>color=3D"#000000"><br>> ><br>> ><br>> <br>> =
>_____________________________________________________________________<br>=
>> You don't need to buy Internet access to use free Internet =
>e-mail.<br>> Get completely free e-mail from Juno at <font =
>color=3D"#0000FF"><u>http://www.juno.com</u><font =
>color=3D"#000000"><br>> Or call Juno at (800) 654-JUNO =
>[654-5866]<br>> <br>> --<br>> FAQ on WWW: =
> &=
>nbsp; <font =
>color=3D"#0000FF"><u>http://www.contesting.com/ampfaq.html</u><font =
>color=3D"#000000"><br>> Submissions: =
> &=
>nbsp;<font color=3D"#0000FF"><u>amps@contesting.com</u><font =
>color=3D"#000000"><br>> Administrative requests: <font =
>color=3D"#0000FF"><u>amps-REQUEST@contesting.com</u><font =
>color=3D"#000000"><br>> Problems: =
> &=
>nbsp; <font =
>color=3D"#0000FF"><u>owner-amps@contesting.com</u><font =
>color=3D"#000000"><br>> Search: =
> &=
>nbsp; <font =
>color=3D"#0000FF"><u>http://www.contesting.com/km9p/search.htm</u><font
>=
>color=3D"#000000"></p>
></font></font></font></font></font></font></font></font></font></font></f=
>ont></font></font></font></font></font></font></font></font></font></font=
>></font></font></font></font></font></font></font></font></font></font></=
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___________________________________________________________________
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Or call Juno at (800) 654-JUNO [654-5866]
--
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Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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