[Amps] Re: Drake L7 newbie

[Dudley Hurry]

I have a L7 and with 80 watts drive you get about 1200 output.   With 100
you will get 1400, 125 will yield legal limit.   Do you want to push the
powersupply that hard?   Cooling the powersupply with an aux fan is a
necessary thing to do, but the 3-500s are very capable of producing the
power.    Be careful of the bandswitch, keep it clean and NEVER switch it
with the amp keyed..

A good step-start is a good ideal, but like the old SB220s they have run 30
years without it..    But after all that time being boxed up, it would not
surprise me that the filter caps are dried out and need to be replaced.
That would be my number one mod..

Thanks and 73's,
Dudley
WA5QPZ
jhurry at austin.rr.com


----- Original Message ----- 
From: <jsb at digistar.com>
To: "R_Davis" <WD8JJA at arrl.net>
Cc: <amps at contesting.com>
Sent: Friday, March 26, 2004 1:06 PM
Subject: Re: [Amps] Re: Drake L7 newbie


> On Fri, 26 Mar 2004, R_Davis wrote:
>
> > I know that the older amplifiers were marketed when the power limit in
> > the USA, for amateur use, was 1000 watts DC input, instead of 1500 watts
> > PEP output.  And back then, one tuned the amplifier in reduced voltage
> > mde (CW, TUNE, however it is marked) for 1000 watts input (plate V x
> > plate I). Then switched to high voltage for SSB.  This was supposed to
> > result in still having 1000 watts average, or DC, on SSB, but with much
> > greater PEP.  Hence, 2000W PEP input.
>
> Hmmmmm, that explains why the L4-B is rated for input vs. output power.
>
> > Given todays higher output power limits, can these pre - 1500W limit
> > amplifiers be tuned up in high voltage or SSB mode for c. 1300-1400
> > watts out (whatever they will do, up to 1500 watts)?
>
> I'm curious to know the answer to this question as well...  Seems like it
> wouldn't matter for CW operation other than greater wattage output on CW.
> But for SSB I can't say...  so i'm very curious to hear all the details
> from the others on this list...
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps